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Fluid,Electrolyte,andAcid–BaseBalanceLEARNING OUTCOMESAfter completing this chapter, you will be able to:

1. Discuss the function, distribution, movement, and regu-lation of fluids and electrolytes in the body.

2. Describe the regulation of acid–base balance in thebody, including the roles of the lungs, the kidneys andbuffers.

3. Identify factors affecting normal body fluid, electrolyte,and acid–base balance.

4. Discuss the risk factors for and the causes and effects offluid, electrolyte, and acid–base imbalances.

5. Collect assessment data related to the client’s fluid,electrolyte, and acid–base balances.

6. Identify examples of nursing diagnoses, outcomes, andinterventions for clients with altered fluid, electrolyte, oracid–base balance.

7. Teach clients measures to maintain fluid and electrolytebalance.

8. Implement measures to correct imbalances of fluidsand electrolytes or acids and bases such as enteral orparenteral replacements and blood transfusions.

9. Evaluate the effect of nursing and collaborative inter-ventions on the client’s fluid, electrolyte, or acid–basebalance.

CHAPTER

52

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hematocrit, 1449hemolytic transfusion reaction,

1473homeostasis, 1424hydrostatic pressure, 1427hypercalcemia, 1441hyperchloremia, 1442hyperkalemia, 1438hypermagnesemia, 1442hypernatremia, 1438hyperphosphatemia, 1442hypertonic, 1427hypervolemia, 1435hypocalcemia, 1441hypochloremia, 1442hypokalemia, 1438hypomagnesemia, 1442hyponatremia, 1438hypophosphatemia, 1442hypotonic, 1427hypovolemia, 1435insensible fluid loss, 1428interstitial fluid, 1425intracellular fluid (ICF), 1424intravascular fluid, 1424ions, 1425

isotonic, 1427metabolic acidosis, 1442metabolic alkalosis, 1442milliequivalent, 1425obligatory losses, 1429oncotic pressure, 1427osmolality, 1427osmosis, 1426osmotic pressure, 1427overhydration, 1437peripherally inserted central

venous catheter (PICC), 1456pH, 1432pitting edema, 1436plasma, 1424renin-angiotensin-aldosterone

system, 1429respiratory acidosis, 1442respiratory alkalosis, 1442selectively permeable, 1426solutes, 1426solvent, 1426specific gravity, 1449third space syndrome, 1435transcellular fluid, 1425volume expanders, 1456

acid, 1432acidosis, 1433active transport, 1428agglutinins, 1472agglutinogens, 1472alkalosis, 1433anions, 1425antibodies, 1472antigens, 1472arterial blood gases (ABGs), 1449bases, 1432buffers, 1433cations, 1425central venous catheters, 1456colloid osmotic pressure, 1427colloids, 1426compensation, 1442crystalloids, 1426dehydration, 1437diffusion, 1427drip factor, 1465electrolytes, 1425extracellular fluid (ECF), 1424filtration, 1427filtration pressure, 1427fluid volume deficit (FVD), 1435fluid volume excess (FVE), 1435

KEY TERMS

In good health, a delicate balance of fluids, electrolytes, andacids and bases is maintained in the body. This balance, or phys-iologic homeostasis, depends on multiple physiologicprocesses that regulate fluid intake and output and the move-ment of water and the substances dissolved in it between thebody compartments.

Almost every illness has the potential to threaten this bal-ance. Even in daily living, excessive temperatures or vigorousactivity can disturb the balance if adequate water and salt intakeis not maintained. Therapeutic measures, such as the use of di-uretics or nasogastric suction, can also disturb the body’s home-ostasis unless water and electrolytes are replaced.

BODY FLUIDS AND ELECTROLYTESThe proportion of the human body composed of fluid is surpris-ingly large. Approximately 60% of the average healthy adult’sweight is water, the primary body fluid. In good health this vol-ume remains relatively constant and the person’s weight variesby less than 0.2 kg (0.5 lb) in 24 hours, regardless of the amountof fluid ingested.

Water is vital to health and normal cellular function, serving as

■ A medium for metabolic reactions within cells.■ A transporter for nutrients, waste products, and other

substances.

■ A lubricant.■ An insulator and shock absorber.■ One means of regulating and maintaining body temperature.

Age, sex, and body fat affect total body water. Infants havethe highest proportion of water, accounting for 70% to 80% oftheir body weight. The proportion of body water decreases withaging. In people older than 60 years of age, it represents onlyabout 50% of the total body weight. Women also have a lowerpercentage of body water than men. Women and the elderlyhave reduced body water due to decreased muscle mass and agreater percentage of fat tissue. Fat tissue is essentially free ofwater, whereas lean tissue contains a significant amount of wa-ter. Water makes up a greater percentage of a lean person’s bodyweight than an obese person’s.

Distribution of Body FluidsThe body’s fluid is divided into two major compartments, intra-cellular and extracellular. Intracellular fluid (ICF) is found withinthe cells of the body. It constitutes approximately two-thirds ofthe total body fluid in adults. Extracellular fluid (ECF) is foundoutside the cells and accounts for about one-third of total bodyfluid. It is subdivided into compartments. The two main com-partments of ECF are intravascular and interstitial. Intravascularfluid, or plasma, accounts for approximately 20% of the ECF

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CHAPTER 52 / Fluid, Electrolyte, and Acid–Base Balance 1425

and is found within the vascular system. Interstitial fluid, ac-counting for approximately 75% of the ECF, surrounds thecells. The other compartments of ECF are the lymph and trans-cellular fluids. Examples of transcellular fluid include cere-brospinal, pericardial, pancreatic, pleural, intraocular, biliary,peritoneal, and synovial fluids (Figure 52-1 ■).

Intracellular fluid is vital to normal cell functioning. It con-tains solutes such as oxygen, electrolytes, and glucose, and itprovides a medium in which metabolic processes of the celltake place.

Although extracellular fluid is in the smaller of the twocompartments, it is the transport system that carries nutrientsto and waste products from the cells. For example, plasma car-ries oxygen from the lungs and glucose from the gastrointesti-nal tract to the capillaries of the vascular system. From there,the oxygen and glucose move across the capillary membranesinto the interstitial spaces and then across the cellular mem-branes into the cells. The opposite route is taken for wasteproducts, such as carbon dioxide going from the cells to thelungs and metabolic acid wastes going eventually to the kid-neys. Interstitial fluid transports wastes from the cells by wayof the lymph system as well as directly into the blood plasmathrough capillaries.

Composition of Body FluidsExtracellular and intracellular fluids contain oxygen from thelungs, dissolved nutrients from the gastrointestinal tract, excre-tory products of metabolism such as carbon dioxide, andcharged particles called ions.

Total body fluid40 liters

Cell fluid25 liters

Plasma3 liters

Interstitial andtranscellular fluid

12 liters

Extracellularfluid

15 liters

Figure 52-1 ■ Total body fluid represents 40 L in an adult maleweighing 70 kg (154 lb).

Many salts dissociate in water, that is, break up into electri-cally charged ions. The salt sodium chloride breaks up into oneion of sodium (Na�) and one ion of chloride (Cl�). Thesecharged particles are called electrolytes because they are capa-ble of conducting electricity. The number of ions that carry apositive charge, called cations, and ions that carry a negativecharge, called anions, should be equal. Examples of cations aresodium (Na�), potassium (K�), calcium (Ca2�), and magnesium(Mg2�). Examples of anions include chloride (Cl�), bicarbonateHCO3

�, phosphate HPO42�, and sulfate SO4

2�.Electrolytes generally are measured in milliequivalents per

liter of water (mEq/L) or milligrams per 100 milliliters(mg/100 mL). The term milliequivalent refers to the chemicalcombining power of the ion, or the capacity of cations to com-bine with anions to form molecules. This combining activity ismeasured in relation to the combining activity of the hydrogenion (H�). Thus, 1 mEq of any anion equals 1 mEq of anycation. For example, sodium and chloride ions are equivalent,since they combine equally: 1 mEq of Na� equals 1 mEq ofCl�. However, these cations and anions are not equal inweight: 1 mg of Na� does not equal 1 mg of Cl�; rather, 3 mgof Na� equals 2 mg of Cl� .

Clinically, the milliequivalent system is most often used.However, nurses need to be aware that different systems ofmeasurement may be found when interpreting laboratory re-sults. For example, calcium levels frequently are reported inmilligrams per deciliter (1 dL � 100 mL) instead of milliequiv-alents per liter. It also is important to remember that laboratorytests are usually performed using blood plasma, an extracellularfluid. These results may reflect what is happening in the ECF,but it generally is not possible to directly measure electrolyteconcentrations within the cell.

The composition of fluids varies from one body compart-ment to another. In extracellular fluid, the principal elec-trolytes are sodium, chloride, and bicarbonate. Otherelectrolytes such as potassium, calcium, and magnesium arealso present but in much smaller quantities. Plasma and inter-stitial fluid, the two primary components of ECF, contain es-sentially the same electrolytes and solutes, with the exceptionof protein. Plasma is a protein-rich fluid, containing largeamounts of albumin, but interstitial fluid contains little or noprotein.

The composition of intracellular fluid differs significantlyfrom that of ECF. Potassium and magnesium are the primarycations present in ICF, with phosphate and sulfate the major an-ions. As in ECF, other electrolytes are present within the cell,but in much smaller concentrations (Figure 52-2 ■).

Maintaining a balance of fluid volumes and electrolyte com-positions in the fluid compartments of the body is essential tohealth. Normal and unusual fluid and electrolyte losses must bereplaced if homeostasis is to be maintained.

Other body fluids such as gastric and intestinal secretionsalso contain electrolytes. This is of particular concern whenthese fluids are lost from the body (for example, in severe vom-iting or diarrhea or when gastric suction removes the gastric se-cretions). Fluid and electrolyte imbalances can result fromexcessive losses through these routes.

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1426 UNIT X / Promoting Physiologic Health

Na+

Na+

Na+

K+

K+K+

Mg2+

Ca2+

Plasma Interstitialfluid

Intracellularfluid

0

50

100

150

200CATIONS

HCO3–

HCO3–

HCO3–

HPO42–

HPO42–

HPO42–

SO42–

SO42–

Cl–

Cl–

Cl–

Plasma Interstitialfluid

Intracellularfluid

0

50

100

150

200ANIONS

Org. acid

Proteins

Proteins

Mill

ieq

uiv

alen

ts p

er L

iter

(m

Eq

/L)

Figure 52-2 ■ Electrolyte composition (cations and anions) of body fluid compartments.Martini, Fredric H.; Halyard, Rebecca A., Fundamentals of Anatomy and Physiology Interactive, (Media Edition), 4th ed., © 1998. Reproduced with permission of PearsonEducation, Inc., Upper Saddle River, New Jersey.

Higher concentration Lower concentration

Semipermeablemembrane

Dissolvedsubstances

Watermolecules

H20

H20

H20

Figure 52-3 ■ Osmosis: Water molecules move from the lessconcentrated area to the more concentrated area in an attempt toequalize the concentration of solutions on two sides of a membrane.

Movement of Body Fluids and ElectrolytesThe body fluid compartments are separated from one another bycell membranes and the capillary membrane. While these mem-branes are completely permeable to water, they are consideredto be selectively permeable to solutes as substances move acrossthem with varying degrees of ease. Small particles such as ions,oxygen, and carbon dioxide easily move across these mem-branes, but larger molecules like glucose and proteins havemore difficulty moving between fluid compartments.

The methods by which electrolytes and other solutes moveare osmosis, diffusion, filtration, and active transport.

OsmosisOsmosis is the movement of water across cell membranes,from the less concentrated solution to the more concentratedsolution (Figure 52-3 ■). In other words, water moves towardthe higher concentration of solute in an attempt to equalizethe concentrations.

Solutes are substances dissolved in a liquid. For example,when sugar is added to coffee, the sugar is the solute. Solutesmay be crystalloids (salts that dissolve readily into true solu-tions) or colloids (substances such as large protein moleculesthat do not readily dissolve into true solutions). A solvent is thecomponent of a solution that can dissolve a solute. In the previ-ous example, coffee is the solvent for the sugar.

In the body, water is the solvent; the solutes include elec-trolytes, oxygen and carbon dioxide, glucose, urea, amino acids,and proteins. Osmosis occurs when the concentration of soluteson one side of a selectively permeable membrane, such as thecapillary membrane, is higher than on the other side. For exam-ple, a marathon runner loses a significant amount of waterthrough perspiration, increasing the concentration of solutes inthe plasma because of water loss. This higher solute concentra-tion draws water from the interstitial space and cells into thevascular compartment to equalize the concentration of solutes

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in all fluid compartments. Osmosis is an important mechanismfor maintaining homeostasis and fluid balance.

The concentration of solutes in body fluids is usually ex-pressed as the osmolality. Osmolality is determined by the totalsolute concentration within a fluid compartment and is mea-sured as parts of solute per kilogram of water.

Osmolality is reported as milliosmols per kilogram (mOsm/kg). Sodium is by far the greatest determinant of serum osmolality,with glucose and urea also contributing. Potassium, glucose, andurea are the primary contributors to the osmolality of intracellularfluid. The term tonicity may be used to refer to the osmolality of asolution. Solutions may be termed isotonic, hypertonic, or hypo-tonic. An isotonic solution has the same osmolality as body fluids.Normal saline, 0.9% sodium chloride, is an isotonic solution. Hyp-ertonic solutions have a higher osmolality than body fluids; 3%sodium chloride is a hypertonic solution. Hypotonic solutions suchas one-half normal saline (0.45% sodium chloride), by contrast,have a lower osmolality than body fluids.

Osmotic pressure is the power of a solution to draw wateracross a semipermeable membrane. When two solutions of dif-ferent solute concentrations are separated by a semipermeablemembrane, the solution of higher solute concentration exerts ahigher osmotic pressure, drawing water across the membrane toequalize the concentrations of the solutions. For example, infus-ing a hypertonic intravenous solution such as 3% sodium chlo-ride will draw fluid out of red blood cells (RBCs), causing themto shrink. On the other hand, a hypotonic solution administeredintravenously will cause the RBCs to swell as water is drawninto the cells by their higher osmotic pressure. In the body,plasma proteins exert an osmotic draw called colloid osmoticpressure or oncotic pressure, pulling water from the interstitialspace into the vascular compartment. This is an importantmechanism in maintaining vascular volume.

DiffusionDiffusion is the continual intermingling of molecules in liquids,gases, or solids brought about by the random movement of themolecules. For example, two gases become mixed by the con-stant motion of their molecules. The process of diffusion occurseven when two substances are separated by a thin membrane. Inthe body, diffusion of water, electrolytes, and other substancesoccurs through the “split pores” of capillary membranes.

The rate of diffusion of substances varies according to (a) thesize of the molecules, (b) the concentration of the solution, and(c) the temperature of the solution. Larger molecules move less

Higher concentration Lower concentration

Dissolvedsubstance Semipermeable

membrane

Figure 52-4 ■ Diffusion: The movement of molecules through asemipermeable membrane from an area of higher concentration to anarea of lower concentration.

quickly than smaller ones because they require more energy tomove about. With diffusion, the molecules move from a solu-tion of higher concentration to a solution of lower concentration(Figure 52-4 ■). Increases in temperature increase the rate ofmotion of molecules and therefore the rate of diffusion.

FiltrationFiltration is a process whereby fluid and solutes move togetheracross a membrane from one compartment to another. Themovement is from an area of higher pressure to one of lowerpressure. An example of filtration is the movement of fluid andnutrients from the capillaries of the arterioles to the interstitialfluid around the cells. The pressure in the compartment that re-sults in the movement of the fluid and substances dissolved influid out of the compartment is called filtration pressure.Hydrostatic pressure is the pressure exerted by a fluid within aclosed system on the walls of a container in which it is contained.The hydrostatic pressure of blood is the force exerted by bloodagainst the vascular walls (e.g., the artery walls). The principleinvolved in hydrostatic pressure is that fluids move from the areaof greater pressure to the area of lesser pressure. Using the ex-ample of the blood vessels, the plasma proteins in the blood ex-ert a colloid osmotic or oncotic pressure (see the earlier section“Osmosis”) that opposes the hydrostatic pressure and holds thefluid in the vascular compartment to maintain the vascular vol-ume. When the hydrostatic pressure is greater than the osmoticpressure, the fluid filters out of the blood vessels. The filtrationpressure in this example is the difference between the hydrostaticpressure and the osmotic pressure (Figure 52-5 ■).

Arterial side of capillary bed

Interstitialspace

Venous side of capillary bed

Direction of filtrationfluid and solutes

Direction of filtrationfluid and solutes

Capillary bed

Hydrostatic pressure(arterial blood pressure)

Hydrostatic pressure(venous blood pressure)

Colloid osmotic pressure(constant throughout

capillary bed)

Figure 52-5 ■ Schematic of filtration pressurechanges within a capillary bed. On the arterial side,arterial blood pressure exceeds colloid osmoticpressure, so that water and dissolved substancesmove out of the capillary into the interstitial space. Onthe venous side, venous blood pressure is less thancolloid osmotic pressure, so that water and dissolvedsubstances move into the capillary.

MediaLink

Mem

brane Transport Animation

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Intracellular fluid Extracellular fluid

Na+ Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+

Na+Na+Na+

Na+Na+

K+

Na+

K+

K+

K+ K+

K+

K+

K+

K+

K+

K+K+

K+K+

K+

K+

Cell membrane

ATP

ATP

ATP

ATP

Figure 52-6 ■ An example of active transport. Energy (ATP) is used tomove sodium molecules and potassium molecules across asemipermeable membrane against sodium’s and potassium’sconcentration gradients (i.e., from areas of lesser concentration toareas of greater concentration).

Active TransportSubstances can move across cell membranes from a less con-centrated solution to a more concentrated one by active trans-port (Figure 52-6 ■). This process differs from diffusion andosmosis in that metabolic energy is expended. In active trans-port, a substance combines with a carrier on the outside surfaceof the cell membrane, and they move to the inside surface of thecell membrane. Once inside, they separate, and the substance isreleased to the inside of the cell. A specific carrier is required foreach substance, enzymes are required for active transport, andenergy is expended.

This process is of particular importance in maintaining thedifferences in sodium and potassium ion concentrations ofECF and ICF. Under normal conditions, sodium concentra-tions are higher in the extracellular fluid, and potassium con-centrations are higher inside the cells. To maintain theseproportions, the active transport mechanism (the sodium-potassium pump) is activated, moving sodium from the cellsand potassium into the cells.

Regulating Body FluidsIn a healthy person, the volumes and chemical composition ofthe fluid compartments stay within narrow safe limits. Nor-mally fluid intake and fluid loss are balanced. Illness can upsetthis balance so that the body has too little or too much fluid.

Fluid IntakeDuring periods of moderate activity at moderate temperature, theaverage adult drinks about 1,500 mL per day but needs 2,500 mLper day, an additional 1,000 mL. This added volume is acquiredfrom foods and from the oxidation of these foods during metabolicprocesses. Interestingly, the water content of food is relativelylarge, contributing about 750 mL per day. The water content offresh vegetables is approximately 90%, of fresh fruits about 85%,and of lean meats around 60%.

Water as a by-product of food metabolism accounts for mostof the remaining fluid volume required. This quantity is approx-imately 200 mL per day for the average adult. See Table 52–1.

The thirst mechanism is the primary regulator of fluid intake.The thirst center is located in the hypothalamus of the brain. Anumber of stimuli trigger this center, including the osmoticpressure of body fluids, vascular volume, and angiotensin (ahormone released in response to decreased blood flow to thekidneys). For example, a long-distance runner loses significantamounts of water through perspiration and rapid breathing dur-ing a race, increasing the concentration of solutes and the os-motic pressure of body fluids. This increased osmotic pressurestimulates the thirst center, causing the runner to experience thesensation of thirst and the desire to drink to replace lost fluids.

Thirst is normally relieved immediately after drinking asmall amount of fluid, even before it is absorbed from the gas-trointestinal tract. However, this relief is only temporary, andthe thirst returns in about 15 minutes. The thirst is again tem-porarily relieved after the ingested fluid distends the upper gas-trointestinal tract. These mechanisms protect the individualfrom drinking too much, because it takes from 30 minutes to 1hour for the fluid to be absorbed and distributed throughout thebody. See Figure 52-7 ■.

Fluid OutputFluid losses from the body counterbalance the adult’s 2,500-mLaverage daily intake of fluid, as shown in Table 52–2. There arefour routes of fluid output:

1. Urine2. Insensible loss through the skin as perspiration and through

the lungs as water vapor in the expired air3. Noticeable loss through the skin4. Loss through the intestines in feces

URINE. Urine formed by the kidneys and excreted from the uri-nary bladder is the major avenue of fluid output. Normal urineoutput for an adult is 1,400 to 1,500 mL per 24 hours, or at least0.5 mL per kilogram per hour. In healthy people, urine outputmay vary noticeably from day to day. Urine volume automati-cally increases as fluid intake increases. If fluid loss through per-spiration is large, however, urine volume decreases to maintainfluid balance in the body.

INSENSIBLE LOSSES. Insensible fluid loss occurs through theskin and lungs. It is called insensible because it is usually not no-ticeable and cannot be measured. Insensible fluid loss through

TABLE 52–1 Average Daily Fluid Intake for an AdultSOURCE AMOUNT (ML)Oral fluids 1,200 to 1,500Water in foods 1,000Water as by-product of 200food metabolismTotal 2,400 to 2,700

Med

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nk

Filtr

atio

n Pr

essu

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atio

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the skin occurs in two ways. Water is lost through diffusion andthrough perspiration (which is noticeable but not measurable).Water losses through diffusion are not noticeable but normallyaccount for 300 to 400 mL per day. This loss can be significantlyincreased if the protective layer of the skin is lost as with burnsor large abrasions. Perspiration varies depending on factors suchas environmental temperature and metabolic activity. Fever andexercise increase metabolic activity and heat production, therebyincreasing fluid losses through the skin.

Another type of insensible loss is the water in exhaled air. Inan adult, this is normally 300 to 400 mL per day. When respira-tory rate accelerates, for example, due to exercise or an elevatedbody temperature, this loss can increase.

FECES. The chyme that passes from the small intestine into thelarge intestine contains water and electrolytes. The volume ofchyme entering the large intestine in an adult is normally about1,500 mL per day. Of this amount, all but about 100 mL is reab-sorbed in the proximal half of the large intestine.

Certain fluid losses are required to maintain normal bodyfunction. These are known as obligatory losses. Approximately500 mL of fluid must be excreted through the kidneys of anadult each day to eliminate metabolic waste products from thebody. Water lost through respirations, through the skin, and infeces also are obligatory losses, necessary for temperature reg-ulation and elimination of waste products. The total of all theselosses is approximately 1,300 mL per day.

Maintaining HomeostasisThe volume and composition of body fluids is regulated throughseveral homeostatic mechanisms.Anumber of body systems con-tribute to this regulation, including the kidneys, the endocrine sys-tem, the cardiovascular system, the lungs, and the gastrointestinalsystem. Hormones such as antidiuretic hormone (ADH; alsoknown as arginine vasopressin or AVP), the renin-angiotensin-aldosterone system, and atrial natriuretic factor are involved, asare mechanisms to monitor and maintain vascular volume.

KIDNEYS. The kidneys are the primary regulator of body fluidsand electrolyte balance. They regulate the volume and osmolal-ity of extracellular fluids by regulating water and electrolyte ex-cretion. The kidneys adjust the reabsorption of water fromplasma filtrate and ultimately the amount excreted as urine. Al-though 135 to 180 L of plasma per day is normally filtered in anadult, only about 1.5 L of urine is excreted. Electrolyte balanceis maintained by selective retention and excretion by the kid-neys. The kidneys also play a significant role in acid–base regu-lation, excreting hydrogen ion (H�) and retaining bicarbonate.

ANTIDIURETIC HORMONE. Antidiuretic hormone, which regu-lates water excretion from the kidney, is synthesized in the ante-rior portion of the hypothalamus and acts on the collecting ductsof the nephrons. When serum osmolality rises, ADH is produced,causing the collecting ducts to become more permeable to water.This increased permeability allows more water to be reabsorbedinto the blood. As more water is reabsorbed, urine output fallsand serum osmolality decreases because the water dilutes bodyfluids. Conversely, if serum osmolality decreases, ADH is sup-pressed, the collecting ducts become less permeable to water,and urine output increases. Excess water is excreted, and serumosmolality returns to normal. Other factors also affect the pro-duction and release of ADH, including blood volume, tempera-ture, pain, stress, and some drugs such as opiates, barbiturates,and nicotine. See Figure 52-8 ■.

RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM. Specializedreceptors in the juxtaglomerular cells of the kidney nephrons re-spond to changes in renal perfusion. This initiates the renin-angiotensin-aldosterone system. If blood flow or pressure to thekidney decreases, renin is released. Renin causes the conversionof angiotensinogen to angiotensin I, which is then converted toangiotensin II by angiotensin-converting enzyme. Angiotensin II

Increased volumeof extracellular fluid

and

and

Decreased volumeof extracellular fluid

Decreased osmolalityof extracellular fluid

Stimulates osmoreceptorsin hypothalamic

thirst center

Decreased saliva secretion

Water absorbed fromgastrointestinal tract

Dry mouth

Increased osmolalityof extracellular fluid

Sensation of thirst:person seeks a drink

Figure 52-7 ■ Factors stimulating water intake through the thirstmechanism.From Lemone, Priscilla; Burke, Karen M., Medical Surgical Nursing: Critical Thinking inClient Care, 3rd ed © 2004. Reproduced with permission of Pearson Education, Inc.,Upper Saddle River, New Jersey.

TABLE 52–2 Average Daily Fluid Output for an AdultROUTE AMOUNT (ML)Urine 1,400 to 1,500Insensible losses

Lungs 350 to 400Skin 350 to 400

Sweat 100Feces 100 to 200

Total 2,300 to 2,600

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acts directly on the nephrons to promote sodium and water reten-tion. In addition, it stimulates the release of aldosterone from the adrenal cortex. Aldosterone also promotes sodium retentionin the distal nephron. The net effect of the renin-angiotensin-aldosterone system is to restore blood volume (and renal perfu-sion) through sodium and water retention.

ATRIAL NATRIURETIC FACTOR. Atrial natriuretic factor (ANF)is released from cells in the atrium of the heart in response to ex-cess blood volume and stretching of the atrial walls. Acting onthe nephrons, ANF promotes sodium wasting and acts as a po-tent diuretic, thus reducing vascular volume. ANF also inhibitsthirst, reducing fluid intake.

Regulating ElectrolytesElectrolytes, charged ions capable of conducting electricity, arepresent in all body fluids and fluid compartments. Just as main-taining the fluid balance is vital to normal body function, so is

maintaining electrolyte balance. Although the concentration ofspecific electrolytes differs between fluid compartments, a bal-ance of cations (positively charged ions) and anions (negativelycharged ions) always exists. Electrolytes are important for

■ Maintaining fluid balance.■ Contributing to acid–base regulation.■ Facilitating enzyme reactions.■ Transmitting neuromuscular reactions.

Most electrolytes enter the body through dietary intake andare excreted in the urine. Some electrolytes, such as sodium andchloride, are not stored by the body and must be consumed dailyto maintain normal levels. Potassium and calcium, on the otherhand, are stored in the cells and bone, respectively. When serumlevels drop, ions can shift out of the storage “pool” into theblood to maintain adequate serum levels for normal function-ing. The regulatory mechanisms and functions of the majorelectrolytes are summarized in Table 52–3.

Urine output ↓Serum/blood osmolality ↓ as the water dilutes body fluids

Osmoreceptors inhypothalamus

stimulate posteriorpituitary to secrete ADH

ADH increasesdistal tubulepermeability

↑ Reabsorptionof H2O

into blood

↑ blood osmolality

Urine output ↑Serum osmolality returns to normal

ADH is suppressed

ADH causes distaltubules to becomeless permeableto water

↓ Reabsorptionof H2O

into blood

↓ blood osmolality

Figure 52-8 ■ Antidiuretic hormone (ADH) regulates water excretion from the kidneys.

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Sodium (Na�)Sodium is the most abundant cation in extracellular fluid and amajor contributor to serum osmolality. Normal serum sodiumlevels are 135 to 145 mEq/L. Sodium functions largely in con-trolling and regulating water balance. When sodium is reab-sorbed from the kidney tubules, chloride and water arereabsorbed with it, thus maintaining ECF volume. Sodium isfound in many foods, such as bacon, ham, processed cheese,and table salt.

Potassium (K�)Potassium is the major cation in intracellular fluids, with onlya small amount found in plasma and interstitial fluid. ICF lev-els of potassium are usually 125 to 140 mEq/L while normalserum potassium levels are 3.5 to 5.0 mEq/L. The ratio of in-tracellular to extracellular potassium must be maintained forneuromuscular response to stimuli. Potassium is a vital elec-trolyte for skeletal, cardiac, and smooth muscle activity. It isinvolved in maintaining acid–base balance as well, and it con-tributes to intracellular enzyme reactions. Potassium must beingested daily because the body can’t conserve it. Many fruitsand vegetables, meat, fish, and other foods contain potassium(see Box 52–1).

Calcium (Ca2�)The vast majority, 99%, of calcium in the body is in the skele-tal system, with a relatively small amount in extracellular fluid.Although this calcium outside the bones and teeth amounts toonly about 1% of the total calcium in the body, it is vital in reg-ulating muscle contraction and relaxation, neuromuscular func-tion, and cardiac function. ECF calcium is regulated by acomplex interaction of parathyroid hormone, calcitonin, andcalcitriol, a metabolite of vitamin D. When calcium levels in the

TABLE 52–3 Regulation and Functions of ElectrolytesELECTROLYTE REGULATION FUNCTIONSodium (Na�)

Potassium (K�)

Calcium (Ca2�)

Magnesium (Mg2�)

Chloride (Cl�)

Phosphate (PO4�)

Bicarbonate (HCO3�)

■ Regulating ECF volume and distribution■ Maintaining blood volume■ Transmitting nerve impulses and contracting muscles■ Maintaining ICF osmolality■ Transmitting nerve and other electrical impulses■ Regulating cardiac impulse transmission and muscle

contraction■ Skeletal and smooth muscle function■ Regulating acid–base balance■ Forming bones and teeth■ Transmitting nerve impulses■ Regulating muscle contractions■ Maintaining cardiac pacemaker (automaticity)■ Blood clotting■ Activating enzymes such as pancreatic lipase and

phospholipase■ Intracellular metabolism■ Operating sodium-potassium pump■ Relaxing muscle contractions■ Transmitting nerve impulses■ Regulating cardiac function■ HCl production■ Regulating ECF balance and vascular volume■ Regulating acid–base balance■ Buffer in oxygen–carbon dioxide exchange in RBCs■ Forming bones and teeth■ Metabolizing carbohydrate, protein, and fat■ Cellular metabolism; producing ATP and DNA■ Muscle, nerve, and RBC function■ Regulating acid–base balance■ Regulating calcium levels■ Major body buffer involved in acid–base regulation

■ Renal reabsorption or excretion■ Aldosterone increases Na� reabsorption in collecting

duct of nephrons■ Renal excretion and conservation■ Aldosterone increases K� excretion■ Movement into and out of cells■ Insulin helps move K� into cells; tissue damage and

acidosis shift K� out of cells into ECF

■ Redistribution between bones and ECF■ Parathyroid hormone and calcitriol increase serum

Ca2� levels; calcitonin decreases serum levels

■ Conservation and excretion by kidneys■ Intestinal absorption increased by vitamin D and

parathyroid hormone

■ Excreted and reabsorbed along with sodium in thekidneys

■ Aldosterone increases chloride reabsorption withsodium

■ Excretion and reabsorption by the kidneys■ Parathyroid hormone decreases serum levels by

increasing renal excretion■ Reciprocal relationship with calcium: increasing serum

calcium levels decrease phosphate levels; decreasingserum calcium increases phosphate

■ Excretion and reabsorption by the kidneys■ Regeneration by kidneys

BOX 52–1 Potassium-Rich Foods

VEGETABLESAvocadoRaw carrotBaked potatoRaw tomatoSpinach

MEATS AND FISHBeefCodPorkVeal

FRUITSDried fruits (e.g., raisins and dates)BananaApricotCantaloupeOrange

BEVERAGESMilkOrange juiceApricot nectar

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ECF fall, parathyroid hormone and calcitriol cause calcium tobe released from bones into ECF and increase the absorption ofcalcium in the intestines, thus raising serum calcium levels.Conversely, calcitonin stimulates the deposition of calcium inbone, reducing the concentration of calcium ions in the blood.

With aging, the intestines absorb calcium less effectively andmore calcium is excreted via the kidneys. Calcium shifts out ofthe bone to replace these ECF losses, increasing the risk of os-teoporosis and fractures of the wrists, vertebrae, and hips. Lackof weight-bearing exercise (which helps keep calcium in thebones) and a vitamin D deficiency because of inadequate expo-sure to sunlight contribute to this risk.

Milk and milk products are the richest sources of calcium,with other foods such as dark green leafy vegetables and cannedsalmon containing smaller amounts. Many clients benefit fromcalcium supplements.

Serum calcium levels are often reported in two ways, basedupon the way it is circulating in the plasma. Approximately 50%of serum calcium circulates in a free, ionized, or unbound form.The other 50% circulates in the plasma bound to either plasmaproteins or other nonprotein ions. The normal total serum cal-cium levels, which range from 8.5 to 10.5 mg/dL, represent bothbound and unbound calcium. The normal ionized serum calcium,which ranges from 4.0 to 5.0 mg/dL, represents calcium circulat-ing in the plasma in free, or unbound, form (Hayes, 2004).

Magnesium (Mg2�)Magnesium is primarily found in the skeleton and in intracellu-lar fluid. It is the second most abundant intracellular cation withnormal serum levels of 1.5 to 2.5 mEq/L. It is important for in-tracellular metabolism, being particularly involved in the pro-duction and use of ATP. Magnesium also is necessary for proteinand DNA synthesis within the cells. Only about 1% of thebody’s magnesium is in ECF; here it is involved in regulatingneuromuscular and cardiac function. Maintaining and ensuringadequate magnesium levels is an important part of care ofclients with cardiac disorders. Cereal grains, nuts, dried fruit,legumes, and green leafy vegetables are good sources of mag-nesium in the diet, as are dairy products, meat, and fish.

Chloride (Cl�)Chloride is the major anion of ECF, and normal serum levels are95 to 108 mEq/L. Chloride functions with sodium to regulateserum osmolality and blood volume. The concentration of chlo-ride in ECF is regulated secondarily to sodium; when sodium isreabsorbed in the kidney, chloride usually follows. Chloride is amajor component of gastric juice as hydrochloric acid (HCl)and is involved in regulating acid–base balance. It also acts as abuffer in the exchange of oxygen and carbon dioxide in RBCs.Chloride is found in the same foods as sodium.

Phosphate PO4�

Phosphate is the major anion of intracellular fluids. It also isfound in ECF, bone, skeletal muscle, and nerve tissue. Normalserum levels of phospate in adults range from 2.5 to 4.5 mg/dL.Children have much higher phosphate levels than adults, with

that of a newborn nearly twice that of an adult. Higher levels ofgrowth hormone and a faster rate of skeletal growth probablyaccount for this difference. Phosphate is involved in manychemical actions of the cell; it is essential for functioning ofmuscles, nerves, and red blood cells. It is also involved in themetabolism of protein, fat, and carbohydrate. Phosphate is ab-sorbed from the intestine and is found in many foods such asmeat, fish, poultry, milk products, and legumes.

Bicarbonate HCO3�

Bicarbonate is present in both intracellular and extracellular flu-ids. Its primary function is regulating acid–base balance as anessential component of the carbonic acid–bicarbonate bufferingsystem. Extracellular bicarbonate levels are regulated by thekidneys: Bicarbonate is excreted when too much is present; ifmore is needed, the kidneys both regenerate and reabsorb bicar-bonate ions. Unlike other electrolytes that must be consumed inthe diet, adequate amounts of bicarbonate are produced throughmetabolic processes to meet the body’s needs.

ACID–BASE BALANCEAn important part of regulating the chemical balance or home-ostasis of body fluids is regulating their acidity or alkalinity. Anacid is a substance that releases hydrogen ions (H�) in solution.Strong acids such as hydrochloric acid release all or nearly alltheir hydrogen ions; weak acids like carbonic acid release somehydrogen ions. Bases or alkalis have a low hydrogen ion con-centration and can accept hydrogen ions in solution. The rela-tive acidity or alkalinity of a solution is measured as pH. The pHreflects the hydrogen ion concentration of the solution: Thehigher the hydrogen ion concentration (and the more acidic thesolution), the lower the pH. Water has a pH of 7 and is neutral;that is, it is neither acidic in nature nor is it alkaline. Solutionswith a pH lower than 7 are acidic; those with a pH higher than7 are alkaline. The pH scale is logarithmic: A solution with a pHof 5 is 10 times more acidic than one with a pH of 6.

Regulation of Acid–Base BalanceBody fluids are maintained within a narrow range that is slightlyalkaline. The normal pH of arterial blood is between 7.35 and7.45 (Figure 52-9 ■). Acids are continually produced during me-

Death Acidosis Normal Alkalosis Death

6.8 7.35 7.45 7.8

1 7 14Alkalinesolution(low H+)

Neutral

pH scale

pH

Acidicsolution

(high H+)

Figure 52-9 ■ Body fluids are normally slightly alkaline, between a pHof 7.35 and 7.45.

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tabolism. Several body systems, including buffers, the respira-tory system, and the renal system, are actively involved in main-taining the narrow pH range necessary for optimal function.Buffers help maintain acid–base balance by neutralizing excessacids or bases. The lungs and the kidneys help maintain a nor-mal pH by either excreting or retaining acids and bases.

BuffersBuffers prevent excessive changes in pH by removing or releas-ing hydrogen ions. If excess hydrogen ion is present in body flu-ids, buffers bind with the hydrogen ion, minimizing the changein pH. When body fluids become too alkaline, buffers can re-lease hydrogen ion, again minimizing the change in pH. The ac-tion of a buffer is immediate, but limited in its capacity tomaintain or restore normal acid–base balance.

The major buffer system in extracellular fluids is the bicarbon-ate (HCO3

�) and carbonic acid (H2CO3) system. When a strongacid such as hydrochloric acid (HCl) is added, it combines with bi-carbonate and the pH drops only slightly. A strong base such assodium hydroxide combines with carbonic acid, the weak acid ofthe buffer pair, and the pH remains within the narrow range of nor-mal. The amounts of bicarbonate and carbonic acid in the bodyvary; however, as long as a ratio of 20 parts of bicarbonate to 1 partof carbonic acid is maintained, the pH remains within its normalrange of 7.35 to 7.45 (Figure 52-10 ■). Adding a strong acid toECF can change this ratio as bicarbonate is depleted in neutraliz-ing the acid. When this happens, the pH drops, and the client hasa condition called acidosis. The ratio can also be upset by addinga strong base to ECF, depleting carbonic acid as it combines withthe base. In this case the pH rises and the client has alkalosis.

In addition to the bicarbonate–carbonic acid buffer system,plasma proteins, hemoglobin, and phosphates also function asbuffers in body fluids.

Respiratory RegulationThe lungs help regulate acid–base balance by eliminating or re-taining carbon dioxide (CO2), a potential acid. Combined withwater, carbon dioxide forms carbonic acid (CO2 � H2O →H2CO3). This chemical reaction is reversible; carbonic acid

breaks down into carbon dioxide and water. Working togetherwith the bicarbonate–carbonic acid buffer system, the lungs reg-ulate acid–base balance and pH by altering the rate and depth ofrespirations. The response of the respiratory system to changesin pH is rapid, occurring within minutes.

Carbon dioxide is a powerful stimulator of the respiratorycenter. When blood levels of carbonic acid and carbon dioxiderise, the respiratory center is stimulated and the rate and depthof respirations increase. Carbon dioxide is exhaled, and car-bonic acid levels fall. By contrast, when bicarbonate levels areexcessive, the rate and depth of respirations are reduced. Thiscauses carbon dioxide to be retained, carbonic acid levels torise, and the excess bicarbonate to be neutralized.

Carbon dioxide levels in the blood are measured as thePCO2, or partial pressure of the dissolved gas in the blood.PCO2 refers to the pressure of carbon dioxide in venous blood.PaCO2 refers to the pressure of carbon dioxide in arterial blood.The normal PaCO2 is 35 to 45 mm Hg.

Renal RegulationAlthough buffers and the respiratory system can compensate forchanges in pH, the kidneys are the ultimate long-term regulatorof acid–base balance. They are slower to respond to changes, re-quiring hours to days to correct imbalances, but their responseis more permanent and selective than that of the other systems(Yucha, 2004).

The kidneys maintain acid–base balance by selectively ex-creting or conserving bicarbonate and hydrogen ions. When ex-cess hydrogen ion is present and the pH falls (acidosis), thekidneys reabsorb and regenerate bicarbonate and excrete hydro-gen ion. In the case of alkalosis and a high pH, excess bicarbon-ate is excreted and hydrogen ion is retained. The normal serumbicarbonate level is 22 to 26 mEq/L.

The relationship of the respiratory and renal regulation ofacid–base balance is further explained in Box 52–2.

1 partcarbonicacid or

1.2 mEq/L

20 partsbicarbonate

or24 mEq/L

6.8 7.35 7.45 7.8

NormalAcidosisDeath DeathAlkalosis

Figure 52-10 ■ Carbonic acid–bicarbonate ratio and pH.

BOX 52–2 Physiological Regulation of Acid–Base Balance

Lungs KidneysCO2 � H2O ↔ H2CO3 ↔ H � HCO3

Carbon dioxide Hydrogen� Carbonic acid �

water bicarbonate

The lungs and kidneys are the two major systems that are working ona continuous basis to help regulate the acid–base balance in the body.In the biochemical reactions above, the processes are all reversible andgo back and forth as the body’s needs change. The lungs can work veryquickly and do their part by either retaining or getting rid of carbon diox-ide by changing the rate and depth of respirations. The kidneys workmuch more slowly; they may take hours to days to regulate the bal-ance by either excreting or conserving hydrogen and bicarbonate ions.Under normal conditions, the two systems work together to maintainhomeostasis.

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FACTORS AFFECTING BODY FLUID,ELECTROLYTES, AND ACID–BASE BALANCEThe ability of the body to adjust fluids, electrolytes, andacid–base balance is influenced by age, gender and body size,environmental temperature, and lifestyle.

AgeInfants and growing children have much greater fluid turnoverthan adults because their higher metabolic rate increases fluidloss. Infants lose more fluid through the kidneys because imma-ture kidneys are less able to conserve water than adult kidneys.In addition, infants’ respirations are more rapid and the bodysurface area is proportionately greater than that of adults, in-creasing insensible fluid losses. The more rapid turnover offluid plus the losses produced by disease can create critical fluidimbalances in children much more rapidly than in adults.

In elderly people, the normal aging process may affect fluidbalance. The thirst response often is blunted. Antidiuretic hor-mone levels remain normal or may even be elevated, but thenephrons become less able to conserve water in response toADH. Increased levels of atrial natriuretic factor seen in olderadults may also contribute to this impaired ability to conservewater. These normal changes of aging increase the risk of dehy-dration. When combined with the increased likelihood of heartdiseases, impaired renal function, and multiple drug regimens,the older adult’s risk for fluid and electrolyte imbalance is sig-nificant. Additionally, it is important to consider that the older

adult has thinner, more fragile skin and veins, which can makean intravenous insertion more difficult.

Gender and Body SizeTotal body water also is affected by gender and body size. Be-cause fat cells contain little or no water, and lean tissue has ahigh water content, people with a higher percentage of body fathave less body fluid. Women have proportionately more bodyfat and less body water than men. Water accounts for approxi-mately 60% of an adult man’s weight, but only 52% for an adultwoman. In an obese individual this may be even less, with wa-ter responsible for only 30% to 40% of the person’s weight.

Environmental TemperaturePeople with an illness and those participating in strenuous ac-tivity are at risk for fluid and electrolyte imbalances when theenvironmental temperature is high. Fluid losses through sweat-ing are increased in hot environments as the body attempts todissipate heat. These losses are even greater in people who havenot been acclimatized to the environment.

Both salt and water are lost through sweating. When onlywater is replaced, salt depletion is a risk. The person who is saltdepleted may experience fatigue, weakness, headache, and gas-trointestinal symptoms such as anorexia and nausea. The risk ofadverse effects is even greater if lost water is not replaced. Bodytemperature rises, and the person is at risk for heat exhaustionor heatstroke. Heatstroke may occur in older adults or ill peopleduring prolonged periods of heat; it can also affect athletes and

LIFESPAN CONSIDERATIONS Fluid and Electrolyte Imbalance

INFANTS AND CHILDREN

Infants are at high risk for fluid and electrolyte imbalance because

■ Their immature kidneys cannot concentrate urine.■ They have a rapid respiratory rate and proportionately larger body

surface area than adults, leading to greater insensate loss throughthe skin and respirations.

■ They cannot express thirst, nor actively seek fluids.

Vomiting and/or diarrhea in infants and young children can leadquickly to electrolyte imbalance. Oral rehydration therapy (ORT) (e.g.,electrolyte solutions such as Pedialyte) should be used to restore fluidand electrolyte balance in mild to moderate dehydration (AmericanMedical Association et al., 2004). Prompt treatment with ORT can pre-vent the need for intravenous therapy and hospitalization (Spandor-fer, Alessandrini, Joffe, Localio, & Shaw, 2005). Even if the child isnauseated and vomiting, small sips of ORT can be helpful.

ELDERS

Certain changes related to aging place the elder at risk for seriousproblems with fluid and electrolyte imbalance, if homeostatic mecha-nisms are compromised. Some of the changes are

■ A decrease in thirst sensation.■ A decrease in ability of the kidneys to concentrate urine.■ A decrease in intracellular fluid and in total body water.■ A decrease in response to body hormones that help regulate fluid

and electrolytes.

Other factors that may influence fluid and electrolyte balance inelders are

■ Increased use of diuretics for hypertension and heart disease.■ Decreased intake of food and water, especially in elders with de-

mentia or who are dependent on others to feed them and offerthem fluids.

■ Preparations for certain diagnostic tests that have the client NPOfor long periods of time or cause diarrhea from laxative preps.

■ Clients with impaired renal function, such as elders with diabetes.■ Those having certain diagnostic procedures. (Dyes used for some

procedures, such as arteriograms and cardiac catheterizations,may cause further renal problems. Always see that the client is wellhydrated before, during, and after the procedure to help in dilutingand excreting the dye. If the client is NPO for the procedure, thenurse should check with the primary care provider to see if IV flu-ids are needed.)

■ Any condition that may tax the normal compensatory mecha-nisms, such as a fever, influenza, surgery, or heat exposure.

All of these conditions increase elders’ risk for fluid and electrolyteimbalance. The change can happen quickly and become serious in ashort time. Astute observations and quick actions by the nurse canhelp prevent serious consequences. A change in mental status maybe the first symptom of impairment and must be further evaluated todetermine the cause.

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laborers when their heat production exceeds the body’s abilityto dissipate heat.

Consuming adequate amounts of cool liquids, particularly dur-ing strenuous activity, reduces the risk of adverse effects fromheat. Balanced electrolyte solutions and carbohydrate-electrolytesolutions such as sports drinks are recommended because theyreplace both water and electrolytes lost through sweat.

LifestyleOther factors such as diet, exercise, and stress affect fluid, elec-trolyte, and acid–base balance.

The intake of fluids and electrolytes is affected by the diet.People with anorexia nervosa or bulimia are at risk for severefluid and electrolyte imbalances because of inadequate intake orpurging regimens (e.g., induced vomiting, use of diuretics andlaxatives). Seriously malnourished people have decreasedserum albumin levels, and may develop edema because the os-motic draw of fluid into the vascular compartment is reduced.When calorie intake is not adequate to meet the body’s needs,fat stores are broken down and fatty acids are released, increas-ing the risk of acidosis.

Regular weight-bearing physical exercise such as walking,running, or bicycling has a beneficial effect on calcium balance.The rate of bone loss that occurs in postmenopausal women andolder men is slowed with regular exercise, reducing the risk ofosteoporosis.

Stress can increase cellular metabolism, blood glucose con-centration, and catecholamine levels. In addition, stress can in-crease production of ADH, which in turn decreases urineproduction. The overall response of the body to stress is to in-crease the blood volume.

Other lifestyle factors can also affect fluid, electrolyte, andacid–base balance. Heavy alcohol consumption affects elec-trolyte balance, increasing the risk of low calcium, magnesium,and phosphate levels. The risk of acidosis associated withbreakdown of fat tissue also is greater in the person who drinkslarge amounts of alcohol.

DISTURBANCES IN FLUID VOLUME, ELECTROLYTE, AND ACID–BASE BALANCESA number of factors such as illness, trauma, surgery, and med-ications can affect the body’s ability to maintain fluid, elec-trolyte, and acid–base balance. The kidneys play a major role inmaintaining fluid, electrolyte, and acid–base balance, and renaldisease is a significant cause of imbalance. Clients who are con-fused or unable to communicate their needs are at risk for inad-equate fluid intake. Vomiting, diarrhea, or nasogastric suctioncan cause significant fluid losses. Tissue trauma, such as burns,causes fluid and electrolytes to be lost from damaged cells. De-creased blood flow to the kidneys due to impaired cardiac func-tion stimulates the renin-angiotensin-aldosterone system,causing sodium and water retention. Medications such as di-uretics or corticosteroids can result in abnormal losses of elec-trolytes and fluid loss or retention. Diseases such as diabetesmellitus or chronic obstructive lung disease may affect

acid–base balance. Diabetic ketoacidosis, cancer, and head in-jury may also lead to electrolyte imbalances.

Fluid ImbalancesFluid imbalances are of two basic types: isotonic and osmolar.Isotonic imbalances occur when water and electrolytes are lostor gained in equal proportions, so that the osmolality of bodyfluids remains constant. Osmolar imbalances involve the lossor gain of only water, so that the osmolality of the serum is al-tered. Thus four categories of fluid imbalances may occur: (a) an isotonic loss of water and electrolytes, (b) an isotonicgain of water and electrolytes, (c) a hyperosmolar loss of onlywater, and (d) a hypo-osmolar gain of only water. These are re-ferred to, respectively, as fluid volume deficit, fluid volumeexcess, dehydration (hyperosmolar imbalance), and overhy-dration (hypo-osmolar imbalance).

Fluid Volume DeficitIsotonic fluid volume deficit (FVD) occurs when the body losesboth water and electrolytes from the ECF in similar proportions.Thus, the decreased volume of fluid remains isotonic. In FVD,fluid is initially lost from the intravascular compartment, so itoften is called hypovolemia.

FVD generally occurs as a result of (a) abnormal lossesthrough the skin, gastrointestinal tract, or kidney; (b) de-creased intake of fluid; (c) bleeding; or (d) movement of fluidinto a third space. See the section on third space syndromethat follows.

For the risk factors and clinical signs related to fluid volumedeficit, see Table 52–4.

THIRD SPACE SYNDROME. In third space syndrome, fluidshifts from the vascular space into an area where it is not readilyaccessible as extracellular fluid. This fluid remains in the bodybut is essentially unavailable for use, causing an isotonic fluidvolume deficit. Fluid may be sequestered in the bowel, in the in-terstitial space as edema, in inflamed tissue, or in potentialspaces such as the peritoneal or pleural cavities.

The client with third space syndrome has an isotonic fluiddeficit but may not manifest apparent fluid loss or weight loss.Careful nursing assessment is vital to effectively identify and in-tervene for clients experiencing third-spacing. Because the fluidshifts back into the vascular compartment after time, assessmentfor manifestations of fluid volume excess or hypervolemia isalso vital.

Fluid Volume ExcessFluid volume excess (FVE) occurs when the body retains bothwater and sodium in similar proportions to normal ECF. This iscommonly referred to as hypervolemia (increased blood vol-ume). FVE is always secondary to an increase in the total bodysodium content, which leads to an increase in total body water.Because both water and sodium are retained, the serum sodiumconcentration remains essentially normal and the excess vol-ume of fluid is isotonic. Specific causes of FVE include (a) ex-cessive intake of sodium chloride; (b) administeringsodium-containing infusions too rapidly, particularly to clients

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with impaired regulatory mechanisms; and (c) diseaseprocesses that alter regulatory mechanisms, such as heart fail-ure, renal failure, cirrhosis of the liver, and Cushing’s syndrome.

The risk factors and clinical manifestations for FVE are sum-marized in Table 52–5.

EDEMA. In fluid volume excess, both intravascular and intersti-tial spaces have an increased water and sodium content. Excessinterstitial fluid is known as edema. Edema typically is most ap-parent in areas where the tissue pressure is low, such as aroundthe eyes, and in dependent tissues (known as dependent edema),where hydrostatic capillary pressure is high.

Edema can be caused by several different mechanisms. Thethree main mechanisms are increased capillary hydrostatic pres-sure, decreased plasma oncotic pressure, and increased capil-lary permeability. It may be due to FVE that increases capillary

hydrostatic pressures, pushing fluid into the interstitial tissues.This type of edema is often seen in dependent tissues such as thefeet, ankles, and sacrum because of the effects of gravity. Lowlevels of plasma proteins from malnutrition or liver or kidneydiseases can reduce the plasma oncotic pressure so that fluid isnot drawn into the capillaries from interstitial tissues, causingedema. With tissue trauma and some disorders such as allergicreactions, capillaries become more permeable, allowing fluid toescape into interstitial tissues. Obstructed lymph flow impairsthe movement of fluid from interstitial tissues back into the vas-cular compartment, resulting in edema.

Pitting edema is edema that leaves a small depression or pitafter finger pressure is applied to the swollen area. The pit iscaused by movement of fluid to adjacent tissue, away from thepoint of pressure (Figure 52-11 ■). Within 10 to 30 seconds thepit normally disappears.

TABLE 52–4 Isotonic Fluid Volume DeficitRISK FACTORS CLINICAL MANIFESTATIONS NURSING INTERVENTIONSLoss of water and electrolytes from■ Vomiting■ Diarrhea■ Excessive sweating■ Polyuria■ Fever■ Nasogastric suction■ Abnormal drainage or wound lossesInsufficient intake due to■ Anorexia■ Nausea■ Inability to access fluids■ Impaired swallowing■ Confusion, depression

Complaints of weakness and thirst Weight loss■ 2% loss � mild FVD■ 5% loss � moderate■ 8% loss � severeFluid intake less than outputDecreased tissue turgorDry mucous membranes, sunken eyeballs,decreased tearingSubnormal temperatureWeak, rapid pulseDecreased blood pressurePostural (orthostatic) hypotension (significantdrop in BP when moving from lying to sittingor standing position)Flat neck veins; decreased capillary refillDecreased central venous pressureDecreased urine volume (<30 mL/h)Increased specific gravity of urine (>1.030)Increased hematocritIncreased blood urea nitrogen (BUN)

Assess for clinical manifestations of FVD.Monitor weight and vital signs, includingtemperature.Assess tissue turgor.Monitor fluid intake and output.Monitor laboratory findings.Administer oral and intravenous fluids asindicated.Provide frequent mouth care.Implement measures to prevent skinbreakdown.Provide for safety, e.g., provide assistance fora client rising from bed.

TABLE 52–5 Isotonic Fluid Volume ExcessRISK FACTORS CLINICAL MANIFESTATIONS NURSING INTERVENTIONS

Weight gain■ 2% gain � mild FVE■ 5% gain � moderate■ 8% gain � severeFluid intake greater than outputFull, bounding pulse; tachycardiaIncreased blood pressure and central venouspressureDistended neck and peripheral veins; slowvein emptyingMoist crackles (rales) in lungs; dyspnea,shortness of breathMental confusion

Excess intake of sodium-containingintravenous fluidsExcess ingestion of sodium in diet ormedications (e.g., sodium bicarbonateantacids such as Alka-Seltzer or hypertonicenema solutions such as Fleet’s)Impaired fluid balance regulation relatedto■ Heart failure■ Renal failure■ Cirrhosis of the liver

Assess for clinical manifestations of FVE.Monitor weight and vital signs.Assess for edema.Assess breath sounds.Monitor fluid intake and output.Monitor laboratory findings.Place in Fowler’s position.Administer diuretics as ordered.Restrict fluid intake as indicated.Restrict dietary sodium as ordered.Implement measures to prevent skinbreakdown.

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DehydrationDehydration, or hyperosmolar imbalance, occurs when water islost from the body leaving the client with excess sodium. Be-cause water is lost while electrolytes, particularly sodium, areretained, the serum osmolality and serum sodium levels in-crease. Water is drawn into the vascular compartment from theinterstitial space and cells, resulting in cellular dehydration.Older adults are at particular risk for dehydration because of de-creased thirst sensation. This type of water deficit also can af-fect clients who are hyperventilating or have prolonged fever orare in diabetic ketoacidosis and those receiving enteral feedingswith insufficient water intake.

OverhydrationOverhydration, also known as hypo-osmolar imbalance or waterexcess, occurs when water is gained in excess of electrolytes, re-sulting in low serum osmolality and low serum sodium levels.Water is drawn into the cells, causing them to swell. In the brainthis can lead to cerebral edema and impaired neurologic func-tion. Water intoxication often occurs when both fluid and elec-trolytes are lost, for example, through excessive sweating, butonly water is replaced. It can also result from the syndrome ofinappropriate antidiuretic hormone (SIADH), a disorder that canoccur with some malignant tumors, AIDS, head injury, or ad-ministration of certain drugs such as barbiturates or anesthetics.

Figure 52-11 ■ Evaluation of edema. A, Palpate for edema over the tibia as shown here and behind the medial malleolus, and over the dorsum ofeach foot. B, Four-point scale for grading edema.

2mm

1+ Barely detectable

4mm

2+ 2 to 4 mm

6mm

3+ 5 to 7 mm

12mm4+ More than 7 mm

BA

DRUG CAPSULE Diuretic Agent furosemide (Lasix)

THE CLIENT WITH FLUID VOLUME EXCESS

Furosemide inhibits sodium and chloride reabsorption in the loop of Henle and the distal renal tubule. This results in significant diuresis,with renal excretion of water, sodium chloride, magnesium, hydrogen, and calcium.

Furosemide is commonly used for the clinical management of edema secondary to heart failure, treatment of hypertension, and treat-ment of hepatic or renal disease. Therapeutic effects include diuresis and lowering of blood pressure.

NURSING RESPONSIBILITIES

■ Assess the client’s fluid status regularly. Assessment should in-clude daily weights, close monitoring of intake and output, skinturgor, edema, lung sounds, and mucous membranes.

■ Monitor the client’s potassium levels. Furosemide is a loop diuretic which excretes potassium and may result in hypokalemia.

■ Administer in the morning to avoid increased urination duringhours of sleep.

■ If the client is also taking digitalis glycosides, he or she should beassessed for anorexia, nausea, vomiting, muscle cramps, pares-thesia, and confusion. The potassium-depleting effect offurosemide places the client at increased risk for digitalis toxicity.

CLIENT AND FAMILY TEACHING

■ Medication should be taken exactly as directed. If you miss adose, take it as soon as possible; however, if a day has beenmissed, do not double the dose the next day.

■ Weigh on a daily basis and report weight gain or loss of morethan 3 lb in 1 day to your primary care provider.

■ Contact your primary care provider immediately if you begin toexperience muscle weakness, cramps, nausea, dizziness,numbness, or tingling of the extremities.

■ Some form of potassium supplementation will be needed. Theprimary care provider may order oral potassium supplements foryou; if not, you will need to consume a diet high in potassium.

■ Make position changes slowly in order to minimize dizzinessfrom orthostatic hypotension.

Note: Prior to administering any medication, review all aspects with a current drug handbook or other reliable source.

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Electrolyte ImbalancesThe most common and most significant electrolyte imbalancesinvolve sodium, potassium, calcium, magnesium, chloride, andphosphate.

SodiumSodium (Na�), the most abundant cation in the extracellularfluid, not only moves into and out of the body but also moves incareful balance among the three fluid compartments. It is foundin most body secretions, for example, saliva, gastric and intes-tinal secretions, bile, and pancreatic fluid. Therefore, continu-ous excretion of any of these fluids, such as via intestinalsuction, can result in a sodium deficit. Because of its role in reg-ulating water balance, sodium imbalances usually are accompa-nied by water imbalance.

Hyponatremia is a sodium deficit, or serum sodium level ofless than 135 mEq/L, and is, in acute care settings, a commonelectrolyte imbalance. Because of sodium’s role in determiningthe osmolality of ECF, hyponatremia typically results in a lowserum osmolality. Water is drawn out of the vascular compart-ment into interstitial tissues and the cells (Figure 52-12 ■, A),causing the clinical manifestations associated with this disorder.As sodium levels decrease, the brain and nervous system are af-fected by cellular edema. Severe hyponatremia, serum levelsbelow 110 mEq/L, is a medical emergency and can lead to per-manent neurological damage (Astle, 2005).

Hypernatremia is excess sodium in ECF, or a serum sodiumof greater than 145 mEq/L. Because the osmotic pressure of ex-tracellular fluid is increased, fluid moves out of the cells into theECF (Figure 52-12 ■, B). As a result, the cells become dehy-drated. Like hyponatremia, the primary manifestations of hy-pernatremia are neurological in nature.

It is important to note that a person’s thirst mechanism pro-tects against hypernatremia. For example, when an individualbecomes thirsty, the body is stimulated to drink water whichhelps correct the hypernatremia. Clients at risk for hyperna-tremia are those who are unable to access water (e.g., uncon-scious, unable to request fluids such as infants or elders withdementia, or ill clients with an impaired thirst mechanism).

Table 52–6 lists risk factors and clinical signs for hypona-tremia and hypernatremia.

PotassiumAlthough the amount of potassium (K�) in extracellular fluid issmall, it is vital to normal neuromuscular and cardiac function.Normal renal function is important for maintenance of potas-sium balance as 80% of potassium is excreted by the kidneys.Potassium must be replaced daily to maintain its balance. Nor-mally, potassium is replaced in food. See previous Box 52–1 onpage 1431 for a review of foods high in potassium.

Hypokalemia is a potassium deficit or a serum potassiumlevel of less than 3.5 mEq/L. Gastrointestinal losses of potas-sium through vomiting and gastric suction are common causesof hypokalemia, as are the use of potassium-wasting diuretics,such as thiazide diuretics or loop diuretics (e.g., furosemide).Symptoms of hypokalemia are usually mild until the level dropsbelow 3 mEq/L unless the decrease in potassium was rapid.When the decrease is gradual, the body compensates by shiftingpotassium from the intracellular environment into the serum.

Hyperkalemia is a potassium excess or a serum potassiumlevel greater than 5.0 mEq/L. Hyperkalemia is less commonthan hypokalemia and rarely occurs in clients with normal renalfunction. It is, however, more dangerous than hypokalemia andcan lead to cardiac arrest. As with hypokalemia, symptoms aremore severe and occur at lower levels when the increase inpotassium is abrupt. Table 52–6 lists risk factors and clinicalsigns for hypokalemia and hyperkalemia.

RESEARCH NOTE How Prevalent Is Chronic Dehydration in Elders?

Previous research has documented that dehydration is a problem inhospitalized elders, and low fluid intake has been documented to be aproblem in nursing home residents. The authors questioned whetherchronic dehydration is also a problem in elders living in the community.The researchers conducted a descriptive, retrospective study of 185 eld-ers ranging from 75 to 100 years old. This group of elders visited a hos-pital emergency department during a 1-month period of time.Dehydration was defined as a ratio of blood urea nitrogen to creatine(BUN:Cr) greater than 20:1. Forty-eight percent of the group were de-hydrated on admission to the emergency department. The elders froma residential facility were most likely to be dehydrated (65%); however,44% of the elders living in the community were dehydrated.

IMPLICATIONSThe results demonstrated that dehydration is a problem with both eld-ers living in the community as well as elders living in residential facili-ties. Prevention of dehydration is an important intervention for nursesworking with elders. Nursing interventions need to include talking withelders and their families about the dangers of dehydration and sug-gesting strategies to prevent dehydration.

Note: From “Unrecognized Chronic Dehydration in Older Adults. Examining Preva-lence Rate and Risk Factors,” by J. A. Bennett, V. Thomas, and B. Riegel, 2004,Journal of Gerontological Nursing, 30(1), pp. 22–28. Copyright © 2004 SLACK,Inc. Reprinted with permission.

H2O

H2O

H2O

Cell swells as wateris pulled in from ECF

Hyponatremia:Na+less than 135 mEq/L

A

Figure 52-12 ■ The extracellular sodium level affects cell size. A, Inhyponatremia, cells swell; B, in hypernatremia, cells shrink in size.

H2O

Cell shrinks as wateris pulled out into ECF

Hypernatremia:Na+greater than 145 mEq/L

B

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TABLE 52–6 Electrolyte ImbalancesRISK FACTORS CLINICAL MANIFESTATIONS NURSING INTERVENTIONS

Hyponatremia

Loss of sodium■ Gastrointestinal fluid loss■ Sweating■ Use of diuretics

Gain of water■ Hypotonic tube feedings■ Excessive drinking of water■ Excess IV D5W (dextrose in water)

administrationSyndrome of inappropriate ADH(SIADH)■ Head injury■ AIDS■ Malignant tumors

Hypernatremia

Loss of water■ Insensible water loss (hyperventilation

or fever)■ Diarrhea■ Water deprivationGain of sodium■ Parenteral administration of saline

solutions■ Hypertonic tube feedings without

adequate water■ Excessive use of table salt (1 tsp

contains 2,300 mg of sodium)Conditions such as■ Diabetes insipidus■ Heat stroke

Hypokalemia

Loss of potassium■ Vomiting and gastric suction■ Diarrhea■ Heavy perspiration■ Use of potassium-wasting drugs (e.g.,

diuretics)■ Poor intake of potassium (as with

debilitated clients, alcoholics, anorexianervosa)

■ Hyperaldosteronism

Hyperkalemia

Decreased potassium excretion■ Renal failure■ Hypoaldosteronism■ Potassium-conserving diureticsHigh potassium intake

Lethargy, confusion, apprehensionMuscle twitchingAbdominal crampsAnorexia, nausea, vomitingHeadacheSeizures, comaLaboratory findings:Serum sodium below 135 mEq/LSerum osmolality below 280 mOsm/kg

ThirstDry, sticky mucous membranesTongue red, dry, swollenWeakness

Severe hypernatremia:■ Fatigue, restlessness■ Decreasing level of consciousness■ Disorientation■ ConvulsionsLaboratory findings:Serum sodium above 145 mEq/LSerum osmolality above 300 mOsm/kg

Muscle weakness, leg crampsFatigue, lethargyAnorexia, nausea, vomitingDecreased bowel sounds, decreased bowelmotilityCardiac dysrhythmiasDepressed deep-tendon reflexesWeak, irregular pulsesLaboratory findings:Serum potassium below 3.5 mEq/LArterial blood gases (ABGs) may show alkalosis T wave flattening and ST segment depressionon ECG

Gastrointestinal hyperactivity, diarrheaIrritability, apathy, confusionCardiac dysrhythmias or arrestMuscle weakness, areflexia (absence ofreflexes)Decreased heart rate;Irregular pulse

Assess clinical manifestations.Monitor fluid intake and output.Monitor laboratory data (e.g., serum sodium).Assess client closely if administeringhypertonic saline solutions.Encourage food and fluid high in sodium ifpermitted (e.g., table salt, bacon, ham,processed cheese).Limit water intake as indicated.

Monitor fluid intake and output.Monitor behavior changes (e.g., restlessness,disorientation).Monitor laboratory findings (e.g., serumsodium).Encourage fluids as ordered.Monitor diet as ordered (e.g., restrict intake ofsalt and foods high in sodium).

Monitor heart rate and rhythm.Monitor clients receiving digitalis (e.g., digoxin)closely, because hypokalemia increases risk ofdigitalis toxicity.Administer oral potassium as ordered withfood or fluid to prevent gastric irritation.Administer IV potassium solutions at a rate nofaster than 10–20 mEq/h; never administerundiluted potassium intravenously. For clientsreceiving IV potassium, monitor for pain andinflammation at the injection site.Teach client about potassium-rich foods.Teach clients how to prevent excessive loss ofpotassium (e.g., through abuse of diureticsand laxatives).

Closely monitor cardiac status and ECG.Administer diuretics and other medicationssuch as glucose and insulin as ordered.Hold potassium supplements and K�

conserving diuretics.

continued on page 1440

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RISK FACTORS CLINICAL MANIFESTATIONS NURSING INTERVENTIONS

Hyperkalemia—continued

TABLE 52–6 Electrolyte Imbalances—continued

■ Excessive use of K� containing saltsubstitutes

■ Excessive or rapid IV infusion ofpotassium

■ Potassium shift out of the tissue cellsinto the plasma (e.g., infections, burns,acidosis)

Hypocalcemia

Surgical removal of the parathyroidglandsConditions such as ■ Hypoparathyroidism■ Acute pancreatitis■ Hyperphosphatemia■ Thyroid carcinoma

Inadequate vitamin D intake■ Malabsorption■ Hypomagnesemia■ Alkalosis■ Sepsis■ Alcohol abuse

Hypercalcemia

■ Prolonged immobilizationConditions such as■ Hyperparathyroidism■ Malignancy of the bone■ Paget’s disease

Hypomagnesemia

■ Excessive loss from the gastrointestinaltract (e.g., from nasogastric suction,diarrhea, fistula drainage)

■ Long-term use of certain drugs (e.g.,diuretics, aminoglycoside antibiotics)

Conditions such as■ Chronic alcoholism■ Pancreatitis■ Burns

Paresthesias and numbness in extremitiesLaboratory findings:Serum potassium above 5.0 mEq/LPeaked T wave, widened QRS on ECG

Numbness, tingling of the extremities andaround the mouthMuscle tremors, cramps; if severe can progressto tetany and convulsionsCardiac dysrhythmias; decreased cardiac outputPositive Trousseau’s and Chvostek’s signs (seeTable 52–8)Confusion, anxiety, possible psychosesHyperactive deep tendon reflexesLaboratory findings:Serum calcium less than 8.5 mg/dL or 4.5 mEq/L (total)Lengthened QT intervalsProlonged ST segments

Lethargy, weaknessDepressed deep-tendon reflexesBone painAnorexia, nausea, vomitingConstipationPolyuria, hypercalciuriaFlank pain secondary to urinary calculiDysrhythmias, possible heart blockLaboratory findings:Serum calcium greater than 10.5 mg/dL or 5.5 mEq/L (total)Shortened QT intervalsShortened ST segments

Neuromuscular irritability with tremorsIncreased reflexes, tremors, convulsionsPositive Chvostek’s and Trousseau’s signs (seeTable 52–8)

Tachycardia, elevated blood pressure,dysrhythmiasDisorientation and confusionVertigoAnorexia, dysphagiaRespiratory difficultiesLaboratory findings:Serum magnesium below 1.5 mEq/LProlonged PR intervals, widened QRScomplexes, prolonged QT intervals, depressedST segments, broad flattened T waves,prominent U waves

Monitor serum K� levels carefully; a rapid dropmay occur as potassium shifts into the cells.Teach clients to avoid foods high in potassiumand salt substitutes.

Closely monitor respiratory and cardiovascularstatus.Take precautions to protect a confused client.Administer oral or parenteral calciumsupplements as ordered. When administeringintravenously, closely monitor cardiac statusand ECG during infusion.Teach clients at high risk for osteoporosis about■ Dietary sources rich in calcium.■ Recommendation for 1,000–1,500 mg of

calcium per day.■ Calcium supplements.■ Regular exercise.■ Estrogen replacement therapy for

postmenopausal women.

Increase client movement and exercise.Encourage oral fluids as permitted to maintaina dilute urine.Teach clients to limit intake of food and fluidhigh in calcium.Encourage ingestion of fiber to preventconstipation.Protect a confused client; monitor forpathologic fractures in clients with long-termhypercalcemia.Encourage intake of acid-ash fluids (e.g.,prune or cranberry juice) to counteractdeposits of calcium salts in the urine.

Assess clients receiving digitalis for digitalistoxicity.Hypomagnesemia increases the risk of toxicity.

Take protective measures when there is apossibility of seizures.■ Assess the client’s ability to swallow water

prior to initiating oral feeding.■ Initiate safety measures to prevent injury

during seizure activity.■ Carefully administer magnesium salts as

ordered.Encourage clients to eat magnesium-richfoods if permitted (e.g., whole grains, meat,seafood, and green leafy vegetables).Refer clients to alcohol treatment programs asindicated.

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RISK FACTORS CLINICAL MANIFESTATIONS NURSING INTERVENTIONS

TABLE 52–6 Electrolyte Imbalances—continued

Hypermagnesemia

Abnormal retention of magnesium, as in■ Renal failure■ Adrenal insufficiency

■ Treatment with magnesium salts

Peripheral vasodilation, flushingNausea, vomitingMuscle weakness, paralysisHypotension, bradycardiaDepressed deep-tendon reflexesLethargy, drowsinessRespiratory depression, comaRespiratory and cardiac arrest ifhypermagnesemia is severeLaboratory findings:Serum magnesium above 2.5 mEq/LElectrocardiogram showing prolonged QTinterval, prolonged PR interval, widened QRScomplexes, tall T waves

Monitor vital signs and level of consciousnesswhen clients are at risk.If patellar reflexes are absent, notify theprimary care provider.Advise clients who have renal disease tocontact their primary care provider beforetaking over-the-counter drugs.

CLINICAL ALERTPotassium may be given intravenously for severe hypokalemia. It mustALWAYS be diluted appropriately and NEVER be given IV push. Potassiumthat is to be given IV should be mixed in the pharmacy and double-checked prior to administration by two nurses. The usual concentration ofIV potassium is 20 to 40 mEq/L. ■

CalciumRegulating levels of calcium (Ca2�) in the body is more com-plex than the other major electrolytes so calcium balance can beaffected by many factors. Imbalances of this electrolyte are rel-atively common.

Hypocalcemia is a calcium deficit, or a total serum calciumlevel of less than 8.5 mg/dL or an ionized calcium level of lessthan 4.0 mg/dL. Severe depletion of calcium can cause tetanywith muscle spasms and paresthesias (numbness and tingling

around the mouth and hands and feet) and can lead to convul-sions. Two signs indicate hypocalcemia: The Chvostek’s sign iscontraction of the facial muscles that is produced by tapping thefacial nerve in front of the ear (Figure 52-13 ■, A). Trousseau’ssign is a carpal spasm that occurs by inflating a blood pressurecuff on the upper arm to 20 mm Hg greater than the systolicpressure for 2 to 5 minutes (Figure 52-13 ■, B). Clients at great-est risk for hypocalcemia are those whose parathyroid glandshave been removed. This is frequently associated with total thy-roidectomy or bilateral neck surgery for cancer. Low serummagnesium levels (hypomagnesemia) and chronic alcoholismalso increase the risk of hypocalcemia.

Hypercalcemia, or total serum calcium levels greater than10.5 mg/dL, or an ionized calcium level of greater than 5.0mg/dL, most often occurs when calcium is mobilized from thebony skeleton. This may be due to malignancy or prolonged im-mobilization.

B. Positive Trousseau's SignA. Positive Chvostek's Sign

Figure 52-13 ■ A, Positive Chvostek’s sign. B, Positive Trousseau’s sign.From Lemone, Priscilla; Burke, Karen M., Medical Surgical Nursing: Critical Thinking in Client Care, 3rd ed © 2004. Reproduced with permission of Pearson Education, Inc., UpperSaddle River, New Jersey.

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The risk factors and clinical manifestations related to cal-cium imbalances are found in Table 52–6.

MagnesiumMagnesium (Mg2�) imbalances are relatively common in hospitalized clients, although they may be unrecognized. Hypomagnesemia is a magnesium deficiency, or a total serummagnesium level of less than 1.5 mEq/L. It occurs more fre-quently than hypermagnesemia. Chronic alcoholism is the mostcommon cause of hypomagnesemia. Magnesium deficiency alsomay aggravate the manifestations of alcohol withdrawal, such asdelirium tremens (DTs). Hypermagnesemia is present when theserum magnesium level rises above 2.5 mEq/L. It is due to in-creased intake or decreased excretion. It is often iatrogenic, thatis, a result of overzealous magnesium therapy.

Table 52–6 lists risk factors and manifestations for clientswith altered magesium balance.

ChlorideBecause of the relationship between sodium ions and chlorideions (Cl�), imbalances of chloride commonly occur in conjunc-tion with sodium imbalances. Hypochloremia is a decreasedserum chloride level, in adults a level below 95 mEq/L, and isusually related to excess losses of chloride ion through the GItract, kidneys, or sweating. Hypochloremic clients are at riskfor alkalosis and may experience muscle twitching, tremors, ortetany.

Conditions that cause sodium retention also can lead to a highserum chloride level or hyperchloremia, in adults a level above108 mEq/L. Excess replacement of sodium chloride or potassiumchloride are additional risk factors for high serum chloride levels.The manifestations of hyperchloremia include acidosis, weak-ness, and lethargy, with a risk of dysrhythmias and coma.

PhosphateThe phosphate anion PO4

� is found in both intracellular and ex-tracellular fluid. Most of the phosphorus (P�) in the body existsas PO4

�. Phosphate is critical for cellular metabolism because itis a major component of adenosine triphosphate (ATP).

Phosphate imbalances frequently are related to therapeutic in-terventions for other disorders. Glucose and insulin administra-tion and total parenteral nutrition can cause phosphate to shiftinto the cells from extracellular fluid compartments, leading tohypophosphatemia, defined in adults as a total serum phosphatelevel less than 2.5 mg/dL. Alcohol withdrawal, acid–base imbal-ances, and the use of antacids that bind with phosphate in the GItract are other possible causes of low serum phosphate levels.Manifestations of hypophosphatemia include paresthesias, mus-cle weakness and pain, mental changes, and possible seizures.

Hyperphosphatemia, defined in adults as a total serum phos-phate level greater than 4.5 mg/dL, occurs when phosphate shiftsout of the cells into extracellular fluids (e.g., due to tissue traumaor chemotherapy for malignant tumors), in renal failure, or whenexcess phosphate is administered or ingested. Infants who are fedcow’s milk are at risk for hyperphosphatemia, as are people usingphosphate-containing enemas or laxatives. Clients who have high

serum phosphate levels may experience numbness and tinglingaround the mouth and in the fingertips, muscle spasms, and tetany.

Acid–Base ImbalancesAcid–base imbalances generally are classified as respiratory ormetabolic by the general or underlying cause of the disorder. Car-bonic acid levels are normally regulated by the lungs through theretention or excretion of carbon dioxide, and problems of regula-tion lead to respiratory acidosis or alkalosis. Bicarbonate and hy-drogen ion levels are regulated by the kidneys, and problems ofregulation lead to metabolic acidosis or alkalosis. Healthy regula-tory systems will attempt to correct acid–base imbalances, aprocess called compensation.

Respiratory AcidosisHypoventilation and carbon dioxide retention cause carbonic acidlevels to increase and the pH to fall below 7.35, a conditionknown as respiratory acidosis. Serious lung diseases such asasthma and COPD are common causes of respiratory acidosis.Central nervous system depression due to anesthesia or a narcoticoverdose can sufficiently slow the respiratory rate so that carbondioxide is retained. When respiratory acidosis occurs, the kidneysretain bicarbonate to restore the normal carbonic acid to bicarbon-ate ratio. Recall, however, that the kidneys are relatively slow torespond to changes in acid–base balance, so this compensatoryresponse may require hours to days to restore the normal pH.

Respiratory AlkalosisWhen a person hyperventilates, more carbon dioxide than nor-mal is exhaled, carbonic acid levels fall, and the pH rises togreater than 7.45. This condition is termed respiratory alkalosis.Psychogenic or anxiety-related hyperventilation is a commoncause of respiratory alkalosis. Other causes include fever andrespiratory infections. In respiratory alkalosis, the kidneys willexcrete bicarbonate to return the pH to within the normal range.Often, however, the cause of the hyperventilation is eliminatedand the pH returns to normal before renal compensation occurs.

Metabolic AcidosisWhen bicarbonate levels are low in relation to the amount ofcarbonic acid in the body, the pH falls and metabolic acidosisdevelops. This may develop because of renal failure and the in-ability of the kidneys to excrete hydrogen ion and produce bi-carbonate. It also may occur when too much acid is produced inthe body, for example, in diabetic ketoacidosis or starvationwhen fat tissue is broken down for energy. Metabolic acidosisstimulates the respiratory center, and the rate and depth of res-pirations increase. Carbon dioxide is eliminated and carbonicacid levels fall, minimizing the change in pH. This respiratorycompensation occurs within minutes of the pH imbalance.

Metabolic AlkalosisIn metabolic alkalosis, the amount of bicarbonate in the bodyexceeds the normal 20-to-1 ratio. Ingestion of bicarbonate ofsoda as an antacid is one cause of metabolic alkalosis. Another

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ANATOMY & PHYSIOLOGY REVIEW Gas Exchange

QUESTIONS1. Hypoventilation can affect gas exchange. What are some causes of hypoventilation?2. How does the shallow breathing from hypoventilation cause the PaCO2 to increase and the pH to decrease?3. ABGs that indicate an increased PaCO2 and a decreased pH reflect which acid–base imbalance?4. Hyperventilation can also affect gas exchange. What are some causes of hyperventilation?5. How does hyperventilation cause a decreased PaCO2 and increased pH?6. ABGs that indicate a decreased PaCO2 and an increased pH reflect which acid–base imbalance?

cause is prolonged vomiting with loss of hydrochloric acid fromthe stomach. The respiratory center is depressed in metabolic al-kalosis, and respirations slow and become more shallow. Car-bon dioxide is retained and carbonic acid levels increase,helping balance the excess bicarbonate.

The risk factors and manifestations for acid–base imbalancesare listed in Table 52–7.

NURSING MANAGEMENT

AssessingAssessing clients for fluid, electrolyte, and acid–base balanceand imbalances is an important nursing care function. Compo-nents of the assessment include (a) the nursing history, (b) phys-ical assessment of the client, (c) clinical measurements, and (d) review of laboratory test results.

Nursing HistoryThe nursing history is particularly important for identifyingclients who are at risk for fluid, electrolyte, and acid–base im-balances. The current and past medical history reveal conditionssuch as chronic lung disease or diabetes mellitus that can disruptnormal balances. Medications prescribed to treat acute orchronic conditions (e.g., diuretic therapy for hypertension) alsomay place the client at risk for altered homeostasis. Functional,developmental, and socioeconomic factors must also be consid-ered in assessing the client’s risk. Older people and very youngchildren, clients who must depend on others to meet their needsfor food and fluid intake, and people who cannot afford or donot have the means to cook food for a balanced diet (e.g., home-less people) are at greater risk for fluid and electrolyte imbal-ances. Common risk factors are listed in Box 52–3.

When obtaining the nursing history, the nurse needs to notonly recognize risk factors but also elicit data about the client’s

BronchiolePulmonaryvein

Pulmonaryartery branch

Red blood cellO2 molecule

CO2 moleculeBlood

Capillary wall

Alveolar wall

O2

O2

CO2

CO2

From Turley, Susan M., Medical Language, 1st ed., © 2002.Reproduced with permission of Pearson Education, Inc.,Upper Saddle River, New Jersey.

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TABLE 52–7 Acid–Base ImbalancesRISK FACTORS CLINICAL MANIFESTATIONS NURSING INTERVENTIONS

Respiratory Acidosis

Increased pulse and respiratory ratesHeadache, dizzinessConfusion, decreased level of consciousness(LOC)ConvulsionsWarm, flushed skinChronic:WeaknessHeadacheLaboratory findings:Arterial blood pH less than 7.35PaCO2 above 45 mm HgHCO3

� normal or slightly elevated in acute;above 26 mEq/L in chronic

Complaints of shortness of breath, chesttightnessLight-headedness with circumoral paresthesiasand numbness and tingling of the extremitiesDifficulty concentratingTremulousness, blurred visionLaboratory findings (in uncompensatedrespiratory alkalosis):Arterial blood pH above 7.45PaCO2 less than 35 mm Hg

Kussmaul’s respirations (deep, rapidrespirations)Lethargy, confusionHeadacheWeaknessNausea and vomitingLaboratory findings:Arterial blood pH below 7.35Serum bicarbonate less than 22 mEq/LPaCO2 less than 38 mm Hg with respiratorycompensation

Decreased respiratory rate and depthDizzinessCircumoral paresthesias, numbness andtingling of the extremitiesHypertonic muscles, tetanyLaboratory findings:Arterial blood pH above 7.45Serum bicarbonate greater than 26 mEq/LPaCO2 higher than 45 mm Hg with respiratorycompensation

Acute lung conditions that impairalveolar gas exchange (e.g., pneumonia,acute pulmonary edema, aspiration offoreign body, near-drowning)Chronic lung disease (e.g., asthma,cystic fibrosis, or emphysema)Overdose of narcotics or sedatives thatdepress respiratory rate and depthBrain injury that affects the respiratorycenterAirway obstructionMechanical chest injury

Respiratory Alkalosis

Hyperventilation due to■ Extreme anxiety■ Elevated body temperature■ Overventilation with a mechanical

ventilator■ Hypoxia■ Salicylate overdose

Brain stem injuryFeverIncreased basal metabolic rate

Metabolic Acidosis

Conditions that increase nonvolatileacids in the blood (e.g., renalimpairment, diabetes mellitus,starvation)Conditions that decrease bicarbonate(e.g., prolonged diarrhea)Excessive infusion of chloride-containingIV fluids (e.g., NaCl)Excessive ingestion of acids such assalicylatesCardiac arrest

Metabolic Alkalosis

Excessive acid losses due to■ Vomiting■ Gastric suction

Excessive use of potassium-losingdiureticsExcessive adrenal corticoid hormonesdue to

■ Cushing’s syndrome■ Hyperaldosteronism

Excessive bicarbonate intake from■ Antacids■ Parenteral NaHCO3

Frequently assess respiratory status and lungsounds.Monitor airway and ventilation; insert artificialairway and prepare for mechanical ventilationas necessary.Administer pulmonary therapy measures suchas inhalation therapy, percussion and posturaldrainage, bronchodilators, and antibiotics asordered.Monitor fluid intake and output, vital signs, andarterial blood gases.Administer narcotic antagonists as indicated.Maintain adequate hydration (2–3 L of fluidper day).

Monitor vital signs and ABGs.Assist client to breathe more slowly.Help client breathe in a paper bag or apply arebreather mask (to inhale CO2).

Monitor ABG values, intake and output, andLOC.Administer IV sodium bicarbonate carefully ifordered.Treat underlying problem as ordered.

Monitor intake and output closely.Monitor vital signs, especially respirations, andLOC.Administer ordered IV fluids carefully.Treat underlying problem.

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food and fluid intake, fluid output, and the presence of signs orsymptoms suggestive of altered fluid and electrolyte balance.The Assessment Interview provides examples of questions toelicit information regarding fluid, electrolyte, and acid–basebalance.

Physical AssessmentPhysical assessment to evaluate a client’s fluid, electrolyte,and acid–base status focuses on the skin, the oral cavity andmucous membranes, the eyes, the cardiovascular and respira-tory systems, and neurologic and muscular status. Data fromthis physical assessment are used to expand and verify infor-

mation obtained in the nursing history. The focused physicalassessment is summarized in Table 52–8 on page 1446. Referto Tables 52–5 through 52–8 for possible abnormal findingsrelated to specific imbalances.

Clinical MeasurementsThree simple clinical measurements that the nurse can initiatewithout a primary care provider’s order are daily weights, vitalsigns, and fluid intake and output.

DAILY WEIGHTS. Daily weight measurements provide a rela-tively accurate assessment of a client’s fluid status. Significantchanges in weight over a short time (e.g., more than 5 pounds

BOX 52–3 Common Risk Factors for Fluid, Electrolyte, and Acid–Base Imbalances

CHRONIC DISEASES AND CONDITIONS■ Chronic lung disease (COPD, asthma, cystic fibrosis)■ Heart failure■ Kidney disease■ Diabetes mellitus■ Cushing’s syndrome or Addison’s disease■ Cancer■ Malnutrition, anorexia nervosa, bulimia■ Ileostomy

ACUTE CONDITIONS■ Acute gastroenteritis■ Bowel obstruction■ Head injury or decreased level of consciousness■ Trauma such as burns or crushing injuries■ Surgery■ Fever, draining wounds, fistulas

MEDICATIONS■ Diuretics■ Corticosteroids■ Nonsteroidal anti-inflammatory drugs

TREATMENTS■ Chemotherapy■ IV therapy and total parenteral nutrition■ Nasogastric suction■ Enteral feedings■ Mechanical ventilation

OTHER FACTORS■ Age: Very old or very young■ Inability to access food and fluids independently

ASSESSMENT INTERVIEW Fluid, Electrolyte, and Acid–Base Balance

CURRENT AND PAST MEDICAL HISTORY

■ Are you currently seeing a health care provider for treatment of anychronic diseases such as kidney disease, heart disease, high bloodpressure, diabetes insipidus, or thyroid or parathyroid disorders?

■ Have you recently experienced any acute conditions such as gas-troenteritis, severe trauma, head injury, or surgery? If so, describethem.

MEDICATIONS AND TREATMENTS

■ Are you currently taking any medications on a regular basis suchas diuretics, steroids, potassium supplements, calcium supple-ments, hormones, salt substitutes, or antacids?

■ Have you recently undergone any treatments such as dialysis, par-enteral nutrition, or tube feedings or been on a ventilator? If so,when and why?

FOOD AND FLUID INTAKE

■ How much and what type of fluids do you drink each day?■ Describe your diet for a typical day. (Pay particular attention to the

client’s intake of foods high in sodium content, of protein, and ofwhole grains, fruits, and vegetables.)

■ Have there been any recent changes in your food or fluid intake,for example, as a result of following a weight-loss program?

■ Are you on any type of restricted diet?

■ Has your food or fluid intake recently been affected by changes in ap-petite, nausea, or other factors such as pain or difficulty breathing?

FLUID OUTPUT

■ Have you noticed any recent changes in the frequency or amountof urine output?

■ Have you recently experienced any problems with vomiting, diar-rhea, or constipation? If so, when and for how long?

■ Have you noticed any other unusual fluid losses such as excessivesweating?

FLUID, ELECTROLYTE, AND ACID–BASE IMBALANCES

■ Have you gained or lost weight in recent weeks?■ Have you recently experienced any symptoms such as excessive

thirst, dry skin or mucous membranes, dark or concentrated urine,or low urine output?

■ Do you have problems with swelling of your hands, feet, or ankles?Do you ever have difficulty breathing, especially when lying downor at night? How many pillows do you use to sleep?

■ Have you recently experienced any of the following symptoms: dif-ficulty concentrating or confusion; dizziness or feeling faint; mus-cle weakness, twitching, cramping, or spasm; excessive fatigue;abnormal sensations such as numbness, tingling, burning, or prick-ling; abdominal cramping or distention; heart palpitations?

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in a week or less) are indicative of acute fluid changes. Eachkilogram (2.2 lb) of weight gained or lost is equivalent to 1 Lof fluid gained or lost. Such fluid gains or losses indicatechanges in total body fluid volume rather than in any specificcompartment, such as the intravascular compartment. Rapidlosses or gains of 5% to 8% of total body weight indicate mod-erate to severe fluid volume deficits or excesses.

To obtain accurate weight measurements, the nurse should bal-ance the scale before each use and weigh the client (a) at the sametime each day (e.g., before breakfast and after the first void), (b) wearing the same or similar clothing, and (c) on the same scale.The type of scale (i.e., standing, bed, chair) should be documented.

Regular assessment of weight is particularly important forclients in the community and extended care facilities who are at

risk for fluid imbalance. For these clients, measuring intake andoutput may be impractical because of lifestyle or problems withincontinence. Regular weight measurement, either daily, everyother day, or weekly, provides valuable information about theclient’s fluid volume status.

VITAL SIGNS. Changes in the vital signs may indicate, or insome cases precede, fluid, electrolyte, and acid–base imbal-ances. For example, elevated body temperature may be a re-sult of dehydration or a cause of increased body fluid losses.

Tachycardia is an early sign of hypovolemia. Pulse volumewill decrease in FVD and increase in FVE. Irregular pulserates may occur with electrolyte imbalances. Changes in re-spiratory rate and depth may cause respiratory acid–base im-

TABLE 52–8 Focused Physical Assessment for Fluid, Electrolyte, or Acid–Base ImbalancesSYSTEM ASSESSMENT FOCUS TECHNIQUE POSSIBLE ABNORMAL FINDINGSSkin

Mucous membranes

EyesFontanels (infant)

Cardiovascular system

Respiratory system

Neurologic

Color, temperature, moisture

Turgor

Edema

Color, moisture

FirmnessFirmness, level

Heart rate

Peripheral pulsesBlood pressure

Capillary refillVenous filling

Respiratory rate and pattern

Lung soundsLevel of consciousness (LOC)

Orientation, cognition

Motor functionReflexesAbnormal reflexes

Inspection, palpation

Gently pinch up a fold of skin oversternum or inner aspect of thigh foradults, on the abdomen or medialthigh for childrenInspect for visible swelling aroundeyes, in fingers, and in lowerextremitiesCompress the skin over the dorsumof the foot, around the ankles, overthe tibia, in the sacral areaInspection

Gently palpate eyeball with lid closedInspect and gently palpate anteriorfontanelAuscultation, cardiac monitor

PalpationAuscultation of Korotkoff’s soundsBP assessment lying and standingPalpationInspection of jugular veins and handveinsInspection

AuscultationObservation, stimulation

Questioning

Strength testingDeep-tendon reflex (DTR) testingChvostek’s sign: Tap over facial nerveabout 2 cm anterior to tragus of earTrousseau’s sign: Inflate a bloodpressure cuff on the upper arm to 20 mm Hg greater than the systolicpressure, leave in place for 2 to 5 minutes

Flushed, warm, very dryMoist or diaphoreticCool and palePoor turgor: Skin remains tented forseveral seconds instead ofimmediately returning to normalpositionSkin around eyes is puffy, lids appearswollen; rings are tight; shoes leaveimpressions on feetDepression remains (pitting): seescale for describing edema in Figure 52-11Mucous membranes dry, dull inappearance; tongue dry and crackedEyeball feels soft to palpationFontanel bulging, firmFontanel sunken, softTachycardia, bradycardia; irregular;dysrhythmiasWeak and thready; boundingHypotensionPostural hypotensionSlowed capillary refillJugular venous distention; flat jugularveins, poor venous refillIncreased or decreased rate anddepth of respirationsCrackles or moist ralesDecreased LOC, lethargy, stupor, orcomaDisoriented, confused; difficultyconcentratingWeakness, decreased motor strengthHyperactive or depressed DTRsFacial muscle twitching includingeyelids and lips on side of stimulusCarpal spasm: contraction of handand fingers on affected side

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balances or act as a compensatory mechanism in metabolicacidosis or alkalosis.

Blood pressure, a sensitive measure to detect blood volumechanges, may fall significantly with FVD and hypovolemia orincrease with FVE. Postural, or orthostatic, hypotension mayalso occur with FVD and hypovolemia.

To assess for orthostatic hypotension, measure the client’sblood pressure and pulse in a supine position. Allow the clientto remain in that position for 3 to 5 minutes, leaving the bloodpressure cuff on the arm. Stand the client up and immediatelyreassess the blood pressure and pulse. A drop of 10 to 15 mm Hgin the systolic blood pressure with a corresponding drop in di-astolic pressure and an increased pulse rate (by 10 or more beatsper minute) is indicative of orthostatic or postural hypotension.

FLUID INTAKE AND OUTPUT. The measurement and record-ing of all fluid intake and output (I & O) during a 24-hour pe-riod provides important data about the client’s fluid andelectrolyte balance. Generally, intake and output are measuredfor hospitalized at-risk clients.

The unit used to measure intake and output is the milliliter(mL) or cubic centimeter (cc); these are equivalent metric unitsof measurement. In household measures, 30 mL is roughlyequivalent to 1 fluid ounce, 500 mL is about 1 pint, and 1,000 mLis about 1 quart. To measure fluid intake, nurses convert house-hold measures such as a glass, cup, or soup bowl to metric units.Most agencies provide conversion tables, since the sizes ofdishes vary from agency to agency. Such a table is often providedon or with the bedside I & O record. Examples of equivalents aregiven in Box 52–4.

Most agencies have a form for recording I & O, usually abedside record on which the nurse lists all items measured andthe quantities per shift (Figure 52-14 ■). Some agencies haveanother form for recording the specifics of intravenous fluids,such as the type of solution, additives, time started, amounts ab-sorbed, and amounts remaining per shift.

It is important to inform clients, family members, and allcaregivers that accurate measurements of the client’s fluid in-

take and output are required, explaining why and emphasizingthe need to use a bedpan, urinal, commode, or in-toilet collec-tion device (unless a urinary drainage system is in place). In-struct the client not to put toilet tissue into the container withurine. Clients who wish to be involved in recording fluid intakemeasurements need to be taught how to compute the values andwhat foods are considered fluids.

To measure fluid intake, the nurse records on the I & O formeach fluid item taken (if the client has not already done so),specifying the time and type of fluid. All of the following fluidsneed to be recorded:

■ Oral fluids. Water, milk, juice, soft drinks, coffee, tea,cream, soup, and any other beverages. Include water takenwith medications. To assess the amount of water takenfrom a water pitcher, measure what remains and subtractthis amount from the volume of the full pitcher. Then refillthe pitcher.

■ Ice chips. Record the fluid as approximately one-half the vol-ume of the ice chips. For example, if the ice chips fill a cupholding 200 mL and the client consumed all of the ice chips,the volume consumed would be recorded as 100 mL.

■ Foods that are or tend to become liquid at room temperature.These include ice cream, sherbert, custard, and gelatin. Donot measure foods that are pureed, because purees are sim-ply solid foods prepared in a different form.

■ Tube feedings. Remember to include the 30- to 60-mL waterflush at the end of intermittent feedings or during continuousfeedings.

■ Parenteral fluids. The exact amount of intravenous fluid ad-ministered is to be recorded, since some fluid containers maybe overfilled. Blood transfusions are included.

■ Intravenous medications. Intravenous medications that areprepared with solutions such as normal saline (NS) and are

BOX 52—4 Commonly Used Fluid Containersand Their Volumes

Water glass 200 mLJuice glass 120 mLCup 180 mLSoup bowl

Adult 180 mLChild 100 mL

Teapot 240 mLCreamer

Large 90 mLSmall 30 mL

Water pitcher 1,000 mLJello, custard dish 100 mLIce cream dish 120 mLPaper cup

Large 200 mLSmall 120 mL

Figure 52-14 ■ A sample 24-hour fluid intake and output record.

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administered as an intermittent or continuous infusion mustalso be included (e.g., ceftazidime 1 g in 50 mL of sterile wa-ter). Most intravenous medications are mixed in 50 to 100 mLof solution.

■ Catheter or tube irrigants. Fluid used to irrigate urinarycatheters, nasogastric tubes, and intestinal tubes must bemeasured and recorded if not immediately withdrawn.

To measure fluid output, measure the following fluids (re-member to observe appropriate infection control precautions):

■ Urinary output. Following each voiding, pour the urine intoa measuring container, observe the amount, and record it andthe time of voiding on the I & O form. For clients with reten-tion catheters, empty the drainage bag into a measuring con-tainer at the end of the shift (or at prescribed times if outputis to be measured more often). Note and record the amountof urine output. In intensive care areas, urine output often ismeasured hourly. If the client is incontinent of urine, esti-mate and record these outputs. For example, for an inconti-nent client the nurse might record “Incontinent × 3” or“Drawsheet soaked in 12-in. diameter.” A more accurate es-timate of the urine output of infants and incontinent clientsmay be obtained by first weighing diapers or incontinentpads that are dry, and then subtracting this weight from theweight of the soiled items. Each gram of weight left aftersubtracting is equal to 1 mL of urine. If urine is frequentlysoiled with feces, the number of voidings may be recordedrather than the volume of urine.

■ Vomitus and liquid feces. The amount and type of fluid andthe time need to be specified.

■ Tube drainage, such as gastric or intestinal drainage.■ Wound drainage and draining fistulas. Wound drainage may

be recorded by documenting the type and number of dress-ings or linen saturated with drainage or by measuring the ex-act amount of drainage collected in a vacuum drainage (e.g.,Hemovac) or gravity drainage system.

Fluid intake and output measurements are totaled at the endof the shift (every 8 to 12 hours), and the totals are recorded inthe client’s permanent record. In intensive care areas, the nursemay record intake and output hourly. Usually the staff on nightshift totals the amounts of I & O recorded for each shift andrecords the 24-hour total.

To determine whether the fluid output is proportional to fluidintake or whether there are any changes in the client’s fluid status,the nurse (a) compares the total 24-hour fluid output measurementwith the total fluid intake measurement and (b) compares both toprevious measurements. Urinary output is normally equivalent tothe amount of fluids ingested; the usual range is 1,500 to 2,000 mLin 24 hours, or 40 to 80 mL in 1 hour (0.5 mL/kg/hour). Clientswhose output substantially exceeds intake are at risk for fluid vol-ume deficit. By contrast, clients whose intake substantially ex-ceeds output are at risk for fluid volume excess. In assessing theclient’s fluid balance it is important to consider additional factorsthat may affect intake and output. The client who is extremely di-aphoretic or who has rapid, deep respirations has fluid losses that

cannot be measured but must be considered in evaluating fluidstatus.

When there is a significant discrepancy between intake andoutput or when fluid intake or output is inadequate (for exam-ple, a urine output of less than 500 mL in 24 hours or less than0.5 mL per kilogram per hour in an adult), this informationshould be reported to the charge nurse or primary care provider.

Laboratory TestsMany laboratory studies are conducted to determine the client’sfluid, electrolyte, and acid–base status. Some of the more com-mon tests are discussed here.

SERUM ELECTROLYTES. Serum electrolyte levels are oftenroutinely ordered for any client admitted to the hospital as ascreening test for electrolyte and acid–base imbalances.Serum electrolytes also are routinely assessed for clients atrisk in the community, for example, clients who are beingtreated with a diuretic for hypertension or heart failure. Themost commonly ordered serum tests are for sodium, potas-sium, chloride, magnesium, and bicarbonate ions. Normal val-ues of commonly measured electrolytes are shown in Box52–5. Some primary care providers use a diagram format forkeeping track of the client’s electrolytes when documenting intheir progress notes. See Figure 52-15 ■.

BOX 52—5 Normal Electrolyte Values for Adults*

VENOUS BLOODSodium 135–145 mEq/LPotassium 3.5–5.0 mEq/LChloride 95–108 mEq/LCalcium (total) 4.5–5.5 mEq/L or 8.5–10.5 mg/dL(ionized) 56% of total calcium (2.5 mEq/L or

4.0–5.0 mg/dL)Magnesium 1.5–2.5 mEq/L or 1.6–2.5 mg/dLPhosphate (phosphorus) 1.8–2.6 mEq/L or 2.5 – 4.5 mg/dLSerum osmolality 280–300 mOsm/kg water

*Normal laboratory values vary from agency to agency.

Na

K

ClBUN

CRCO2

A.

142

4.2

10210

0.828

B.

Figure 52-15 ■ A, Format for a diagram of serum electrolyte results.B, Example that may be seen in a primary care provider’sdocumentation notes.

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COMPLETE BLOOD COUNT (CBC). The complete bloodcount, another basic screening test, includes information aboutthe hematocrit (Hct). The hematocrit measures the volume(percentage) of whole blood that is composed of RBCs. Be-cause the hematocrit is a measure of the volume of cells in re-lation to plasma, it is affected by changes in plasma volume.Thus the hematocrit increases with severe dehydration and de-creases with severe overhydration. Normal hematocrit valuesare 40% to 54% (men) and 37% to 47% (women).

OSMOLALITY. Serum osmolality is a measure of the soluteconcentration of the blood. The particles included are sodiumions, glucose, and urea (blood urea nitrogen, or BUN). Serumosmolality can be estimated by doubling the serum sodium,because sodium and its associated chloride ions are the majordeterminants of serum osmolality. Serum osmolality valuesare used primarily to evaluate fluid balance. Normal values are280 to 300 mOsm/kg. An increase in serum osmolality indi-cates a fluid volume deficit; a decrease reflects a fluid volumeexcess.

Urine osmolality is a measure of the solute concentrationof urine. The particles included are nitrogenous wastes, suchas creatinine, urea, and uric acid. Normal values are 500 to800 mOsm/kg. An increased urine osmolality indicates afluid volume deficit; a decreased urine osmolality reflects afluid volume excess.

URINE pH. Measurement of urine pH may be obtained by lab-oratory analysis or by using a dipstick on a freshly voidedspecimen. Because the kidneys play a critical role in regulat-ing acid–base balance, assessment of urine pH can be useful indetermining whether the kidneys are responding appropriatelyto acid–base imbalances. Normally the pH of the urine is rel-atively acidic, averaging about 6.0, but a range of 4.6 to 8.0 isconsidered normal. In metabolic acidosis, urine pH should de-crease as the kidneys excrete hydrogen ions; in metabolic al-kalosis, the pH should increase.

URINE SPECIFIC GRAVITY. Specific gravity is an indicator ofurine concentration that can be performed quickly and easily bynursing personnel. Normal specific gravity ranges from 1.005 to1.030 (usually 1.010 to 1.025). When the concentration ofsolutes in the urine is high, the specific gravity rises; in very di-lute urine with few solutes, it is abnormally low.

URINE SODIUM AND CHLORIDE EXCRETION. These are indi-cators of renal perfusion and can provide useful informationabout a client’s fluid status. With hypovolemia, aldosteronewill be secreted. This will cause reabsorption of sodium andchloride which will result in decreased levels of sodium andchloride, less than 20 mEq/L each (Elgart, 2004).

ARTERIAL BLOOD GASES. Arterial blood gases (ABGs) are per-formed to evaluate the client’s acid–base balance and oxy-genation. Arterial blood is used because it provides a truerreflection of gas exchange in the pulmonary system than ve-nous blood. Blood gases may be drawn by laboratory techni-cians, respiratory therapy personnel, or nurses with

specialized skills. Because a high-pressure artery is used toobtain blood, it is important to apply pressure to the puncturesite for 5 minutes after the procedure to reduce the risk ofbleeding or bruising.

Six measurements are commonly used to interpret arterialblood gas tests (Simpson, 2004):

■ pH: a measure of the relative acidity or alkalinity of theblood. The greater the number of hydrogen ions, the moreacidic the solution is. The normal range for pH is narrow, anddeath may ensue with pH values below 6.8 or above 7.8.

■ PaO2: the pressure exerted by oxygen dissolved in theplasma of arterial blood; an indirect measure of blood oxy-gen content. This measure, representing one of the two formsin which oxygen is transported in the blood, accounts foronly about 3% of oxygen content in the blood.

■ PaCO2: the partial pressure of carbon dioxide in arterialplasma; the respiratory component of acid–base determination.Carbon dioxide is regulated by the lungs, and the PaCO2 is usedto determine if an acid–base imbalance is respiratory in origin.

■ Bicarbonate HCO3�: a measure of the metabolic component

of acid–base balance.■ Base excess (BE): a calculated value of bicarbonate levels,

also reflective of the metabolic component of acid–base bal-ance. If the number is preceded by a plus sign, it is a base ex-cess and indicates alkalosis; if preceded by a minus sign, it isa base deficit and indicates acidosis.

■ Oxygen saturation (SpO2): the percentage of hemoglobinsaturated (combined) with oxygen. This represents the otherform in which oxygen is transported in the blood and ac-counts for about 97% of the oxygen in the blood.

Normal ABG values are listed in Box 52–6. Changes seen incommon acid–base imbalances are summarized in Table 52–9.Note that although the PaO2 and SpO2 are important for assess-ing respiratory status, they generally do not provide useful in-formation for assessing acid–base balance and so are notincluded in this table.

When evaluating ABG results to determine acid–base bal-ance, it is important to use a systematic approach such as the oneoutlined in Box 52–7. Nurses need to assess each measurementindividually, then look at the interrelationships to determinewhat type of acid–base imbalance may be present.

BOX 52—6 Normal Values of Arterial Blood Gases*

pH 7.35–7.45PaO2 80–100 mm HgPaCO2 35–45 mm HgHCO3

� 22–26 mEq/LBase excess �2 to �2 mEq/LO2 saturation 95–98%

*Some normal values will vary according to the kind of test carried out in the labo-ratory. Nurses are advised to use the normal values issued by the agency when in-terpreting laboratory results.

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DiagnosingNANDA includes the following diagnostic labels that relate tofluid and acid–base imbalances:

■ Deficient Fluid Volume: Decreased intravascular, interstitial,and/or intracellular fluid. This refers to dehydration, waterloss alone without change in sodium.

■ Excess Fluid Volume: Increased isotonic fluid retention.

■ Risk for Imbalanced Fluid Volume: At risk for a decrease, in-crease, or rapid shift from one to the other of intravascular,interstitial, and/or intracellular fluid. This refers to body fluidloss, gain, or both.

■ Risk for Deficient Fluid Volume: At risk for experiencingvascular, cellular, or intracellular dehydration.

■ Impaired Gas Exchange: Excess or deficit in oxygenation and/orcarbon dioxide elimination at the alveolar-capillary membrane.

BOX 52—7 Interpreting ABGs — Do You Have a Match?

1. Look at each number separately.■ Label the pH:

● If the pH is less than 7.35, the problem is acidosis.● If the pH is greater than 7.45, the problem is alkalosis.

■ Label the PaCO2:● If the PaCO2 is less than 35 mm Hg, more carbon dioxide is

being exhaled than normal and indicates alkalosis.● If the PaCO2 is greater than 45 mm Hg, less carbon dioxide

is being exhaled than normal and indicates acidosis.■ Label the bicarbonate:

● If the HCO3� is less than 22 mEq/L, bicarbonate levels are

lower than normal, indicating acidosis.● If the HCO3

� is greater than 26 mEq/L, bicarbonate levels arehigher than normal, indicating alkalosis.

2. Determine the cause of the acid–base imbalance.■ Look at the pH—is it acidosis or alkalosis?

3. Determine if the origin of the imbalance is respiratory or metabolic.■ Check the PaCO2 and HCO3

� which one MATCHES the sameacid–base status as the pH?EXAMPLEpH � 7.33 (acidosis)PaCO2 � 55 (acidosis)HCO3 � 29 (alkalosis)Cause of imbalance (hint: look at pH) � acidosis.PaCO2 (acidosis) MATCHES the pH (acidosis) � respiratoryproblemClient has respiratory acidosis.

4. Look for evidence of compensation.■ Look at the value that does NOT match the pH:

● If it (e.g., PaCO2 or HCO3 ) is within normal range, there is nocompensation.

● If it (e.g., PaCO2 or HCO3 ) is above or below normal range,the body is compensating.

EXAMPLESa. In respiratory acidosis (pH < 7.35, PaCO2 > 45 mm Hg), if

the HCO3� is greater than 26 mEq/L, the kidneys are retain-

ing bicarbonate to minimize the acidosis: renal compensation.b. In respiratory alkalosis (pH > 7.45, PaCO2 < 35 mm Hg),

if the HCO3� is less than 22 mEq/L, the kidneys are ex-

creting bicarbonate to minimize the alkalosis: again, renalcompensation.

c. In metabolic acidosis (pH < 7.35, HCO3� < 22 mEq/L),

if the PaCO2 is less than 35 mm Hg, carbon dioxide isbeing “blown off” to minimize the acidosis: respiratorycompensation.

d. In metabolic alkalosis (pH > 7.45, HCO3� > 26 mEq/L), if

the PaCO2 is greater than 45 mm Hg, carbon dioxide isbeing retained to compensate for excess base: again, re-spiratory compensation.

Note: If the value that doesn’t match (e.g., PaCO2 or HCO3 ) is above or below normaland the pH is within normal range, the body has completely compensated. Completecompensation takes time to develop and is the result of a chronic condition (e.g.,chronic respiratory acidosis with COPD).

TABLE 52–9 Arterial Blood Gas Values in Common Acid–Base DisordersDISORDER ABG VALUESRespiratory acidosis

Respiratory alkalosis

Metabolic acidosis

Metabolic alkalosis

pHPaCO2

HCO3�

pHPaCO2

HCO3�

pHPaCO2

HCO3�

pHPaCO2

HCO3�

< 7.35> 45 mm Hg (excess CO2 and carbonic acid)Normal; or >26 mEq/L with renal compensation

> 7.45< 35 mm Hg (inadequate CO2 and carbonic acid)Normal; or < 22 mEq/L with renal compensation

< 7.35Normal; or < 35 mm Hg with respiratory compensation< 22 mEq/L (inadequate bicarbonate)

> 7.45Normal; or > 45 mm Hg with respiratory compensation> 26 mEq/L (excess bicarbonate)

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■ Prevent associated risks (tissue breakdown, decreased car-diac output, confusion, other neurologic signs).

Obviously, goals will vary according to the diagnosis anddefining characteristics for each individual. Appropriate pre-ventive and corrective nursing interventions that relate to thesemust be identified. Specific nursing activities can be selected tomeet the client’s individual needs. Examples of application ofthese using NANDA, NIC, and NOC designations are shown inIdentifying Nursing Diagnoses, Outcomes, and Interventionsand in the Nursing Care Plan and the Concept Map at the end ofthis chapter. Examples of NIC interventions related to fluid,electrolyte, and acid–base balance include the following:

■ Acid–base management■ Electrolyte management■ Fluid monitoring■ Hypovolemia management■ Intravenous (IV) therapy

Specific nursing activities associated with each of these in-terventions can be selected to meet the individual needs of theclient.

Nursing activities to meet goals and outcomes related tofluid, electrolyte, and acid–base imbalances are discussed inthe next section. These include (a) monitoring fluid intake andoutput, cardiovascular and respiratory status, and results of lab-oratory tests; (b) assessing the client’s weight; location and ex-tent of edema, if present; skin turgor and skin status; specificgravity of urine; and level of consciousness and mental status;

Clinical applications of selected diagnoses are shown inIdentifying Nursing Diagnoses, Outcomes, and Interventionsand in the Nursing Care Plan and the Concept Map at the end ofthis chapter.

Fluid, electrolyte, and acid–base imbalances affect manyother body areas and as a consequence may be the etiology ofother nursing diagnoses, such as

■ Impaired Oral Mucous Membrane related to fluid volumedeficit.

■ Impaired Skin Integrity related to dehydration and/or edema.■ Decreased Cardiac Output related to hypovolemia and/or

cardiac dysrhythmias secondary to electrolyte imbalance(K� or Mg2�).

■ Ineffective Tissue Perfusion related to decreased cardiac out-put secondary to fluid volume deficit or edema.

■ Activity Intolerance related to hypervolemia.■ Risk for Injury related to calcium shift out of bones into ex-

tracellular fluids.■ Acute Confusion related to electrolyte imbalance.

PlanningWhen planning care the nurse identifies nursing interventionsthat will assist the client to achieve these broad goals:

■ Maintain or restore normal fluid balance.■ Maintain or restore normal balance of electrolytes in the in-

tracellular and extracellular compartments.■ Maintain or restore pulmonary ventilation and oxygenation.

NURSING DIAGNOSIS/DEFINITION

SAMPLE DESIREDOUTCOMES*/DEFINITION INDICATORS

SELECTEDINTERVENTIONS*/

DEFINITION SAMPLE NIC ACTIVITIES

Fluid Management[4120]/Promotion offluid balance and pre-vention of complica-tions resulting fromabnormal or unde-sired fluid levels

Not compromised:■ 24-hour

intake andoutput

■ Stable bodyweight

No:■ Adventitious

breathsounds

■ Neck veindistention

Fluid Balance[0601]/Water balancein the intracellular andextracellular compart-ments of the body

* The NOC # for desired outcomes and the NIC # for nursing interventions are listed in brackets following the appropriate outcome or intervention. Outcomes, indicators, inter-

ventions, and activites selected are only a sample of those suggested by NOC and NIC and should be further individualized for each client.

Excess Fluid Volume/Increased isotonic fluid retention

■ Assess location and extent of edemaon scale from 1� to 4�

■ Monitor for indications of fluid over-load/retention (e.g., crackles, ele-vated BP, edema, neck veindistention) as appropriate

■ Maintain accurate intake and outputrecord

■ Weigh daily and monitor trends■ Consult primary care provider if signs

and symptoms of fluid volume ex-cess persist or worsen

IDENTIFYING NURSING DIAGNOSES, OUTCOMES, AND INTERVENTIONSClients with Fluid Volume Excess

DATA CLUSTER Tom Bricker, a 67-year-old pensioner who has a history of heart disease, has experienced a weight gain of 4 to 5 kg (9 to 11lb) during the past month. He states his rings are too tight to remove, his ankles are swollen, his heart pounds at times, he gets breathless withexertion, and he feels bloated. Physical findings reveal jugular vein distention above 3 cm; delayed emptying of hand veins; bounding pulse (86);pitting edema in feet, ankles, and lower legs; and moist lung sounds (rales/crackles).

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(c) fluid intake modifications; (d) dietary changes; (e) par-enteral fluid, electrolyte, and blood replacement; and (f) other appropriate measures such as administering pre-scribed medications and oxygen, providing skin care and oralhygiene, positioning the client appropriately, and schedulingrest periods.

Planning for Home CareTo provide for continuity of care, the client’s needs for assis-tance with care in the home need to be considered. Homecare planning includes assessment of the client’s and fam-ily’s resources and abilities for care, and the need for refer-

NURSING DIAGNOSIS/DEFINITION

SAMPLE DESIREDOUTCOMES*/DEFINITION INDICATORS

SELECTEDINTERVENTIONS*/

DEFINITION SAMPLE NIC ACTIVITIES

Acid–Base Manage-ment: Respiratory Acidosis [1913]/Promotion ofacid–base balanceand prevention ofcomplications result-ing from serum PCO2

levels higher than desired

Not compromised■ Depth of

inspiration■ Auscultated

breathsounds

Respiratory Status: Ventilation [0403]/Movement of air inand out of the lungs

*The NOC # for desired outcomes and the NIC # for nursing interventions are listed in brackets following the appropriate outcome or intervention. Outcomes, indicators, inter-

ventions, and activites selected are only a sample of those suggested by NOC and NIC and should be further individualized for each client.

Impaired GasExchange/Excess or deficitin oxygenation and/orcarbon dioxide eliminationat the alveolar-capillarymembrane

■ Monitor respiratory pattern■ Monitor ABG levels for decreasing pH

level, as appropriate■ Monitor neurological status (e.g., level

of consciousness and confusion)■ Monitor determinants of tissue oxy-

gen delivery (e.g., PaO2, SaO2, hemo-globin levels)

■ Provide mechanical ventilatory sup-port if necessary

IDENTIFYING NURSING DIAGNOSES, OUTCOMES, AND INTERVENTIONSClients with Impaired Gas Exchange

DATA CLUSTER Fred Boysniak was admitted to emergency after being found with an empty bottle of morphine tablets by his bed. He appearsvery lethargic and stuporous; pulse is 120, respiration 12 and very shallow. Blood gases reveal pH of 7.28, PaCO2 49 mm Hg, and HCO3

� 25mEq/L.

rals and home health services. The accompanying HomeCare Assessment describes the specific assessment data re-quired to establish a home care plan. Based on the data gath-ered in assessment of the home situation, the nurse tailors theteaching plan for the client and family (see Client Teachingon page 1453).

ImplementingPromoting WellnessMost people rarely think about their fluid, electrolyte, oracid–base balance. They know it is important to drink adequate

HOME CARE ASSESSMENT Fluid, Electrolyte, and Acid–Base Balance

CLIENT

■ Risk factors for imbalances: The client’s age, medications requiredsuch as diuretic therapy or corticosteroids, and presence of chronicdiseases such as diabetes mellitus, heart disease, lung disease, ordementia (see Box 52–3 on p. 1445)

■ Self-care abilities for maintaining food and fluid intake: Mobility;ability to chew and swallow, to access fluids and respond to thirst,to purchase food and prepare a balanced diet

■ Current level of knowledge (as appropriate) about: Prescribed diet,any fluid restrictions, activity restrictions, actions and side effects ofprescribed medications, regular weight monitoring, gastric tubecare and enteral feedings, central line or PICC catheter care, andparenteral fluids and nutrition

FAMILY

■ Caregiver availability, skills, and responses: Availability and willing-ness to assume responsibility for care, knowledge and ability to

provide assistance with preparing food and maintaining adequateintake of food and fluids, knowledge of risk factors and early warn-ing signs of problems

■ Family role changes and coping: Effect on financial status, parent-ing and spousal roles, social roles

■ Alternate potential primary or respite caregivers: For example,other family members, volunteers, church members, paid care-givers or housekeeping services; available community respite care(e.g., adult day care, senior centers)

COMMUNITY

■ Current knowledge of and experience with community resources:Home health agencies, organizations that offer financial assistanceor assistance with food preparation, Meals on Wheels or meal ser-vices (e.g., at senior centers, homeless shelters), pharmacies,home intravenous services, respiratory care services

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fluids and consume a balanced diet, but they may not under-stand the potential effects when this is not done. Nurses can pro-mote clients’ health by providing wellness teaching that willhelp them maintain fluid and electrolyte balance.

Enteral Fluid and Electrolyte ReplacementFluids and electrolytes can be provided orally in the home andhospital if the client’s health permits, that is, if the client is notvomiting, has not experienced an excessive fluid loss, and has

CLIENT TEACHING Promoting Fluid and Electrolyte Balance

■ Consume six to eight glasses of water daily.■ Avoid excess amounts of foods or fluids high in salt, sugar, and

caffeine.■ Eat a well-balanced diet. Include adequate amounts of milk or milk

products to maintain bone calcium levels.■ Limit alcohol intake because it has a diuretic effect.■ Increase fluid intake before, during, and after strenuous exercise,

particularly when the environmental temperature is high, and re-place lost electrolytes from excessive perspiration as needed withcommercial electrolyte solutions.

■ Maintain normal body weight.■ Learn about and monitor side effects of medications that affect

fluid and electrolyte balance (e.g., diuretics) and ways to handleside effects.

■ Recognize possible risk factors for fluid and electrolyte imbalancesuch as prolonged or repeated vomiting, frequent watery stools, orinability to consume fluids because of illness.

■ Seek prompt professional health care for notable signs of fluid im-balance such as sudden weight gain or loss, decreased urine vol-ume, swollen ankles, shortness of breath, dizziness, or confusion.

CLIENT TEACHING Home Care and Fluid, Electrolyte, and Acid–Base Balance

MONITORING FLUID INTAKE AND OUTPUT

■ Teach and provide the rationale for monitoring fluid intake andoutput to the client and family as appropriate. Include how touse a commode or collection device (“hat”) in the toilet, how toempty and measure urinary catheter drainage, and how to countor weigh diapers.

■ Instruct and provide the rationale for regular weight monitoringto the client and family. Weigh at the same time of day, using thesame scale and with the client wearing the same amount ofclothing.

■ Educate and provide the rationale to the client and family on whento contact a health care professional, such as in the cases of a sig-nificant change in urine output; any change of 5 pounds or morein a 1- to 2-week period; prolonged episodes of vomiting, diarrhea,or inability to eat or drink; dry, sticky mucous membranes; extremethirst; swollen fingers, feet, ankles, or legs; difficulty breathing,shortness of breath, or rapid heartbeat; and changes in behavioror mental status.

MAINTAINING FOOD AND FLUID INTAKE

■ Instruct the client and family about any diet or fluid restrictions,such as a low-sodium diet.

■ Teach family members the rationale for the importance of offeringfluids regularly to clients who are unable to meet their own needsbecause of age, impaired mobility or cognition, or other conditionssuch as impaired swallowing due to a stroke.

■ If the client is on enteral or intravenous fluids and feeding at home,teach and provide the underlying rationale to caregivers aboutproper administration and care. Contact a home health or homeintravenous service to provide services and teaching.

SAFETY

■ Instruct and provide the rationale to the client to change positionsslowly if appropriate, especially when moving from a supine to asitting or standing position.

■ Inform and provide the rationale to the client and family about theimportance of good mouth and skin care. Teach the client tochange positions frequently and to elevate the feet on a stoolwhen sitting for a long period.

■ Teach the client and family how to care for intravenous access sitesor gastric tubes. Include what to do if tubes become dislodged.

MEDICATIONS

■ Emphasize the importance of and rationale for taking medicationsas prescribed.

■ Instruct clients taking diuretics to take the medication in the morn-ing. If a second daily dose is prescribed, they should take it in thelate afternoon to avoid disrupting sleep to urinate.

■ Inform clients about any expected side effects of prescribed med-ications and how to handle them (e.g., if a potassium-depleting di-uretic is prescribed, increase intake of potassium-rich foods; iftaking a potassium-sparing diuretic, avoid excess potassium intakesuch as using a salt substitute).

■ Teach clients when to contact their primary care provider, for ex-ample, if they are unable to take a prescribed medication or havesigns of an allergic or toxic reaction to a medication.

MEASURES SPECIFIC TO CLIENT’S PROBLEM

■ Provide instructions and rationale specific to the client’s fluid, elec-trolyte, or acid–base imbalance, such asa. Fluid volume deficit.b. Risk for fluid volume deficit.c. Fluid volume excess.

REFERRALS

■ Make appropriate referrals to home health or community social ser-vices for assistance with resources such as meals, meal preparationand food, intravenous infusions and access, enteral feedings, andhomemaker or home health aide services to help with ADLs.

COMMUNITY AGENCIES AND OTHER SOURCES OF HELP

■ Provide information about companies or agencies that can providedurable medical equipment such as commodes, lift chairs, or hos-pital beds for purchase, for rental, or free of charge.

■ Provide a list of sources for supplies such as catheters anddrainage bags, measuring devices, tube feeding formulas, andelectrolyte replacement drinks.

■ Suggest additional sources of information and help such as theAmerican Dietetic Association, the American Heart Association,and the American Lung Association.

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an intact gastrointestinal tract and gag and swallow reflexes.Clients who are unable to ingest solid foods may be able to in-gest fluids.

FLUID INTAKE MODIFICATIONS. Increased fluids (ordered as“push fluids”) are often prescribed for clients with actual orpotential fluid volume deficits arising, for example, from milddiarrhea or mild to moderate fevers. Guidelines for helpingclients increase fluid intake are shown in the above PracticeGuidelines.

Restricted fluids may be necessary for clients who have fluidretention (fluid volume excess) as a result of renal failure, con-gestive heart failure, SIADH, or other disease processes. Fluidrestrictions vary from “nothing by mouth” to a precise amountordered by a primary care provider. The restriction of fluids canbe difficult for some clients, particularly if they are experienc-ing thirst. Guidelines for helping clients restrict fluid intake areshown in Practice Guidelines.

DIETARY CHANGES. Specific fluid and electrolyte imbal-ances may require simple dietary changes. For example,clients receiving potassium-depleting diuretics need to be in-formed about foods with a high potassium content (e.g., ba-nanas, oranges, and leafy greens). Some clients with fluidretention need to avoid foods high in sodium. Most healthyclients can benefit from foods rich in calcium.

ORAL ELECTROLYTE SUPPLEMENTS. Some clients can bene-fit from oral supplements of electrolytes, particularly when amedication is prescribed that affects electrolyte balance, whendietary intake is inadequate for a specific electrolyte, or whenfluid and electrolyte losses are excessive as a result of, for ex-ample, excessive perspiration.

Corticosteroids and many diuretics can cause too muchpotassium to be eliminated through the kidneys. For clients tak-ing these medications, potassium supplements may be pre-scribed. Instruct clients taking oral potassium supplements to

PRACTICE GUIDELINES Facilitating Fluid Intake

■ Explain to the client the reason for the required intake and thespecific amount needed. This provides a rationale for the re-quirement and promotes compliance.

■ Establish a 24-hour plan for ingesting the fluids. For the hospi-talized or long-term care client, half of the total volume is givenduring the day shift, and the other half is divided between theevening and night shifts, with most of that ingested during theevening shift. For example, if 2,500 mL is to be ingested in 24hours, the plan may specify 7–3 (1,500 mL); 3–11 (700 mL);and 11–7 (300 mL). Try to avoid the ingestion of largeamounts of fluid immediately before bedtime to prevent theneed to urinate during sleeping hours.

■ Set short-term outcomes that the client can realistically meet.Examples include ingesting a glass of fluid every hour whileawake or a pitcher of water by 12 noon.

■ Identify fluids the client likes and make available a variety ofthose items, including fruit juices, soft drinks, and milk (if al-

lowed). Remember that beverages such as coffee and tea have a diuretic effect, so their consumption should belimited.

■ Help clients to select foods that tend to become liquid at roomtemperature (e.g., gelatin, ice cream, sherbet, custard), if theseare allowed.

■ For clients who are confined to bed, supply appropriate cups,glasses, and straws to facilitate appropriate fluid intake andkeep the fluids within easy reach.

■ Make sure fluids are served at the appropriate temperature: hotfluids hot and cold fluids very cold.

■ Encourage clients when possible to participate in maintainingthe fluid intake record. This assists them to evaluate theachievement of desired outcomes.

■ Be alert to any cultural implications of food and fluids. Somecultures may restrict certain foods and fluids and view othersas having healing properties.

PRACTICE GUIDELINES Helping Clients Restrict Fluid Intake

■ Explain the reason for the restricted intake and how much andwhat types of fluids are permitted orally. Many clients need tobe informed that ice chips, gelatin, and ice cream, for example,are considered fluid.

■ Help the client decide the amount of fluid to be taken witheach meal, between meals, before bedtime, and with medica-tions. For the hospitalized or long-term care client, half the to-tal volume is scheduled during the day shift, when the client ismost active, receives two meals, and most oral medications. Alarge part of the remainder is scheduled for the evening shiftto permit fluids with meals and evening visitors.

■ Identify fluids or fluidlike substances the client likes and makesure that these are provided, unless contraindicated. A clientwho is allowed only 200 mL of fluid for breakfast, for example,should receive the type of fluid the client favors.

■ Set short-term goals that make the fluid restriction more toler-able. For example, schedule a specified amount of fluid at one

or two hourly intervals between meals. Some clients may pre-fer fluids only between meals if the food provided at mealtimehelps relieve thirst.

■ Place allowed fluids in small containers such as a 4-ounce juiceglass to allow the perception of a full container.

■ Periodically offer the client ice chips as an alternative to water,because ice chips when melted are approximately half of thefrozen volume.

■ Provide frequent mouth care and rinses to reduce the thirstsensation.

■ Instruct the client to avoid ingesting or chewing salty or sweetfoods (hard candy or gum), because these foods tend toproduce thirst. Sugarless gum may be an alternative forsome clients.

■ Encourage the client when possible to participate in maintain-ing the fluid intake record.

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take the medication with juice to mask the unpleasant taste andreduce the possibility of gastric distress. Emphasize the impor-tance of taking the medication as prescribed and seeing theirprimary care provider on a regular basis. Because hyperkalemiacan have serious cardiac effects, clients should never increasethe amount of potassium being taken without an order to do so.In addition, inform clients that most salt substitutes containpotassium, so it is important to consult with the primary careprovider before using salt substitutes.

People who ingest insufficient milk and milk products bene-fit from calcium supplements. The recommended daily al-lowance for calcium is 1,000 to 1,500 mg. It is generallyrecommended that postmenopausal women take 1,500 mg ofcalcium per day to reduce the risk of osteoporosis. Long-termuse of corticosteroid drugs can also cause calcium loss from thebone, and calcium supplements may help reduce this loss.Clients who take supplemental calcium need to maintain a fluidintake of at least 2,500 mL per day (unless contraindicated) toreduce the risk of kidney stones, which are commonly com-posed of calcium salts.

Although routine supplements for other electrolytes gener-ally are not recommended, clients who have poor dietary habits,who are malnourished, or who have difficulty accessing or eat-ing fresh fruits and vegetables may benefit from electrolyte sup-plements. A daily multiple vitamin with minerals may achievethe desired goal. People who engage in strenuous activity in awarm environment need to be encouraged to replace water andelectrolytes lost through excessive perspiration by consuming asports drink such as Gatorade or another commercial fluid andelectrolyte solution.

Liquid nutritional supplements are often given to clients whoare malnourished or have poor eating habits. They are used withfrequency in older adults to bolster nutritional status and caloricintake. It is very important to be a “label reader” of the productand to be aware of the contents of the supplement. Some of themare very high in protein and high in potassium, which may becontraindicated in an individual with impaired renal function.

Parenteral Fluid and Electrolyte ReplacementIntravenous (IV) fluid therapy is essential when clients are un-able to take food and fluids orally. It is an efficient and effectivemethod of supplying fluids directly into the intravascular fluidcompartment and replacing electrolyte losses. Intravenous fluidtherapy is usually ordered by the primary care provider. Thenurse is responsible for administering and maintaining the ther-apy and for teaching the client and significant others how tocontinue the therapy at home if necessary.

INTRAVENOUS SOLUTIONS. Intravenous solutions can beclassified as isotonic, hypotonic, or hypertonic. Most IV solu-tions are isotonic, having the same concentration of solutes asblood plasma. Isotonic solutions are often used to restore vas-cular volume. Hypertonic solutions have a greater concentra-tion of solutes than plasma; hypotonic solutions have a lesserconcentration of solutes. Table 52–10 provides examples of IVsolutions and nursing implications.

IV solutions can also be categorized according to their pur-pose. Nutrient solutions contain some form of carbohydrate(e.g., dextrose, glucose, or levulose) and water. Water is sup-plied for fluid requirements and carbohydrate for calories andenergy. For example, 1 L of 5% dextrose provides 170 calories.Nutrient solutions are useful in preventing dehydration and ke-tosis but do not provide sufficient calories to promote woundhealing, weight gain, or normal growth in children. Commonnutrient solutions are 5% dextrose in water (D5W) and 5% dex-trose in 0.45% sodium chloride (dextrose in half-strengthsaline).

Electrolyte solutions contain varying amounts of cations andanions. Commonly used solutions are normal saline (0.9%sodium chloride solution), Ringer’s solution (which containssodium, chloride, potassium, and calcium), and lactatedRinger’s solution (which contains sodium, chloride, potassium,calcium, and lactate). Lactate is metabolized in the liver to formbicarbonate HCO3

�. Saline and balanced electrolyte solutionscommonly are used to restore vascular volume, particularly

TABLE 52–10 Selected Intravenous SolutionsTYPE/EXAMPLES COMMENTS/NURSING IMPLICATIONS

Isotonic Solutions

0.9% NaCl (normal saline)Lactated Ringer’s (a balanced electrolyte solution)5% dextrose in water (D5W)

Hypotonic Solutions

0.45% NaCl (half normal saline)0.33% NaCl (one-third normal saline)

Hypertonic Solutions

5% dextrose in normal saline (D5NS)5% dextrose in 0.45% NaCl (D5 1/2NS)5% dextrose in lactated Ringer’s (D5LR)

Isotonic solutions such as NS and lactated Ringer’s initially remain in the vascularcompartment, expanding vascular volume. Assess clients carefully for signs ofhypervolemia such as bounding pulse and shortness of breath.D5W is isotonic on initial administration but provides free water when dextrose ismetabolized, expanding intracellular and extracellular fluid volumes. D5W is avoidedin clients at risk for increased intracranial pressure (IICP) because it can increasecerebral edema.

Hypotonic solutions are used to provide free water and treat cellular dehydration.These solutions promote waste elimination by the kidneys. Do not administer toclients at risk for IICP or third-space fluid shift.

Hypertonic solutions draw fluid out of the intracellular and interstitial compartmentsinto the vascular compartment, expanding vascular volume. Do not administer toclients with kidney or heart disease or clients who are dehydrated. Watch for signs ofhypervolemia.

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Basilic vein

Cephalic vein

Dorsal venousnetwork

Dorsalmetacarpal veins

B

Cephalic vein

Mediancubitalvein

Accessorycephalic vein

Cephalic vein

Radial vein

Medialantebrachial

vein

Basilic vein

Insertion sitefor PICC

Basilic vein

A

Figure 52-16 ■ Commonly used venipuncture sites of the A, arm; B, hand. A also shows the site used for a peripherally inserted centralcatheter (PICC).

after trauma or surgery. They also may be used to replace fluidand electrolytes for clients with continuing losses, for example,because of gastric suction or wound drainage.

Lactated Ringer’s solution is an alkalinizing solution thatmay be given to treat metabolic acidosis. Acidifying solutions,in contrast, are administered to counteract metabolic alkalosis.Examples of acidifying solutions are 5% dextrose in 0.45%sodium chloride and 0.9% sodium chloride solution.

Volume expanders are used to increase the blood volume fol-lowing severe loss of blood (e.g., from hemorrhage) or loss ofplasma (e.g., from severe burns, which draw large amounts ofplasma from the bloodstream to the burn site). Examples of ex-panders are dextran, plasma, and albumin.

VENIPUNCTURE SITES. The site chosen for venipuncturevaries with the client’s age, the length of time the infusion isto run, the type of solution used, and the condition of veins.For adults, veins in the hand and arm are commonly used; forinfants, veins in the scalp and dorsal foot veins are often used.Larger veins are preferred for infusions that need to be givenrapidly and for solutions that could be irritating (e.g., certainmedications).

The metacarpal, basilic, and cephalic veins are commonlyused for intermittent or continuous infusions (Figure 52-16 ■,B). The ulna and radius act as natural splints at these sites, andthe client has greater freedom of arm movements for activitiessuch as eating. Although the basilic and median cubital veins inthe antecubital space are convenient sites for venipuncture, theyare usually used for blood draws, bolus injections of medica-tion, and insertion sites for a peripherally inserted centralcatheter line (see Figure 52-16 ■, A). See Practice Guidelines forvein selection and general tips for easier IV starts.

When long-term IV therapy or parenteral nutrition is antici-pated or the client is receiving IV medications that are damag-ing to vessels (e.g., chemotherapy), a central venous cathetermay be inserted. Central venous catheters usually are insertedinto the subclavian or jugular vein, with the distal tip of thecatheter resting in the superior vena cava just above the right

atrium (Figure 52-17 ■). They may be inserted at the client’sbedside or, for longer term access, surgically inserted. Subcla-vian central venous catheters permit freedom of movement forambulation; however, there is greater risk of complications, in-cluding hemothorax or pneumothorax, cardiac perforation,thrombosis, and infection. Assess the client closely for manifes-tations such as shortness of breath, chest pain, cough, hypoten-sion, tachycardia, and anxiety after the insertion procedure.

With a peripherally inserted central venous catheter (PICC),the catheter is inserted in the basilic or cephalic vein just aboveor below the antecubital space of the right arm. The tip of thecatheter rests in the superior vena cava. The risk of pneumotho-rax is eliminated with PICC. These catheters frequently are usedfor long-term intravenous access when the client will be man-aging IV therapy at home.

Implantable venous access devices or ports (Figures 52-18 ■

and 52-19 ■ on page 1458) are used for clients with chronic ill-ness who require long-term IV therapy (e.g., intermittent med-ications such as chemotherapy, total parenteral nutrition, and

PRACTICE GUIDELINES Vein Selection

■ Use distal veins of the arm first.■ Use the client’s nondominant arm whenever possible.■ Select a vein that is

a. Easily palpated and feels soft and full.b. Naturally splinted by bone.c. Large enough to allow adequate circulation around the

catheter.■ Avoid using veins that are

a. In areas of flexion (e.g., the antecubital fossa).b. Highly visible, because they tend to roll away from the

needle.c. Damaged by previous use, phlebitis, infiltration, or sclerosis.d. Continually distended with blood, or knotted or tortuous.e. In a surgically compromised or injured extremity (e.g., fol-

lowing a mastectomy), because of possible impaired cir-culation and discomfort for the client.

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frequent blood samples). The device is designed to provide re-peated access to the central venous system, avoiding the traumaand complications of multiple venipunctures. Using local anes-thesia, implantable ports are surgically placed into a small sub-

cutaneous pocket under the skin, usually on the anterior chestnear the clavicle, and no part of the port is exposed. The distalend of the catheter is placed in the subclavian or jugular vein.There are different kinds of implantable venous access devicesand they may be tunneled or nontunneled (Rosenthal, 2005b).

Special precautions need to be taken with all central lines andvenous access ports to ensure asepsis and catheter patency.Nursing care of clients with these devices is outlined in PracticeGuidelines on page 1459.

INTRAVENOUS EQUIPMENT. Because equipment varies ac-cording to the manufacturer, the nurse must become familiarwith the equipment used in each particular agency.

Solution containers are available in various sizes (50, 100,250, 500, or 1,000 mL); the smaller containers are often used toadminister medications. Most solutions are currently dispensedin plastic bags (Figure 52-20 ■). However, glass bottles mayneed to be used if the administered medications are incompati-ble with plastic. Glass bottles require an air vent so that air canenter the bottle and replace the fluid that enters the client’s vein.Some have a tube inside the bottle that serves as a vent; othercontainers without air vents require a vent on the administrationset. Air vents usually have filters to prevent contamination fromthe air that enters the container. Air vents are not required forplastic solution bags, because the bags collapse under atmos-pheric pressure when the solution enters the vein.

It is essential that the solution be sterile and in good condi-tion, that is, clear. Cloudiness, evidence that the container hasbeen opened previously, or leaks indicate possible contamina-tion. Always check the expiration date on the label. Return any

PRACTICE GUIDELINES General Tips for Easier IV Starts

■ Review the client’s medical history. In general, you’ll want toavoid using an arm affected by hemiplegia or with a dialysis ac-cess. Also avoid an arm on the same side as a mastectomy,sites near infections or below previous infiltrations of extrava-sations, and veins affected by phlebitis.

■ Put gravity to work. Dangle the client’s arm over the side of thebed to encourage dependent vein filling.

■ Make sure the client is comfortable. Pain and anxiety stimulatethe sympathetic nervous system and trigger vasoconstrictionand vasovagal reactions. Have the client void before you startthe IV line, make sure he or she is warm enough, and admin-ister pain medication as ordered before the procedure. Helpthe patient into a comfortable prone or semi-Fowler positionfor the IV insertion.

■ Warmth encourages vasodilation. Apply warm compresses tothe site for 10 to 15 minutes before you attempt venipuncture.Unless contraindicated, the client could take a hot shower ordrink warm fluids before IV insertion.

■ Avoid hand veins. Because of the risk of nerve injuries, handveins should be a last choice, especially in older clients whoseskin is very thin.

■ Choose the right device for the ordered therapy. If the orderedIV medication is irritating to veins and therapy is expected tolast more than a few days, consult with the IV nurse or medicalteam to determine whether the client is a candidate for a mid-

line catheter, a peripherally inserted central catheter, or anothertype of central venous access device.

■ Use the smallest gauge cannula that will accommodate thetherapy and allow good venous flow around the catheter tip.For example, for routine hydration or intermittent therapies,use 22- to 27-gauge catheters; for transfusion therapies, 20- to24-gauge; and for therapy for neonates or clients with verysmall, fragile veins, 24- to 27-gauge.

■ Use good body mechanics. Raise the bed or stretcher to acomfortable working height. Sit, when possible, and keep allequipment within reach. Stabilize the client’s hand or arm withyour nondominant arm, tucking it under your forearm if neces-sary to prevent a moving target.

■ Display confidence in your own abilities. When you approachthe client, don’t say, “I’m here to try to start your IV line.” In-stead, confidently state, “I’m here to insert your IV line.”

■ If you miss, offer an honest explanation in a matter-of-fact andfriendly manner. Think about what you can do to improve yournext attempt, and explain what you’ll do differently (if any-thing). Most important, limit your attempts to two. If you’re notsuccessful after two tries, ask another nurse or an anesthesiaprovider to try again a little later.

Note: From “Tailor Your I.V. Insertion Techniques for Special Populations,” byK. Rosenthal, 2005a, Nursing, 35(5), 39. Copyright © 2005 Lippincott, Williams &Wilkins. Reprinted with permission.

Subclavian vein

Catheter

Superior vena cava

A

Figure 52-17 ■ Central venous lines with A, subclavian vein insertion,and B, left jugular insertion.

Catheter

B

Internal jugularveinSubclavian vein

Superiorvena cava

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questionable or contaminated solutions to the pharmacy or IVtherapy department.

Infusion sets usually include an insertion spike, a drip cham-ber, a roller valve or screw clamp, tubing with secondary ports,and a protective cap over the needle adapter (Figure 52-21 ■).The insertion spike is kept sterile and inserted into the solution

container when the equipment is set up and ready to start. Thedrip chamber permits a predictable amount of fluid to be deliv-ered. A commonly used drip chamber is the 10 to 20 drops,which delivers macrodrip per milliliter of solution. This infor-

Figure 52-19 ■ An implantable venous access device (right) and aHuber needle with extension tubing.

Catheter

Lock Self-sealing septum

A

Figure 52-18 ■ An implantable venous access device: A, components;B, the device in place.

Skin

Catheter

Fluid flow

Suture

B

Figure 52-20 ■ A plastic intravenous fluid container.

Protector capfor insertion spike

Spike connector for fluid container

Connector toIV catheter

Drip chamber

Clamp

Clamp

Secondaryport

Secondaryport

Figure 52-21 ■ A standard IV administration set.

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mation is found on the package. There are also 60 drops sets,which deliver microdrip per milliliter of solution. The rollervalve or screw clamp, which compresses the lumen of the tub-ing, controls the rate of the flow. The protective cap over the nee-dle adapter maintains the sterility of the end of the tubing so thatit can be attached to a sterile needle inserted in the client’s vein.

Most infusion sets include one or more injection ports for ad-ministering IV medications or secondary infusions. Needlelesssystems are increasingly used because they reduce the risk ofneedlestick injury and contamination of the intravenous line.There are various types of needleless systems available, includ-ing two-piece prepierced septum and blunt cannula devices,Luer-activated devices, and three-way pressure-activated safetyvalves (Rosenthal, 2003). With each of these needleless sys-tems, a blunt cannula is inserted into a special injection port oradapter on the IV tubing to administer medications or second-ary infusions (Figure 52-22 ■). Many infusion sets include an

in-line filter to trap air, particulate matter, and microbes. A spe-cial infusion set may be required if the IV flow rate will be reg-ulated by an infusion pump.

Catheters and needles are commonly used for intravenousinfusions. Over-the-needle catheters, also known as angio-caths, are commonly used for adult clients. The plasticcatheter fits over a needle used to pierce the skin and vein wall(Figure 52-23 ■). Once inserted into the vein, the needle iswithdrawn and discarded, leaving the catheter in place. IVcatheters allow the client more mobility and rarely infiltrate,that is, become dislodged from the vein and allow fluid to flowinto interstitial spaces.

Safety devices on IV catheters are now common. With the orig-inal over-the-needle catheters, the sharp stylet remained exposeduntil placed in a sharps container. This resulted in needlestick in-juries to nurses. The 2000 Needlestick Safety and Prevention Actrequires the use of needle saftey devices to prevent exposure to

PRACTICE GUIDELINES Caring for Clients with a Venous Access Device

■ On insertion, document the date; the site; the brand, gauge,and catheter length; the location of the catheter tip (verified byx-ray); the length of the external segment; and client teaching.Do not use the access device until correct placement has beenverified by x-ray.

SITE CARE■ Use strict aseptic technique when caring for central lines and

long-term venous access devices.■ The frequency of dressing changes may vary from every 3 to 7

days, depending on the site. Dressings also should be changedwhen loose or soiled.

■ Assess the site for any redness, swelling, tenderness, ordrainage. Compare the length of the external portion of thecatheter with its documented length to assess for possible dis-placement. Obtain a chest x-ray to determine the catheter tip’sposition if in doubt. Report and document any positionchanges or signs of infection.

■ Follow agency protocol for cleaning solutions and types ofdressings. Isopropyl alcohol or a combination of alcohol andacetone followed by povidone-iodine are commonly used toclean the port site.

■ Before accessing the port, clean an area 2 inches in diameteraround the site with an alcohol-acetone solution on a sterilecotton swab. Start at the center of the port site, moving out-ward with a firm, circular motion. Follow with povidone-iodinesolution. Allow the site to air dry.

■ Secure the catheter, and cover the entry site and external por-tion of the catheter with an occlusive dressing.

■ Provide routine care of the incision site for the implant deviceuntil it is healed. Once it heals, no care is necessary when theport is idle.

CATHETER CARE AND FLUSHING■ Change the catheter cap as indicated by protocol, usually every

3 to 7 days.■ Flush the port with normal saline, a heparin flush solution (10

units/mL or 100 units/mL), or as agency protocol recom-mends for the specific type of port being used. After infusingmedications or solutions, again flush the port with saline be-fore using heparinized saline.

■ Using a 10-mL syringe, flush the catheter with a solution of 10units of heparin after each use. The frequency of flushes be-tween uses may vary from every 12 hours to once a week orless, depending on the type of catheter.

■ Remember to flush all lumens for multiple-lumen catheters.■ Use a specially designed needle to access an implanted port.

A needle with a 90-degree angle is generally used for infusionsbecause it is easier to stabilize and more comfortable for theclient. Stabilizing the port between the thumb and index fingerof the nondominant hand, insert the needle through the cen-ter of the port until the resistance of the platform is felt.

■ To remove the needle after a treatment, again stabilize the portand use even pressure to withdraw the needle. Maintain posi-tive pressure by withdrawing the needle as the last milliliter offlush solution is being instilled.

■ Flush idle implanted ports with heparinized saline in accor-dance with agency protocol or at least every 8 weeks.

TEACHINGProvide clients with the following instructions:■ Do not allow anyone to take a blood pressure on the arm in

which a PICC line is inserted.■ Wear a medic-alert tag or bracelet if the device is to be in place

for a long period.■ For a PICC, you do not need to restrict activities, except do not

immerse the arm in water. Showering is allowed if the site andcatheter are covered by an occlusive dressing.

■ For an implanted venous port there are no activity restrictions,but remember that the port or catheter tip can become dis-lodged. Signs of a dislodged catheter tip include pain in theneck or ear on the affected side, swishing or gurgling sounds,or palpitations. Free movement of the port, swelling, or diffi-culty accessing the port may indicate port dislodgment. Notifythe primary care provider should any of these occur or if symp-toms of infection develop.

Note: From “Getting a Line on Central Vascular Access Devices,” by S. Masoorli &T. Angeles, 2002, Nursing, 32(4), pp. 36–43. Copyright © 2005 Lippincott,Williams & Wilkins. Reprinted with permission.

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bloodborne pathogens (Wilburn, 2004). The safety devices for IVcatheters vary. They can be either an active safety device which re-quires activation by the nurse or a passive safety device where thesafety feature is automatically activated after the sytlet is removedfrom the catheter.

Butterfly, or wing-tipped, needles with plastic flaps attached tothe shaft are sometimes used (Figure 52-24 ■). The flaps are heldtightly together to hold the needle securely during insertion; afterinsertion, they are flattened against the skin and secured with tape.

IV poles are used to hang the solution container. Somepoles are attached to hospital beds; others stand on the floor

Figure 52-22 ■ Cannulae used to connect the tubing of additive sets to primary infusions: A, threaded-lock cannula; B, lever-lock cannula.(Photographs reprinted courtesy of (BD) Becton, Dickinson and Company and courtesy of Baxter Healthcare Corporation. All rights reserved.)

A B

Introducer needle Cannula

Translucent catheter hub

Preview chamber

Flashback chamber

Filter vent

Luer lock tabs

Finger guard

Needle bevel position indicator

Short bevel introducer needle

Needle heel

Tapered catheter tip

Figure 52-23 ■ Schematic of an over-the-needle catheter.

Cap for needle

Plasticadapter

Tubing

Stem

Wings

Figure 52-24 ■ Schematic of a butterfly needle with adapter.

or hang from the ceiling. In the home, plant hangers or robehooks (even kitchen cabinet knobs or an S-hook over the topof a door) may be used to hang solution containers. Theheight of most poles is adjustable. The higher the solutioncontainer, the greater the force of the solution as it enters theclient and the faster the rate of flow.

STARTING AN INTRAVENOUS INFUSION. Although the pri-mary care provider is responsible for ordering IV therapy forclients, nurses initiate, monitor, and maintain the prescribedIV infusion. This is true not only in hospitals and long-termcare facilities but increasingly in community-based settingssuch as clinics and clients’ homes.

Before starting an infusion, the nurse determines the following:

■ The type and amount of solution to be infused■ The exact amount (dose) of any medications to be added to a

compatible solution■ The rate of flow or the time over which the infusion is to be

completed

If solutions are prepared by the pharmacy or another depart-ment, the nurse must verify that the solution supplied exactlymatches that which the primary care provider ordered.

Understanding the purpose for the infusion is as importantas assessing the client. For example, the nurse may questionan order for 5% dextrose in water at 150 mL/h if the clienthas peripheral edema and other signs of fluid overload.

To perform venipuncture and start an intravenous infusion,see Skill 52-1.

Med

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Appl

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SKILL 52-1

STARTING AN INTRAVENOUS INFUSION

Before preparing the infusion, the nurse first verifies the primarycare provider’s order indicating the type of solution, the amount to

be administered, the rate of flow of the infusion, and any clientallergies (e.g., to tape or povidone-iodine).

PURPOSES■ To supply fluid when clients are unable to take in an adequate

volume of fluids by mouth■ To provide salts and other electrolytes needed to maintain elec-

trolyte balance

■ To provide glucose (dextrose), the main fuel for metabolism■ To provide water-soluble vitamins and medications■ To establish a lifeline for rapidly needed medications

ASSESSMENTAssess the following:

■ Vital signs (pulse, respiratory rate, and blood pressure) for base-line data

■ Skin turgor

■ Allergy to latex (e.g., tourniquet), tape, or iodine■ Bleeding tendencies■ Disease or injury to extremities■ Status of veins to determine appropriate venipuncture site

PLANNINGPrior to initiating the IV infusion, consider how long the client is likelyto have the IV, what kinds of fluids will be infused, and what medica-tions the client will be receiving or is likely to receive. These factorsmay affect the choice of vein and catheter size.

DelegationThis procedure is done by a registered nurse and, in many states,by a licensed pratical nurse or licensed vocational nurse. Checkthe state’s nurse practice act. Due to the use of sterile technique,intravenous infusion therapy is not delegated to unlicensed as-sistive personnel (UAP). UAP may care for clients receiving IVtherapy, and the nurse must ensure that the UAP knows how toperform routine tasks such as bathing and positioning withoutdisturbing the IV. The UAP should also know what complicationsor adverse signs, such as leakage, should be reported to thenurse. In some states a licensed vocational nurse with special IVtherapy training may start intravenous infusions.

Equipment■ Infusion set■ Sterile parenteral solution■ IV pole■ Adhesive or nonallergenic tape■ Clean gloves■ Tourniquet■ Antiseptic swabs■ Antiseptic ointment (check agency policy)■ Intravenous catheter; see Variation at the end of this procedure

for a butterfly (winged-tip) needle■ Sterile gauze dressing or transparent occlusive dressing■ Arm splint, if required■ Towel or pad■ Electronic infusion device or pump (The nurse decides what de-

vice is needed as appropriate to the client’s condition.)

IMPLEMENTATIONPreparation1. Prepare the client.

● Prior to performing the procedure, introduce self and verifythe client’s identity using agency protocol. Explain the proce-dure to the client. A venipuncture can cause discomfort fora few seconds, but there should be no discomfort while thesolution is flowing. Use a doll to demonstrate for children,and explain the procedure to the parents. Clients often wantto know how long the process will last. The primary careprovider’s order may specify the length of time of the infu-sion, for example, 3,000 mL over 24 hours.

● Unless initiating IV therapy is urgent, provide any scheduledcare before establishing the infusion to minimize movementof the affected limb during the procedure. Moving the limb af-ter the infusion has been established could dislodge thecatheter.

● Make sure that the client’s clothing or gown can be removedover the IV apparatus if necessary. Some agencies providespecial gowns that open over the shoulder and down thesleeve for easy removal.

PerformancePerform hand hygiene.1. Open and prepare the infusion set.

● Remove tubing from the container and straighten it out.● Slide the tubing clamp along the tubing until it is just below

the drip chamber to facilitate its access.● Close the clamp.● Leave the ends of the tubing covered with the plastic caps

until the infusion is started. Rationale: This will maintain thesterility of the ends of the tubing.

2. Spike the solution container.● Remove the protective cover from the entry site of the bag.● Remove the cap from the spike and insert the spike into the

insertion site of the bag or bottle. � Follow the manufac-turer’s instructions.

3. Apply a medication label to the solution container if a medica-tion is added.● In many agencies, medications and labels are applied in the

pharmacy; if they are not, apply the label upside down onthe container. Rationale: The label is applied upside downso it can be read easily when the container is hanging up.


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STARTING AN INTRAVENOUS INFUSION continued

SKIL

L 52

-1

4. Apply a timing label on the solution container.● The timing label may be applied at the time the infusion is

started. Follow agency practice. See later discussion of regu-lating infusion flow rates and Figure 52-26.

5. Hang the solution container on the pole.● Adjust the pole so that the container is suspended about

1 m (3 ft) above the client’s head. Rationale: This height isneeded to enable gravity to overcome venous pressure andfacilitate flow of the solution into the vein.

6. Partially fill the drip chamber with solution.● Squeeze the chamber gently until it is half full of solution. �

7. Prime the tubing.● Remove the protective cap and hold the tubing over a con-

tainer. Maintain the sterility of the end of the tubing and thecap.

● Release the clamp and let the fluid run through the tubing un-til all bubbles are removed. Tap the tubing if necessary withyour fingers to help the bubbles move. Rationale: The tub-ing is primed to prevent the introduction of air into the client.

Air bubbles smaller than 0.5 mL usually do not cause problems inperipheral lines.

● Reclamp the tubing and replace the tubing cap, maintainingsterile technique.

● For caps with air vents, do not remove the cap when prim-ing this tubing. The flow of solution through the tubing willcease when the cap is moist with one drop of solution.

● If an infusion control pump, electronic device, or controller isbeing used, follow the manufacturer’s directions for insertingthe tubing and setting the infusion rate.

8. Perform hand hygiene again just prior to client contact.9. Select the venipuncture site.

● Use the client’s nondominant arm, unless contraindicated(e.g., mastectomy, fistula for dialysis). Identify possiblevenipuncture sites by looking for veins that are relativelystraight, not sclerotic or tortuous, and avoid venous valves.The vein should be palpable, but may not be visible, espe-cially in clients with dark skin. Consider the catheter length;look for a site sufficiently distal to the wrist or elbow that thetip of the catheter will not be at a point of flexion. Rationale:Sclerotic veins may make initiating and maintaining the IVdifficult. Joint flexion increases the risk of irritation of veinwalls by the catheter.

● Check agency protocol about shaving if the site is veryhairy. Shaving is not usually recommended because of thepotential for microabrasions which can increase the riskof infection.

● Place a towel or bed protector under the extremity to protectlinens (or furniture if in the home).

10. Dilate the vein.● Place the extremity in a dependent position (lower than the

client’s heart). Rationale: Gravity slows venous return anddistends the veins. Distending the veins makes it easier toinsert the needle properly.

● Apply a tourniquet firmly 15 to 20 cm (6 to 8 in.) above thevenipuncture site. � Explain that the tourniquet will feeltight. Rationale: The tourniquet must be tight enough to ob-struct venous flow but not so tight that it occludes arterialflow. Obstructing arterial flow inhibits venous filling. If a ra-dial pulse can be palpated, the arterial flow is not obstructed.

Use the tourniquet on only one client. This avoids cross-contamination to other clients.

� Inserting the spike.Photographer: Elena Dorfman

Pull this endto untie

A

B

� Applying a tourniquet.� Squeezing the drip chamber.Photographer: Elena Dorfman

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● Holding the over-the-needle catheter at a 15- to 30-degreeangle with bevel up, insert the catheter through the skin andinto the vein. Sudden lack of resistance is felt as the needleenters the vein. Jabbing, stabbing, or quick thrusting shouldbe avoided because it may cause rupture of delicate veins(Phillips, 2005).

● Once blood appears in the lumen of the needle or you feelthe lack of resistance, lower the angle of the catheter until itis almost parallel with the skin, and advance the needle andcatheter approximately 0.5 to 1 cm (about 1/4 in.) farther.Holding the needle portion steady, advance the catheter un-til the hub is at the venipuncture site. The exact techniquedepends on the type of device used. Rationale: Thecatheter is advanced to ensure that it, and not just the metalneedle, is in the vein. The exact technique depends on thetype of catheter used.

● Release the tourniquet.● Put pressure on the vein proximal to the catheter to elimi-

nate or reduce blood oozing out of the catheter. Stabilize thehub with thumb and index finger of the nondominant hand.

● Remove the protective cap from the distal end of the tubingand hold it ready to attach to the catheter, maintaining thesterility of the end.

● Carefully remove the needle, engage the needle safety device,and attach the end of the infusion tubing to the catheter hub.

● Initiate the infusion.13. Tape the catheter.

● Tape the catheter by the “U” method or according to themanufacturer’s instructions. Using three strips of adhesivetape, each about 7.5 cm (3 in.) long:a. Place one strip, sticky side up, under the catheter’s hub.b. Fold each end over so that the sticky sides are against the

skin. �c. Place the second strip, sticky side down, over the catheter

hub.d. Place the third strip, sticky side down, over the tubing hub.

14. Dress and label the venipuncture site and tubing according toagency policy.● Unless there is an allergy, a sterile transparent occlusive

dressing is applied. � This permits assessment of the site


● If the vein is not sufficiently dilated:a. Massage or stroke the vein distal to the site and in the di-

rection of venous flow toward the heart. Rationale: Thisaction helps fill the vein.

b. Encourage the client to clench and unclench the fist.Rationale: Contracting the muscles compresses the dis-tal veins, forcing blood along the veins and distendingthem.

c. Lightly tap the vein with your fingertips. Rationale:Tapping may distend the vein.

● If the preceding steps fail to distend the vein so that it is pal-pable, remove the tourniquet and wrap the extremity in awarm, moist towel for 10 to 15 minutes. Rationale: Heat di-lates superficial blood vessels, causing them to fill. Then re-peat step 10.

11. Put on clean gloves and clean the venipuncture site.Rationale: Gloves protect the nurse from contamination bythe client’s blood.● Clean the skin at the site of entry with a topical antiseptic swab

(e.g., 2% chlorhexidine, or alcohol). Some institutions mayuse an anti-infective solution such as povidone-iodine (checkagency protocol). Check for allergies to iodine or shellfish be-fore cleansing skin with Betadine or iodine products.

● Use a circular motion, moving from the center outward forseveral inches. Rationale: This motion carries microorgan-isms away from the site of entry.

● Permit the solution to dry on the skin. Povidone-iodine shouldbe in contact with the skin for 1 minute to be effective.

12. Insert the catheter and initiate the infusion.● If desired and permitted by policy, inject 0.05 mL of 1% li-

docaine intradermally over the site where you plan to insertthe IV needle. Allow 5 to 10 seconds for the anesthetic totake effect. Transdermal analgesic creams (e.g., ELA-Max,EMLA) may also be used, depending on policy. Allow 30minutes for the transdermal analgesic to take effect.

● Use the nondominant hand to pull the skin taut below theentry site. Rationale: This stabilizes the vein and makes theskin taut for needle entry. It can also make initial tissue pen-etration less painful.

� Taping an intravenous catheter by the “U” method.� Cover insertion site with transparent dressing.(Patrick Watson)

SKILL 52-1


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SKIL

L 52

-1

without disturbing the dressing. This type of dressing can beleft on for 72 hours, then changed.

● Discard the tourniquet. Remove soiled gloves and discardappropriately.

● Loop the tubing and secure it with tape. Rationale: Loopingand securing the tubing prevent the weight of the tubing orany movement from pulling on the needle or catheter.

● Label the dressing with the date and time of insertion, type,gauge of catheter used, and your initials. �

15. Ensure appropriate infusion flow.● Apply a padded arm board to splint the joint, as needed.● Adjust the infusion rate of flow according to the order.

16. Label the IV tubing.● Label the tubing with the date and time of attachment and

your initials. � This labeling may also be done when the in-fusion is started. Rationale: The tubing is labeled to ensure

that it is changed at regular intervals (i.e., every 24 to 96hours according to agency policy).

17. Document relevant data, including assessments.● Record the start of the infusion on the client’s chart. Some

agencies provide a special form for this purpose. Include thedate and time of the venipuncture; amount and type of solu-tion used, including any additives (e.g., kind and amount ofmedications); container number; flow rate; type, length, andgauge of the needle or catheter; venipuncture site, how manyattempts were made, and location of each attempt; the typeof dressing applied; and the client’s general response.

SAMPLE DOCUMENTATION

1/15/2008 0600 Inserted 20 gauge angiocath in (L) forearmon first attempt. IV infusing at 125 mL/hour. Explained reasonfor IV. Stated understanding. ______________A. Luis, RN

VARIATION: INSERTING A BUTTERFLY (WINGED-TIP) NEEDLE

■ Hold the needle, pointed in the direction of the blood flow, at a 30-degree angle, with the bevel up, and pierce the skin beside the veinabout 1 cm (1/2 in.) below the site planned for piercing the vein.

■ Once the needle is through the skin, lower the needle so that itis almost parallel with the skin. Rationale: Lowering the needlereduces the chances of puncturing both sides of the vein.

Follow the course of the vein, and pierce one side of the vein. Sud-den lack of resistance can be felt as blood enters the needle.

■ When blood flows back into the needle tubing, insert the nee-dle to its hub.

■ Release the tourniquet, attach the infusion, and initiate flow asquickly as possible. Rationale: Attaching the tubing quickly pre-vents blood from clotting and obstructing the needle.

■ Secure the butterfly needle by taping it securely by the crisscross(chevron) method. � Place a small gauze square under theneedle, if required. Rationale: The gauze keeps the needle inposition in the vein.

� Label IV site with date, time, size of catheter, and initials.(Patrick Watson)

I.V. SET–__ HRS.–ONLYSTART DATE________HR._____DISCARD DATE______HR._____R.N. INITIAL_________________

729/11

9/1408000800

LA

� Tubing labeled with date, time of attachment, and nurse’s initials.Also shown is a preprinted label.

Photographer: Elena Dorfman

Needle in vein

Tape

Tubing

� Taping the butterfly needle by the chevron method.

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EVALUATIONEvaluate the following:

■ Skin status at IV site (warm temperature and absence of pain,redness, and swelling)

■ Status of dressing

■ IV flow rate consistent with that ordered■ Ability to perform self-care activities; understanding of any mo-

bility limitations■ Vital signs compared to baseline level

REGULATING AND MONITORING INTRAVENOUS INFUSIONS.Orders for IV infusions may take several forms: “3,000 mL over24 hours”; “1,000 mL every 8 hours × 3 bags”; “125 mL/h un-til oral intake is adequate.” The nurse initiating the IV calculatesthe correct flow rate, regulates the infusion, and monitors theclient’s responses. Unless an infusion control device is used, thenurse manually regulates the drops per minute of flow using theroller clamp to ensure that the prescribed amount of solutionwill be infused in the correct time span. If the flow is incorrect,problems such as hypervolemia, hypovolemia, or inadequatemedication administration can result.

The number of drops delivered per milliliter of solutionvaries with different brands and types of infusion sets. Thisrate, called the drip factor (sometimes called the drop factor),generally is printed on the package of the infusion set. Macro-drops commonly have drop factors of 10, 12, 15, or 20drops/mL; the drop factor for microdrip is always 60drops/mL (Figure 52-25 ■).

To calculate flow rates, the nurse must know the volume offluid to be infused and the specific time for the infusion. Twocommonly used methods of indicating flow rates are designat-ing the number of milliliters to be administered in 1 hour (mL/h)and the number of drops to be given in 1 minute (gtt/min). Be-cause l milliliter of fluid displaces 1 cubic centimeter of space,the volume to be infused in the first method may also be desig-nated as cubic centimeters per hour (cc/h).

Milliliters per Hour. Hourly rates of infusion can be calculatedby dividing the total infusion volume by the total infusion time

Figure 52-25 ■ Infusion set spikes and drip chambers: nonventedmacrodrip, vented macrodrip, nonvented microdrip.

in hours. For example, if 3,000 mL is infused in 24 hours, thenumber of milliliters per hour is

3,000 mL (total infusion volume) � 125 mL/h24 h (total infusion time)

Nurses need to check infusions at least every hour to ensure thatthe indicated milliliters per hour have infused and that IV patencyis maintained. A strip of adhesive marking the exact time and/oramount to be infused may be taped to the solution container. Someagencies make premarked labels available (Figure 52-26 ■).

Drops per Minute. The nurse initiating and monitoring an in-fusion must regulate the drops per minute to ensure that the pre-scribed amount of solution will infuse. Drops per minute arecalculated by the following formula:

Drops per minute �Total infusion volume � drop factor

Total time of infusion in minutes

If the requirements are 1,000 mL in 8 hours and the drip factoris 20 drops/mL, the drops per minute should be

1,000 mL � 208 � 60 min (480 min)

� 41 drops/min

Approximating this rate as 40 drops/min, the nurse regulates thedrops per minute by tightening or releasing the IV tubing clampand counting the drops for 15 seconds, then multiplying thatnumber by 4 (e.g., 10 drops/15 sec).

A number of factors influence flow rate (see Box 52–8).

Figure 52-26 ■ Timing label on an intravenous container. The first timemarked (0900 hours) would be correct for a bag hung at 0800 hourswith a rate of 100 mL per hour.Photographer: Elena Dorfman

SKILL 52-1

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BOX 52—8 Factors Influencing Flow Rates

■ The position of the forearm. Sometimes a change in the positionof the client’s arm decreases flow. Slight pronation, supination, ex-tension, or elevation of the forearm on a pillow can increase flow.

■ The position and patency of the tubing. Tubing can be obstructedby the client’s weight, a kink, or a clamp closed too tightly. Theflow rate also diminishes when part of the tubing dangles belowthe puncture site.

■ The height of the infusion bottle. Elevating the height of the infusionbottle a few inches can speed the flow by creating more pressure.

■ Possible infiltration or fluid leakage. Swelling, a feeling of coldness,and tenderness at the venipuncture site may indicate infiltration.

■ Relationship of the size of the angiocath to the vein. A catheterthat is too large may impede the infusion flow.

Figure 52-27 ■ The Dial-A-Flo in-line device.Photographer: Elena Dorfman

Figure 52-28 ■ An intravenous infusion pump.Photographer: Jenny Thomas

Figure 52-29 ■ Programmable infusion pumps.(Courtesy of ALARIS Medical Systems, Inc., San Diego, California.)

DEVICES TO CONTROL INFUSIONS. A number of devices areused to control the rate of an infusion. Electronic infusion devices(EIDs) regulate the infusion rate at preset limits. They also havean alarm that is triggered when the solution in the IV bag is low,when there is air in the tubing, or when the tubing is not highenough. The Dial-A-Flo in-line device (Figure 52-27 ■) is a reg-ulator that controls the amount of fluid to be administered. Hos-pitals may stock the Dial-A-Flo for use in situations where apump is not required, but prevention of fluid overload is impor-tant. It is preset at the volume to be infused and can be attached atthe time the infusion is set up or when the tubing is changed. An-other variation is a volume-control set, or Volutrol, which is usedif the volume of fluid administered is to be carefully controlled.The set, which holds a maximum of 100 mL of solution, is at-tached below the solution container, and the drip chamber isplaced below the set. Volume-control sets are frequently used inpediatric settings, where the volume administered is critical.

CLINICAL ALERTA flow rate control device should be used when administering IV fluid toelderly or pediatric clients. Both of these age groups are especially at riskfor complications of fluid overload, which can occur with rapid infusionof IV fluids. ■

An infusion pump (Figures 52-28 ■ and 52-29 ■) deliversfluids intravenously by exerting positive pressure on the tubingor on the fluid. In situations where the fluid flow is unrestricted,the pump pressure is comparable to that of gravity flow. How-ever, if restrictions develop (increased venous resistance), thepump can maintain the fluid flow by increasing the pressure ap-plied to the fluid.

A controller, by contrast, operates solely by gravitationalforce. The delivery pressure depends on the height of the con-tainer in relation to the venipuncture site. The container must beat least 76 cm (30 in.) above the venipuncture site for a con-troller to work. A controller does not have the ability to addpressure to the line and to overcome resistances to fluid flow.

Skill 52-2 outlines the steps involved in monitoring an intra-venous infusion.

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SKILL 52-2

MONITORING AN INTRAVENOUS INFUSION

PURPOSES■ To maintain the prescribed flow rate■ To prevent complications associated with IV therapy


■ Appearance of infusion site; patency of system■ Type of fluid being infused and rate of flow■ Response of the client

PLANNINGReview the type of equipment used outside the client’s room. Readall appropriate materials and confirm the type of tubing, controller, orpump being used.

DelegationThis procedure should be done by the nurse because it is an im-portant part of assessment and complications may occur.

IMPLEMENTATIONPreparation1. Gather the pertinent data.

● From the primary care provider’s order, determine the typeand sequence of solutions to be infused.

● Determine the rate of flow and infusion schedule.

Performance1. Ensure that the correct solution is being infused.

● If the solution in incorrect, slow the rate of flow to a mini-mum to maintain the patency of the catheter. Rationale:Stopping the infusion may allow a thrombus to form in theIV catheter. If this occurs, the catheter must be removed andanother venipuncture performed before the infusion can beresumed.

● Change the solution to the correct one. Document and re-port the error according to agency protocol.

2. Observe the rate of flow every hour.● Compare the rate of flow regularly, for example, every hour,

against the infusion schedule. Rationale: Infusions that areoff schedule can be harmful to a client.

● If the rate is too fast, slow it so that the infusion will be com-pleted at the planned time. Rationale: Solution administeredtoo quickly may cause a significant increase in circulatingblood volume (which is about 6 L in an adult). Hypervolemiamay result in pulmonary edema and cardiac failure. Assessthe client for manifestations of hypervolemia and its compli-cations, including dyspnea; rapid, labored breathing; cough;crackles (rales) in the lung bases; tachycardia; and boundingpulses.

● If the rate is too slow, check agency practice. Some agenciespermit nursing personnel to adjust a rate of flow by a speci-fied amount. Adjustments above this rate require a primarycare provider’s order. Rationale: Solution that is adminis-tered too slowly can supply insufficient fluid, electrolytes, ormedication for a client’s needs.

● If the rate of flow is 150 mL/h or more, check the rate of flowmore frequently, for example, every 15 to 30 minutes.

3. Inspect the patency of the IV tubing and catheter.● Observe the position of the IV solution. If it is less than 1 m

(3 ft) above the IV site, readjust it to the correct height of thepole. Rationale: If the IV bag/bottle is too low, the solutionmay not flow into the vein because there is insufficient grav-

itational pressure to overcome the pressure of the bloodwithin the vein.

● Observe the drip chamber. If it is less than half full, squeezethe chamber to allow the correct amount of fluid to flow in.

● Open the drip regulator and observe for a rapid flow of fluidfrom the solution container into the drip chamber. Thenpartially close the drip regulator to reestablish the pre-scribed rate of flow. Rationale: Rapid flow of fluid into thedrip chamber indicates patency of the IV line. Closing thedrip regulator to the prescribed rate of flow prevents fluidoverload.

● Inspect the tubing for pinches or kinks or obstructions toflow. Arrange the tubing so that it is lightly coiled and underno pressure. Sometimes the tubing becomes caught underthe client’s body and the weight blocks the flow.

● Observe the position of the tubing. If it is dangling below thevenipuncture, coil it carefully on the surface of the bed.Rationale: The solution may not flow upward into the veinagainst the force of gravity.

● Lower the solution container below the level of the infusionsite and observe for a return flow of blood from the vein.Rationale: A return flow of blood indicates that the needleis patent and in the vein. Blood returns in this instance be-cause venous pressure is greater than the fluid pressure inthe IV tubing. Absence of blood return may indicate that theneedle is no longer in the vein or that the tip of the catheteris partially obstructed by a thrombus, the vein wall, or avalve in the vein.

● Determine whether the bevel of the catheter is blockedagainst the wall of the vein. If it is blocked, pull back gently,turn it slightly, or carefully raise or lower the angle of inser-tion slightly, using a sterile gauze pad underneath to protectthe skin and change the position of the catheter bevel.

● If there is leakage, locate the source. If the leak is at thecatheter connection, tighten the tubing into the catheter. Ifthe leak cannot be stopped, slow the infusion as much aspossible without stopping it, and replace the tubing with anew sterile set. Estimate the amount of solution lost, if it wassubstantial.

4. Inspect the insertion site for fluid infiltration.● When an IV needle becomes dislodged from the vein, fluid

flows into interstitial tissues, causing swelling. This is known


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MONITORING AN INTRAVENOUS TRANSFUSION continued

SKIL

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as infiltration and is manifested by localized swelling, cool-ness, pallor, and discomfort at the IV site.

● If an infiltration is present, stop the infusion and remove thecatheter. Restart the infusion at another site.

● Apply a warm compress to the site of the infiltration. Ration-ale: Warmth promotes comfort and vasodilation, facilitatingabsorption of the fluid from interstitial tissues.

5. If the infiltration involves a vesicant drug, it is called extravasa-tion and other measures may be indicated. Extravasated vesi-cant drugs can cause severe tissue injury or destruction. Theextravasation of a vesicant drug should be considered an emer-gency (Hadaway, 2004).● Stop the infusion immediately. Disconnect the tubing as

close to the catheter hub as possible and attempt to aspirateany drug remaining in the hub. If an injectable antidote isavailable, the catheter should remain in place.

● The primary care provider should be notified and if ordered,the antidote administered.

● The affected arm should be elevated and depending on thedrug, heat or cold therapy should be implemented.

6. If infiltration is not evident but the infusion is not flowing, de-termine whether the needle is dislodged from the vein.● Gently pinch the IV tubing adjacent to the needle site. This

will cause blood to flow (flash back) into the tubing if theneedle is in the vein.

● Use a sterile syringe of saline to withdraw fluid from the portnear the venipuncture site. If blood does not return, discon-tinue the intravenous solution.

7. Inspect the insertion site for phlebitis (inflammation of a vein).● Inspect and palpate the site at least every 8 hours. Phlebitis

can occur as a result of injury to a vein, for example, because

of mechanical trauma or chemical irritation. Chemical injuryto a vein can occur from intravenous electrolytes (especiallypotassium and magnesium) and medications. The clinicalsigns are redness, warmth, and swelling at the intravenoussite and burning pain along the course of a vein.

● If phlebitis is detected, discontinue the infusion, and applywarm compresses to the venipuncture site. Do not use thisinjured vein for further infusions.

8. Inspect the intravenous site for bleeding.● Oozing or bleeding into the surrounding tissues can occur

while the infusion is freely flowing but is more likely to occurafter the needle has been removed from the vein.

● Observation of the venipuncture site is extremely importantfor clients who bleed readily, such as those receiving antico-agulants.

9. Teach the client ways to maintain the infusion system, for example:● Avoid sudden twisting or turning movements of the arm with

the needle or catheter.● Avoid stretching or placing tension on the tubing.● Try to keep the tubing from dangling below the level of the

needle.● Notify a nurse if

a. The flow rate suddenly changes or the solution stopsdripping.

b. The solution container is nearly empty.c. There is blood in the IV tubing.d. Discomfort or swelling is experienced at the IV site.

10. Document all relevant information.


■ Amount of fluid infused according to the schedule■ Intactness of IV system

■ Appearance of IV site (e.g., dry, tissue infiltration, discomfort)■ Urinary output compared to urinary intake■ Tissue turgor; specific gravity of urine■ Vital signs and lung sounds compared to baseline data

CHANGING INTRAVENOUS CONTAINERS, TUBING, ANDDRESSINGS. Intravenous solution containers are changedwhen only a small amount of fluid remains in the neck of thecontainer and fluid still remains in the drip chamber. However,

all IV bags should be changed every 24 hours, regardless ofhow much solution remains, to minimize the risk of contami-nation. IV tubing is changed every 48 to 96 hours, dependingon agency protocol, as is the site dressing. Skill 52-3 provides

SKIL

L 52

-3

CHANGING AN INTRAVENOUS CONTAINER, TUBING, AND DRESSING

PURPOSES■ To maintain the flow of required fluids■ To maintain sterility of the IV system and decrease the incidence

of phlebitis and infection


■ Presence of fluid infiltration, bleeding, or phlebitis at IV site■ Allergy to tape or iodine■ Infusion rate and amount absorbed

■ Blockages in IV system■ Appearance of the dressing for integrity, moisture, and need for

change■ The date and the time of the previous dressing change

■ To maintain patency of the IV tubing■ To prevent infection at the IV site and the introduction of mi-

croorganisms into the bloodstream

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CHANGING AN INTRAVENOUS CONTAINER, TUBING, AND DRESSING continued

■ Timing label■ Sterile gauze square for positioning the needle

For the Dressing

■ Clean gloves■ Sterile 2-in. × 2-in. or 4-in. × 4-in. gauze or transparent dressing■ Adhesive remover■ Chlorhexidine swabs■ Alcohol swabs■ Tape■ Towel

PLANNINGReview primary care provider’s orders for changes in fluid administration.

DelegationThis procedure includes assessment of the IV site and should becompleted by a registered nurse. In many states, licensed voca-tional nurses with IV certification may complete the procedure.

Equipment■ Container with the correct kind and amount of sterile solution■ Administration set, including sterile tubing and drip chamber

IMPLEMENTATIONPreparation1. Obtain the correct solution container.

● Read the label of the new container.● Verify that you have the correct solution, correct client, cor-

rect additives (if any), and correct dose (number of bags ortotal volume ordered).

Performance1. Perform hand hygiene.2. Set up the intravenous equipment with the new container and

label all. See Skill 52-1, steps 1 to 8.● Apply a timing label to the container.● Prime the tubing.● Label the tubing as shown in Figure � in Skill 52-1.

3. Prepare the IV needle or catheter, tape, and the dressing equip-ment near the client.● Prepare strips of tape as needed for the type of needle or

catheter. For the butterfly needle, two or three strips of1.25-cm (1/2-in.) tape are needed. For a catheter, threestrips of 1.25-cm (1/2-in.) tape are needed. These will beused later to secure the needle or catheter without cover-ing the insertion site.

● Hang the pieces of tape from the edge of a table. Rationale:This places the tape in readiness for use without disruptingthe adhesive. Ensure that the table is clean to avoid contam-inating the tape.

● Open all equipment: swabs, dressing and adhesive band-age, and ointment. Rationale: This facilitates access to sup-plies after gloves are donned.

● Place a towel under the extremity. Rationale: This preventssoiling of bed linens.

● Apply clean gloves.4. Remove the soiled dressing and all tape, except the tape hold-

ing the catheter or IV needle in place.● Remove tape and gauze from the old dressing one layer at

a time. Rationale: This prevents dislodgment of the catheteror needle in case tubing becomes entangled between lay-ers of dressing.

● Remove adhesive dressings in the direction of the client’shair growth when possible. Rationale: This minimizes dis-comfort when adhesive is removed from the skin.

● Discard the used dressing materials in the appropriatecontainer.

5. Assess the IV site.● Inspect the IV site for the presence of infiltration or inflam-

mation. Rationale: Inflammation or infiltration necessitatesremoval of the IV needle or catheter to avoid further traumato the tissues.

● Go to step 6, or discontinue and relocate the IV site if indi-cated. See Skills 52-1 and 52-4.

6. Disconnect the used tubing.● Place a sterile swab under the hub of the catheter.

Rationale: This absorbs any leakage that might occur whenthe tubing is disconnected.

● Clamp the tubing. With the fourth or fifth finger of the non-dominant hand, apply pressure to the vein above the end ofthe catheter. Rationale: This helps prevent blood from com-ing out of the needle during the change of tubing.

● Holding the hub of the catheter with the thumb and indexfinger of the nondominant hand, loosen the tubing with thedominant hand, using a twisting, pulling motion. Rationale:Holding the catheter firmly but gently maintains its positionin the vein.

● Remove the used IV tubing.● Place the end of the tubing in the basin or other receptacle.

7. Connect the new tubing, and reestablish the infusion.● Continue to hold the catheter and grasp the new tubing with

the dominant hand.● Remove the protective tubing cap and, maintaining sterility,

insert the tubing end securely into the needle hub. Twist it tosecure it.

● Open the clamp to start the solution flowing.8. Remove the tape securing the needle or catheter.

● When removing this tape and while cleaning the site, stabi-lize the needle or catheter hub with one hand. Rationale:This prevents inadvertent dislodgment of the needle orcatheter.

9. Clean the IV site.● Start with adhesive remover to remove adhesive residue.

Rationale: Removal of adhesive residue facilitates adher-ence of the new dressing.

● Then, using chlorhexidine swabs or alcohol swabs, clean thesite, beginning at the catheter or needle and cleaning out-ward in a 2-in. diameter. Rationale: Cleaning in this man-ner prevents contamination of the IV site from bacteria onthe peripheral skin areas. Antiseptics reduce the number of

SKILL 52-3


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guidelines for changing an IV solution container, tubing, andthe IV site dressing.

When an IV infusion is no longer necessary to maintain theclient’s fluid intake or to provide a route for medication admin-istration, the infusion is either discontinued and the catheter re-

moved or the catheter is left in place and converted to a salineor heparin lock. Guidelines for discontinuing an IV infusion orconverting the catheter to a lock are outlined in Skills 52-4 and52-5, respectively.

CHANGING AN INTRAVENOUS CONTAINER, TUBING, AND DRESSING continued

SKIL

L 52

-3

microorganisms present at the site, thus reducing the risk ofinfection.

● Follow agency protocol about cleaning procedures.10. Retape the needle or catheter.

● For a butterfly needle, apply strips of tape to the wings ofthe butterfly using the crisscross (chevron) method (Figure � in Skill 52-1).

● For a catheter; apply the tape using the U method (Figure � in Skill 52-1).

● Apply a sterile transparent dressing over the site.● Remove gloves.

11. Label the dressing and secure IV tubing.

● Place the date and time of the dressing change and your ini-tials either on the label provided or directly over the top ofthe dressing.

● Secure IV tubing with additional tape as required.12. Regulate the rate of flow of the solution according to the order

on the chart.13. Document all relevant information.

● Record the change of the solution container, tubing, and/ordressing in the appropriate place on the client’s chart. Alsorecord the fluid intake according to agency practice. Recordthe number of the container if the containers are numberedat the agency. Also record your assessments.


■ Status of IV site■ Patency of IV system■ Accuracy of flow

SKIL

L 52

-4

DISCONTINUING AN INTRAVENOUS INFUSION

PURPOSE■ To discontinue an intravenous infusion when the therapy is complete or when the IV site needs to be changed


■ Appearance of the venipuncture site■ Any bleeding from the infusion site

■ Amount of fluid infused■ Appearance of IV catheter

PLANNINGReview the primary care provider’s orders.

DelegationThis procedure should be done by a registered nurse. In manystates, licensed vocational nurses may initiate and discontinue IVtherapy.

Equipment■ Clean gloves■ Dry or antiseptic-soaked swabs, according to agency practice■ Small sterile dressing and tape

IMPLEMENTATIONPerformance1. Prepare the equipment.

● Clamp the infusion tubing. Rationale: Clamping the tubingprevents the fluid from flowing out of the needle onto theclient or bed.

● Loosen the tape at the venipuncture site while holding theneedle firmly and applying countertraction to the skin.Rationale: Movement of the needle can injure the vein and

cause discomfort to the client. Countertraction preventspulling the skin and causing discomfort.

● Put on clean gloves and hold a sterile gauze above thevenipuncture site.

2. Withdraw the needle or catheter from the vein.● Withdraw the needle or catheter by pulling it out along the

line of the vein. Rationale: Pulling it out in line with the veinavoids injury to the vein.

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DISCONTINUING AN INTRAVENOUS INFUSION continued

● Immediately apply firm pressure to the site, using sterilegauze, for 2 to 3 minutes. Rationale: Pressure helps stopthe bleeding and prevents hematoma formation.

● Hold the client’s arm above the body if any bleeding persists.Rationale: Raising the limb decreases blood flow to the area.

3. Examine the catheter removed from the client.● Check the catheter to make sure it is intact. Rationale: If a

piece of tubing remains in the client’s vein it could movecentrally (toward the heart or lungs) and cause seriousproblems.

● Report a broken catheter to the nurse in charge or primarycare provider immediately.

● If a broken piece can be palpated, apply a tourniquet abovethe insertion site. Rationale: Application of a tourniquet de-

creases the possibility of the piece moving until a primarycare provider is notified.

4. Cover the venipuncture site.● Apply the sterile dressing. Rationale: The dressing continues

the pressure and covers the open area in the skin, prevent-ing infection.

● Discard the IV solution properly, if infusions are being discon-tinued, and discard the used supplies appropriately.

5. Document all relevant information.● Record the amount of fluid infused on the intake and output

record and on the chart, according to agency practice. In-clude the container number, type of solution used, time ofdiscontinuing the infusion, and the client’s response.


■ Appearance of the venipuncture site■ The pulse

■ Respirations, skin color, edema, sputum, cough, and urine output■ How the person feels physically and psychologically

SKILL 52-5

CHANGING AN INTRAVENOUS CATHETER TO AN INTERMITTENT INFUSION LOCK

PURPOSE■ To permit IV administration of medications or fluids on an intermittent basis


■ Patency of the IV catheter■ Appearance of the site (evidence of inflammation or infiltration)

PLANNINGReview the primary care provider’s order.

■ A specific order may be written to convert an intravenous accessto a heparin or saline lock. The order also may be implied, forexample, IV fluids are to be discontinued but the client has or-ders for an IV antibiotic every 6 hours or is receiving analgesicsintravenously.

DelegationDue to the need for sterile technique and technical complexity,this procedure is not delegated to UAP. UAP may care for clientswith such devices, and the nurse must ensure that the UAPknows what complications or adverse signs should be reportedto the nurse.

Equipment■ Intermittent infusion cap or device■ Clean gloves■ Sterile 2-in. × 2-in. or 4-in. × 4-in. gauze■ Sterile saline for injection (without preservative) or heparin flush

solution (10 units/mL or 100 units/mL) in a prefilled syringe, a3-mL syringe with a needleless infusion device

■ Isopropyl alcohol wipe■ Tape■ Clean emesis basin


● Prior to performing the procedure, introduce self and verifythe client’s identity using agency protocol. Explain the proce-dure to the client and the reason for leaving the IV catheterin place. Changing an IV to a heparin or saline lock shouldcause no discomfort other than that associated with remov-ing tape from the IV tubing.

Performance1. Prepare the equipment.

● Perform hand hygiene.● Assess the IV site (if visible) and determine the patency of

the catheter (see Skill 52-2). If the catheter is not fully patentor there is evidence of phlebitis or infiltration, discontinuethe catheter and establish a new IV site.

SKILL 52-4

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Blood TransfusionsIntravenous fluids can be effective in restoring intravascular(blood) volume; however, they do not affect the oxygen-carrying capacity of the blood. When red and white bloodcells, platelets, or blood proteins are lost because of hemor-rhage or disease, it may be necessary to replace these compo-nents to restore the blood’s ability to transport oxygen andcarbon dioxide, to clot, to fight infection, and to keep extra-cellular fluid within the intravascular compartment. A bloodtransfusion is the introduction of whole blood or blood com-ponents into the venous circulation.

BLOOD GROUPS. Human blood is commonly classified intofour main groups (A, B, AB, and O). The surface of an indi-vidual’s red blood cells contains a number of proteins known

as antigens that are unique for each person. Many blood anti-gens have been identified, but the antigens A, B, and Rh arethe most important in determining blood group or type. Be-cause antigens promote agglutination or clumping of bloodcells, they are also known as agglutinogens. The A antigen oragglutinogen is present on the RBCs of people with bloodgroup A, the B antigen is present in people with blood groupB, and both A and B antigens are found on the RBC surface inpeople with group AB blood. Neither antigen is present in peo-ple with group O blood.

Preformed antibodies to RBC antigens are present in theplasma; these antibodies are often called agglutinins. Peoplewith blood group A have B antibodies (agglutinins); A antibod-ies are present in people with blood group B; and people withblood group O have antibodies to both A and B antigens. Peo-ple with group AB blood do not have antibodies to either A or Bantigens (Table 52–11). When blood is transfused, the blood

CHANGING AN INTRAVENOUS CATHETER TO AN INTERMITTENT INFUSION LOCK continued

SKIL

L 52

-5

● Expose the IV catheter hub and loosen any tape that is hold-ing the IV tubing in place or that will interfere with insertionof the intermittent infusion plug into the catheter.

● Clamp the IV tubing to stop the flow of IV fluid.● Open the gauze pad and place it under the IV catheter hub.● Open the alcohol wipe and intermittent infusion plug, leav-

ing the plug in its sterile package.2. Remove the IV tubing and insert the intermittent infusion plug

into the IV catheter.● Put on gloves.● Stabilize the IV catheter with your nondominant hand and

use the little finger to place slight pressure on the vein abovethe end of the catheter. Twist the IV tubing adapter to loosenit from the IV catheter and remove it, placing the end of thetubing in a clean emesis basin.

● Pick up the intermittent infusion plug from its package andremove the protective sleeve from the male adapter, main-taining its sterility. Insert the plug into the IV catheter, twist-ing it to seat it firmly or engage the Luer lock.

3. Instill saline or heparin solution per agency policy. Rationale:Saline or heparin are used to maintain patency of the IVcatheter when fluids are not infusing through the catheter.

4. Tape the intermittent infusion plug in place using a chevron orU method. Rationale: Tape provides added security to pre-vent the infusion plug from coming out of the intravenouscatheter. It also promotes comfort, preventing the plug fromcatching on clothing or bedding.

5. Teach the client how to maintain the lock.● Avoid manipulating the catheter or infusion plug and protect

it from catching on clothing or bedding. A gauze bandagesuch as Kerlix or Kling may be wrapped over the plug whenit is not in use to protect it.

● Cover the site with an occlusive dressing when showering;avoid immersing the site.

● Flush the catheter with saline or heparin solution as directed.● Notify the nurse or primary care provider if the plug or

catheter comes out; if the site becomes red, inflamed, orpainful; or if any drainage or bleeding occurs at the site.

6. Document all relevant information.


■ Patency of the catheter■ Appearance of the site■ Ease of flushing

CULTURALLY COMPETENT CAREBlood and Blood Products

■ Jehovah’s Witnesses do not receive blood or blood products.Blood volume expanders are acceptable if they are not deriva-tives of blood.

■ Christian Scientists do not ordinarily use blood or blood products.

Note: From Transcultural Concepts in Nursing Care (4th ed.) (pp. 470, 481), byM. M. Andrews and J. S. Boyle, 2003, Philadelphia: Lippincott Williams & Wilkins.Reprinted with permission.

TABLE 52–11 The Blood Groups with TheirConstituent Agglutinogens and AgglutininsBLOOD RBC ANTIGENS PLASMA ANTIBODIESTYPES (AGGLUTINOGENS) (AGGLUTININS)A A BB B AAB A and B —O — A and B

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group of the donor and recipient must match to avoid an anti-gen-antibody reaction and destruction (hemolysis) of RBCs.

RHESUS (RH) FACTOR. The Rh factor antigen is present onthe RBCs of approximately 85% of the people in the UnitedStates. Blood that contains the Rh factor is known as Rh-positive (Rh�); when it is not present the blood is said to beRh-negative (Rh�). In contrast to the ABO blood groups, Rh�

blood does not naturally contain Rh antibodies. However, onexposure to blood containing Rh factor (e.g., an Rh� mothercarrying a fetus with Rh� blood, or transfusion of Rh� bloodinto a client who is Rh�), Rh antibodies develop. Subsequentexposures to Rh� blood place the client at risk for anantigen–antibody reaction and hemolysis of RBCs.

BLOOD TYPING AND CROSSMATCHING. To avoid transfus-ing incompatible red blood cells, both blood donor and recipi-ent are typed and their blood crossmatched. Blood typing isdone to determine the ABO blood group and Rh factor status.This test is also performed on pregnant women and neonates toassess for possible intrauterine exposure of either to an incom-patible blood type (particularly Rh factor incompatibilities).

Because blood typing only determines the presence of themajor ABO and Rh antigens, crossmatching also is necessaryprior to transfusion to identify possible interactions of minorantigens with their corresponding antibodies. RBCs from thedonor blood are mixed with serum from the recipient; a reagent(Coombs’ serum) is added, and the mixture is examined for vis-ible agglutination. If no antibodies to the donated RBCs arepresent in the recipient’s serum, agglutination does not occurand the risk of transfusion reaction is small.

SELECTION OF BLOOD DONORS. Screening of blood donorsis rigorous. Criteria have been established to protect the donorfrom possible ill effects of donation and to protect the recipi-ent from exposure to diseases transmitted through the blood.Blood donors are unpaid volunteers. Potential donors are

eliminated by a history of hepatitis, HIV infection (or risk fac-tors for HIV infection), heart disease, most cancers, severeasthma, bleeding disorders, or convulsions. Donation may bedeferred for people with malaria or who have been exposed tomalaria or hepatitis or in situations of pregnancy, surgery, ane-mia, high or low blood pressure, and certain drugs.

BLOOD AND BLOOD PRODUCTS FOR TRANSFUSION. Mostclients do not require transfusion of whole blood. It is more com-mon for clients to receive a transfusion of a particular blood com-ponent specific to their individual needs. Table 52–12 lists someof the common blood products that may be transfused.

TRANSFUSION REACTIONS. Transfusion of ABO- or Rh-incompatible blood can result in a hemolytic transfusion reac-tion with destruction of the transfused RBCs and subsequentrisk of kidney damage or failure. Other forms of transfusionreaction also may occur, including febrile, allergic, circulatoryoverload, and sepsis. Because the risk of an adverse reactionis high when blood is transfused, clients must be frequentlyand carefully assessed before and during transfusion. Many re-actions become evident within 5 to 15 minutes of initiating thetransfusion but they can develop any time during a transfu-sion; clients are closely monitored during the initial period ofthe transfusion. Stop the transfusion immediately if signs of areaction develop. Possible transfusion reactions, their clinicalsigns, and nursing implications are listed in Table 52–13.

ADMINISTERING BLOOD. Special precautions are necessarywhen administering blood.

When a transfusion is ordered, obtain the blood from the bloodbank just before starting the transfusion. Do not store the blood inthe refrigerator on the nursing unit; lack of temperature controlmay damage the blood. Once blood or a blood product is removedfrom the refrigerator, there is a limited amount of time to adminis-ter it (e.g., packed RBCs should not hang for more than 4 hours af-ter being removed from the refrigerator). Follow agency policies

TABLE 52–12 Blood Products for TransfusionPRODUCT USEWhole blood

Packed red blood cells (PRBCs)

Autologous red blood cells

Platelets

Fresh frozen plasma

Albumin and plasma protein fractionClotting factors and cryoprecipitate

Not commonly used except for extreme cases of acute hemorrhage. Replaces blood volume andall blood products: RBCs, plasma, plasma proteins, fresh platelets, and other clotting factors.Used to increase the oxygen-carrying capacity of blood in anemias, surgery, and disorders withslow bleeding. One unit of PRBCs has the same amount of oxygen-carrying RBCs as a unit ofwhole blood (Rosenthal, 2004, p. 23). One unit raises hematocrit by approximately 2% to 3%.Used for blood replacement following planned elective surgery. Client donates blood forautologous transfusion 4–5 weeks prior to surgery.Replaces platelets in clients with bleeding disorders or platelet deficiency. Fresh platelets mosteffective. Each unit should increase the average adult client’s platelet count by about 5,000platelets/microliter (Rosenthal, 2004, p. 24).Expands blood volume and provides clotting factors. Does not need to be typed andcrossmatched (contains no RBCs). Each unit will increase the level of any clotting factor by 2% to3% in the average adult (Rosenthal, 2004, p. 26).Blood volume expander; provides plasma proteins.Used for clients with clotting factor deficiencies. Each provides different factors involved in theclotting pathway; cryoprecipitate also contains fibrinogen.

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for verifying that the unit is correct for the client. The U.S. Foodand Drug Administration (FDA) requires blood products to havebar codes to allow for scanning and machine-readable informationon blood and blood component container labels to help reducemedication errors (FDA, 2004). Blood is usually administeredthrough a #18- to #20-gauge intravenous needle or catheter; usinga smaller needle may slow the infusion and damage blood cells (al-though a smaller gauge needle may be necessary for small childrenor clients with small, fragile veins). AY-type blood transfusion setwith an in-line or add-on filter is used when administering blood(Figure 52-30 ■). One arm of the administration set connects to theblood; normal saline (0.9% NaCl) is attached to the other arm ofthe Y-type set. Saline is used to prime the set and flush the needlebefore administering blood. It also provides a means to keep thevein open should a transfusion reaction occur. No other IV solu-

tions should be administered with blood; they may cause the bloodcells to clump or cause clotting. Atransfusion should be completedwithin 4 hours of initiation. The risk of sepsis increases if bloodhangs for a longer period. Blood tubing is changed after every 4 to6 units per agency policy; new intravenous tubing is used follow-ing a transfusion.

CLINICAL ALERTNormal saline should always be used when giving a blood transfusion.If the client has an infusion of dextrose, stop that infusion and flush theline with saline prior to initiating the transfusion. Solutions other thansaline can cause damage to the blood components. ■

To initiate, maintain, and terminate a blood transfusion, seeSkill 52-6.

TABLE 52–13 Transfusion Reactions

REACTION: CAUSE CLINICAL SIGNS NURSING INTERVENTION*

Hemolytic reaction:incompatibility betweenclient’s blood and donor’sblood

Febrile reaction: sensitivity ofthe client’s blood to whiteblood cells, platelets, orplasma proteins

Allergic reaction (mild):sensitivity to infused plasmaproteins

Allergic reaction (severe):antibody–antigen reaction

Circulatory overload: bloodadministered faster than thecirculation can accommodate

Sepsis: contaminated bloodadministered

Chills, fever, headache,backache, dyspnea, cyanosis,chest pain, tachycardia,hypotension

Fever; chills; warm, flushedskin; headache; anxiety;muscle pain

Flushing, itching, urticaria,bronchial wheezing

Dyspnea, chest pain,circulatory collapse, cardiacarrest

Cough, dyspnea, crackles(rales), distended neck veins,tachycardia, hypertension

High fever, chills, vomiting,diarrhea, hypotension

1. Discontinue the transfusion immediately.NOTE: When the transfusion is discontinued, the blood tubing must beremoved as well. Use new tubing for the normal saline infusion.

2. Maintain vascular acess with normal saline, or according to agencyprotocol.

3. Notify the primary care provider immediately.4. Monitor vital signs.5. Monitor fluid intake and output.6. Send the remaining blood, bag, filter, tubing, a sample of the client’s

blood, and a urine sample to the laboratory.1. Discontinue the transfusion immediately.2. Give antipyretics as ordered.3. Notify the primary care provider.4. Keep the vein open with a normal saline infusion.1. Stop or slow the transfusion, depending on agency protocol.2. Notify the primary care provider.3. Administer medication (antihistamines) as ordered.1. Stop the transfusion.2. Keep the vein open with normal saline.3. Notify the primary care provider immediately.4. Monitor vital signs. Administer cardiopulmonary resuscitation if needed.5. Administer medications and/or oxygen as ordered.1. Place the client upright, with feet dependent.2. Stop or slow the transfusion.3. Notify the primary care provider.4. Administer diuretics and oxygen as ordered.1. Stop the transfusion.2. Keep the vein open with a normal saline infusion.3. Notify the primary care provider.4. Administer IV fluids, antibiotics.5. Obtain a blood specimen from the client for culture.6. Send the remaining blood and tubing to the laboratory.

*Nurses should follow the agency’s protocol regarding interventions. These may vary among agencies.

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Adapter

Y-Injection site

Slide clamp

Main flow rateclamp

Blood filterchamber

Drip chamber

Upperclamps

Spikes

To salinesolution

Toblood

Figure 52-30 ■ Schematic of a Y-set for blood administration.

SKILL 52-6

INITIATING, MAINTAINING, AND TERMINATING A BLOOD TRANSFUSION USING A Y-SET

PURPOSES■ To restore blood volume after severe hemorrhage■ To restore the oxygen-carrying capacity of the blood

■ To provide plasma factors, such as antihemophilic factor (AHF)or factor VIII, or platelet concentrates, which prevent or treatbleeding


■ Clinical signs of reaction (e.g., sudden chills, fever, nausea, itch-ing, rash, low back pain, dyspnea)

■ Manifestations of hypervolemia■ Status of infusion site■ Any unusual symptoms

PLANNING

■ Verify the primary care provider order for transfusion.■ Verify client consent and obtain baseline data before the trans-

fusion.■ Verify that a signed consent form was obtained.■ Assess vital signs for baseline data, including blood pressure,

pulse, respiratory rate and depth, and temperature.

■ Determine any known allergies or previous adverse reactions toblood.

■ Note specific signs related to the client’s pathology and the rea-son for the transfusion. For example, for an anemic client, notethe hemoglobin and hematocrit levels.


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INITIATING, MAINTAINING, AND TERMINATING A BLOOD TRANSFUSION USING A Y-SET continued

SKIL

L 52

-6 DelegationDue to the need for sterile technique and technical complexity,blood transfusion is not delegated to UAP. The nurse must en-sure that the UAP knows what complications or adverse signscan occur and should be reported to the nurse.

Equipment■ Blood product■ Blood administration set

■ 250 mL normal saline for infusion■ IV pole■ Venipuncture set containing a #18- to #20-gauge needle or

catheter (if one is not already in place) or, if blood is to be ad-ministered quickly, a larger catheter

■ Chlorhexidine solution■ Alcohol swabs■ Tape■ Clean gloves


● Prior to performing the procedure, introduce self and verifythe client’s identity using agency protocol.

● Explain the procedure and its purpose to the client. Instructthe client to report promptly any sudden chills, nausea, itch-ing, rash, dyspnea, back pain, or other unusual symptoms.

● If the client has an intravenous solution infusing, checkwhether the needle and solution are appropriate to admin-ister blood. The preferred needle size is from #18 to #20gauge, and the solution must be normal saline. Dextrose(which causes lysis of RBCs), Ringer’s solution, medicationsand other additives, and hyperalimentation solutions are in-compatible. Refer to step 5 below if the infusing solution isnot compatible.

● If the client does not have an IV solution infusing, checkagency policies. In some agencies an infusion must be run-ning before the blood is obtained from the blood bank. Inthis case, you will need to perform a venipuncture on a suit-able vein (see Skill 52-1) and start an IV infusion of normalsaline.

Performance1. Obtain the correct blood component for the client.

● Check the primary care provider’s order with the requisition.● Check the requisition form and the blood bag label with a lab-

oratory technician or according to agency policy. Specifically,check the client’s name, identification number, blood type (A, B, AB, or O) and Rh group, the blood donor number, andthe expiration date of the blood. Observe the blood for abnor-mal color, RBC clumping, gas bubbles, and extraneous mate-rial. Return outdated or abnormal blood to the blood bank.

● With another nurse (most agencies require an RN), comparethe laboratory blood record witha. The client’s name and identification number.b. The number on the blood bag label.c. The ABO group and Rh type on the blood bag label.

● If any of the information does not match exactly, notify thecharge nurse and the blood bank. Do not administer blooduntil discrepancies are corrected or clarified.

● Sign the appropriate form with the other nurse according toagency policy.

● Make sure that the blood is left at room temperature for no more than 30 minutes before starting the transfusion.Rationale: RBCs deteriorate and lose their effectiveness af-ter 2 hours at room temperature. Lysis of RBCs releasespotassium into the bloodstream, causing hyperkalemia.

Agencies may designate different times at which the bloodmust be returned to the blood bank if it has not been started.Rationale: As blood components warm, the risk of bacterialgrowth also increases. If the start of the transfusion is unex-pectedly delayed, return the blood to the blood bank. Do notstore blood in the unit refrigerator. Rationale: The tempera-ture of unit refrigerators is not precisely regulated and theblood may be damaged.

2. Verify the client’s identity according to agency protocol.● Check the client’s arm band for name and ID number. Do

not administer blood to a client without an arm band.3. Set up the infusion equipment.

● Ensure that the blood filter inside the drip chamber is suit-able for whole blood or the blood components to be trans-fused. Attach the blood tubing to the blood filter, if necessary.Rationale: Blood filters have a surface area large enough toallow the blood components through easily but are de-signed to trap clots.

● Put on gloves.● Close all clamps on the Y-set: the main flow rate clamp and

both Y-line clamps.● Using a twisting motion, insert the piercing pin (spike) into a

container of 0.9% saline solution.● Hang the container on the IV pole about 1 m (36 in.) above

the venipuncture site.4. Prime the tubing.

● Open the upper clamp on the normal saline tubing andsqueeze the drip chamber until it covers the filter and one-third of the drip chamber above the filter.

● Tap the filter chamber to expel any residual air in the filter.● Remove the adapter cover at the tip of the blood adminis-

tration set.● Open the main flow rate clamp, and prime the tubing with

saline.● Close both clamps.

5. Start the saline solution.● If an IV solution incompatible with blood is infusing, stop the

infusion and discard the solution and tubing according toagency policy.

● Attach the blood tubing primed with normal saline to the in-travenous catheter.

● Open the saline and main flow rate clamps and adjust theflow rate. Use only the main flow rate clamp to adjust the rate.

● Allow a small amount of solution to infuse to make surethere are no problems with the flow or with the venipunc-ture site. Rationale: Infusing normal saline before initiatingthe transfusion also clears the IV catheter of incompatiblesolutions or medications.

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6. Prepare the blood bag.● Invert the blood bag gently several times to mix the cells with

the plasma. Rationale: Rough handling can damage thecells.

● Expose the port on the blood bag by pulling back the tabs. �● Insert the remaining Y-set spike into the blood bag.● Suspend the blood bag.● Close the upper clamp below the IV saline solution on the

Y-set.● Open the clamp on the blood arm of the Y-set and prime the

tubing.7. Establish the blood transfusion.

● The blood will run into the saline-filled drip chamber. If nec-essary, squeeze the drip chamber to reestablish the liquidlevel with drip chamber one-third full. (Tap the filter to expelany residual air within the filter.)

● Readjust the flow rate with the main clamp.8. Observe the client closely for the first 5 to 10 minutes.

● Run the blood slowly for the first 15 minutes at 20 drops perminute.

● Note adverse reactions, such as chilling, nausea, vomiting,skin rash, or tachycardia. Rationale: The earlier a transfusionreaction occurs, the more severe it tends to be. Identifyingsuch reactions promptly helps to minimize the conse-quences.

● Remind the client to call a nurse immediately if any unusualsymptoms are felt during the transfusion.

● If any of these reactions occur, report these to the nurse incharge and take appropriate nursing action (see Table 52–13).

9. Document relevant data.● Record starting the blood, including vital signs, type of blood,

blood unit number, sequence number (e.g., no. 1 of threeordered units), site of the venipuncture, size of the needle,and drip rate.


1/21/2008 1400 1 unit of PRBCs (#65234) hung to be in-fused over 3 hours. IV site in (L) forearm with 19 G an-giocath. VS taken (see transfusion record). Informed tocontact nurse if begins to experience any discomfort dur-ing transfusion. Stated he would use the call light.____________________________C. Jones, RN.

10. Monitor the client.● Fifteen minutes after initiating the transfusion, check the vi-

tal signs of the client. If there are no signs of a reaction, es-tablish the required flow rate. Most adults can toleratereceiving one unit of blood in 1 1/2 to 2 hours. Do not trans-fuse a unit of blood for longer than 4 hours.

● Assess the client including vital signs every 30 minutes ormore often, depending on the health status, until 1 hourpost-transfusion. If the client has a reaction and the blood isdiscontinued, send the blood bag and tubing to the labora-tory for investigation of the blood.

11. Terminate the transfusion.● Put on clean gloves.

● If no infusion is to follow, clamp the blood tubing and re-move the needle. If another transfusion is to follow, clampthe blood tubing and open the saline infusion arm. Blood ad-ministration sets are changed within 24 hours or after 4 to 6units of blood per agency protocol.

● If the primary IV is to be continued, flush the maintenanceline with saline solution. Disconnect the blood tubing systemand reestablish the intravenous infusion using new tubing.Adjust the drip to the desired rate. Often a normal saline orother solution is kept running in case of delayed reaction tothe blood.

● Discard the administration set according to agency practice.Needles should be placed in a labeled, puncture-resistantcontainer designed for such disposal. Blood bags and ad-ministration sets should be bagged and labeled before be-ing sent for decontamination and processing. See agencypolicy.

● Remove gloves.● Again monitor vital signs.

12. Follow agency protocol for appropriate disposition of the bloodbag.● On the requisition attached to the blood unit, fill in the time

the transfusion was completed and the amount transfused.● Attach one copy of the requisition to the client’s record and

another to the empty blood bag.● Return the blood bag and requisition to the blood bank.

13. Document relevant data.● Record completion of the transfusion, the amount of blood ab-

sorbed, the blood unit number, and the vital signs. If the pri-mary intravenous infusion was continued, record connecting it.Also record the transfusion on the IV flow sheet and I & Orecord.


1/21/2008 1410 C/O feeling warm, headache and back-ace. Skin flushed. Temp. 102.6, BP. 140/90, P. 112, R. 28.Approximately 50–100 cc infused. Infusion stopped.Tubing changed and NS infusing at 15 cc/hr. Dr. Rileynotified. ______________________C. Jones, RN

� Exposing the port on the blood bag by pulling back the tabs.


SKILL 52-6

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EvaluatingUsing the overall goals identified in the planning stage of main-taining or restoring fluid balance, maintaining or restoring pul-monary ventilation and oxygenation, maintaining or restoringnormal balance of electrolytes, and preventing associated risksof fluid, electrolyte, and acid–base imbalances, the nurse col-lects data to evaluate the effectiveness of interventions. Exam-ples of desired outcomes for the identified goals are found inIdentifying Nursing Diagnoses, Outcomes, and Interventions onpages 1451 and 1452.

If desired outcomes are not achieved, the nurse, client, andsupport person if appropriate need to explore the reasons before

modifying the care plan. For example, if the outcome “Urineoutput is greater than 1,300 mL per day and within 500 mL of in-take” is not achieved, questions to be considered might include

■ Have other outcome measures for the goal of achieving fluidbalance been met?

■ Does the client understand and comply with planned fluid intake?■ Is all urinary output being measured?■ Are unusual or excessive amounts of fluid being lost by an-

other route (e.g., gastric suction, excessive perspiration,fever, rapid respiratory rate, wound drainage)?

■ Are prescribed medications being taken or administered asordered?


SKIL

L 52

-6


■ Changes in vital signs or health status■ Presence of chills, nausea, vomiting, or skin rash

NURSING CARE PLAN Deficient Fluid Volume

ASSESSMENT DATA NURSING DIAGNOSIS DESIRED OUTCOMES*

Nursing AssessmentMerlyn Chapman, a 27-year-old sales clerk, reports weakness,malaise, and flu-like symptoms for 3–4 days. Although thirsty, sheis unable to tolerate fluids because of nausea and vomiting, andshe has liquid stools 2–4 times per day.

Deficient Fluid Volume relatedto nausea, vomiting, and diar-rhea as evidenced by de-creased urine output, increasedurine concentration, weakness,fever, decreased skin/tongueturgor, dry mucous mem-branes, increased pulse rate,and decreased blood pressure

Electrolyte & Acid/Base Bal-ance [0600] as evidenced bynot compromised:• Serum electrolytes• Muscle strength

Fluid Balance [0601] as evi-denced by not compromised:• 24-hour intake and outputbalance• Urine specific gravity• Blood pressure, pulse, andbody temperature• Skin turgor• Moist mucous membranes

Physical Examination

Height: 160 cm (5′3′′)Weight: 66.2 kg (146 lb)Mild fever: 38.6°C (101.5°F)Pulse: 86 BPMRespirations: 24/minuteScant urine outputBP: 102/84 mm HgDry oral mucosa, furrowedtongue, cracked lips

Diagnostic Data

Urine specific gravity: 1.035Serum sodium 155 mEq/LSerum potassium 3.2 mEq/LChest x-ray negative

NURSING INTERVENTIONS*/SELECTED ACTIVITIES RATIONALE

Electrolyte Management: Hypokalemia [2007]

Obtain specimens for analysis of altered potassium levels (e.g.,serum and urine potassium) as indicated.

Administer prescribed supplemental potassium (PO, NG, or IV)per policy.

Monitor for neurologic and neuromuscular manifestations of hy-pokalemia (e.g., muscle weakness, lethargy, altered level of con-sciousness).

Urine and serum analysis provides information about extracellu-lar levels of potassium. There is no practical way to measure in-tracellular K�.

Low potassium levels are dangerous and Mrs. Chapman mayrequire supplements.

Potassium is a vital electrolyte for skeletal and smooth muscleactivity.

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NURSING CARE PLAN Deficient Fluid Volume continued

NURSING INTERVENTIONS*/SELECTED ACTIVITIES RATIONALE

Monitor for cardiac manifestations of hypokalemia (e.g., hypoten-sion, tachycardia, weak pulse, rhythm irregularities).

Many cardiac rhythm disorders can result from hypokalemia. It iscritical to monitor cardiac function with hypokalemia.

Electrolyte Management: Hypernatremia [2004]

Obtain specimens for analysis of altered sodium levels (e.g.,serum and urine sodium, urine osmolality, and urine specific grav-ity) as indicated.

Provide frequent oral hygiene.

Monitor for neurologic and neuromuscular manifestations of hy-pernatremia (e.g., lethargy, irritability, seizures, and hyperreflexia).

Monitor for cardiac manifestations of hypernatremia (e.g., tachy-cardia, orthostatic hypotension).

Urine analysis provides information about retention or loss ofsodium and the ability of the kidneys to concentrate or dilute urinein response to fluid changes.

Oral mucous membranes become dry and sticky due to loss offluid in the interstitial spaces.

Hypernatremia, as a result of low fluid volume, creates a hyper-tonic vascular space, which causes water to move out of the cells,including brain cells. This accounts for neurologic symptoms.

The heart responds to a loss of fluid by increasing the heart rate tocompensate with an increase in cardiac output. Low fluid volumeleads to a fall in blood pressure.

Fluid Management [4120]

Weigh daily and monitor trends.

Maintain accurate I & O record.

Monitor vital signs as appropriate.

Give fluids as appropriate.

Administer IV therapy as prescribed.

Weight helps to assess fluid balance.

Accurate records are critical in assessing the patient’s fluid balance.

Vital sign changes such as increased heart rate, decreased bloodpressure, and increased temperature indicate hypovolemia.

As her nausea decreases encourage her oral intake of fluids as tol-erated, again to replace lost volume.

Mrs. Chapman has signs of severe fluid volume deficit. She willprobably require intravenous replacement of fluid. This is especiallytrue because her oral intake is limited because of nausea andvomiting.

EVALUATION

Outcomes met. Mrs. Chapman remained hospitalized for 48 hours. She required fluid replacement of a total of 5 liters. Her blood pressureincreased to 122/74, pulse rate decreased to a resting level of 74, and respirations decreased to 12/minute. Her urine output increased asthe fluid was replaced and was adequate at > 0.5 mL/kg/hour by the time of discharge. The urine specific gravity was 1.015. Lab work onthe day of discharge was: K�: 3.8 and Na�: 140. She had elastic skin turgor and moist mucous membranes. She was taking oral fluids andwas able to discuss symptoms of deficient fluid volume that would necessitate her calling her health care provider.

* The NOC # for desired outcomes and the NIC # for nursing interventions and seleted activities are listed in brackets following the appropriate out-come or intervention. Outcomes, interventions, and activities selected are only a sample of those suggested by NOC and NIC and should be furtherindividualized for each client.

APPLYING CRITICAL THINKING

1. What action would you take if Mrs. Chapman’s heart becameirregular?

2. Mrs. Chapman is responding inappropriately to your questions;she seems to be confused. What do you think is happening?

3. Offer suggestions for ways to help Mrs. Chapman increase heroral intake.

4. Mrs. Chapman asks why you weigh her every morning. How doyou respond?

See Critical Thinking Possibilities in Appendix A.

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nursing intervention nursing intervention nursing intervention

Deficient Fluid Volume r/t nausea, vomiting, diarrhea aeb decreased urine output, increased urineconcentration, weakness, fever, decreased skin turgor, dry mucous membranes, increased pulse,and decreased BP

MC27 y.o. female

assess

generate nursing diagnosis

• Sales clerk, Reports weakness,malaise, and flu-like symptoms for 3-4days. Although thirsty, is unable totolerate fluids because of nausea andvomiting, and she has liquid stools 2-4times per day.

• Height: 160 cm (5' 3")• Weight: 66.2 kg (146 lbs)• T: 38.6°C; P: 96 BPM; • R: 24; BP: 102/84• Dry mucous membranes• Decreased skin turgor

• Urine specific gravity: 1.035• Serum sodium: 155 mEq/L• Serum potassium 3.2 mEq/L• Chest x-ray negative

Outcomes met:• Serum potassium: 3.8 mEq/L• Serum sodium: 140 mEq/L

outcome

outcome

evaluation

evaluationElectrolyte and Acid/Base Balance aebnot compromised• Serum electrolytes• Muscle strength

Outcomes met:• BP: 122/74• P: 74• Urine output increased• Specific gravity: 1.105• Moist mucous membranes• Elastic skin turgor

Fluid balance aeb notcompromised• 24 hour intake and output• Blood pressure, pulse, and temperature• Skin turgor• Urine specific gravity• Mucous membranes

Obtain specimensfor analysis of altered potassiumlevels as indicated

Administer prescribedsupplementalpotassium (PO, NG, or IV) per policy

Monitor forneurologic andneuromuscularmanifestations ofhypernatremia(e.g., lethargy,irritability,seizures,andhyperreflexia)

Providefrequentoralhygiene

Weigh daily and monitortrends

Give fluids as appropriate

Monitorvitals signsas appropriate

Maintainaccurateintake andoutputrecord

Administer IVtherapy asprescribed

Obtain specimens for analysis of altered sodium levels (e.g., serum and urine sodium, urine osmolality, and urine specific gravity) as indicated

Monitor forcardiacmanifestations ofhpyernatremia(e.g., tachycardia,orthostatichypotension)

Monitor forneurologic andneuromuscularmanifestationsof hypokalemia(e.g., hypotension,tachycardia,weak pulse, rhythmirregularities)

activity

activity

activity

activity

activity

activity

activity

activity

activity

activity

activityactivity

Fluid Management Behavior ModificationElectrolyte Management: Hypernatremia

CONCEPT MAP Deficient Fluid Volume

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CHAPTER 52 REVIEW

CHAPTER HIGHLIGHTS■ A balance of fluids, electrolytes, acids, and bases in the body is

necessary for health and life.■ The body fluid is divided into two major compartments: the

intracellular fluid (ICF) inside the cells and extracellular fluid (ECF)outside the cells.

■ Extracellular fluid is subdivided into two compartments:intravascular (plasma) and interstitial. It constitutes about one-fourth to one-third of total body fluid.

■ ECF is in constant motion throughout the body. It is the transportsystem that carries nutrients to and waste products from the cells.

■ The percentage of total body fluids varies according to theindividual’s age, body fat, and sex. The younger the person, thehigher the proportion of water in the body. The less body fatpresent, the greater the proportion of body fluid. Postadolescentfemales have a smaller percentage of fluid in relation to total bodyweight than do men.

■ There are two types of body electrolytes (ions): positively chargedions (cations) and negatively charged ions (anions).

■ The principal ions of ECF are sodium and chloride; the principalions of ICF are potassium and phosphate.

■ Fluids and electrolytes move among the body compartments byosmosis, diffusion, filtration, and active transport.

■ The major fluid pressures exerted as part of the movement of fluidand electrolytes from one compartment to another are osmoticpressure and hydrostatic pressure.

■ The three sources of body fluid are fluids taken orally, foodingested, and the oxidation of food. Fluid intake is regulated by thethirst mechanism.

■ Fluid output occurs chiefly through excretion of urine, although bodyfluid is also lost through sweat, feces, and insensible vapor loss.

■ In healthy adults, measurable fluid intake and output shouldbalance (about 1,500 mL per day). The output of urine normallyapproximates the oral intake of fluids. Water from food andoxidation is balanced by fluid loss through the skin, respiratoryprocess, and feces.

■ A number of body systems and organs are involved in regulatingthe volume and composition of body fluids: the kidneys, theendocrine system, the cardiovascular system, the lungs, and thegastrointestinal system. The kidneys are the primary regulator offluid and electrolyte balance.

■ Substances such as the antidiuretic hormone, the renin-angiotensin-aldosterone system, and the atrial natriuretic factor arealso involved in maintaining fluid balance.

■ Fluid imbalances includea. Fluid volume deficit (FVD), also referred to as hypovolemia.b. Fluid volume excess (FVE), also referred to as hypervolemia.c. Dehydration, a deficit in water and increase in serum

sodium level.d. Overhydration, an excess of water and decrease in serum

sodium level.■ The most common electrolyte imbalances are deficits or excesses

in sodium, potassium, and calcium.■ The acid–base balance (pH range) of body fluids is maintained

within a precise range of 7.35 to 7.45.

■ Acid–base balanceis regulated bybuffers that neutralizeexcess acids or bases; thelungs, which eliminate or retain carbon dioxide, a potential acid;and the kidneys, which excrete or conserve bicarbonate andhydrogen ions.

■ Acid–base imbalance occurs when the normal 20-to-1 ratio ofbicarbonate to carbonic acid is upset. Imbalances may be eitherrespiratory or metabolic in origin; either can result in acidosis oralkalosis.

■ Factors that influence an individual’s fluid, electrolyte, andacid–base balance include age, gender and body size,environmental temperature, and lifestyle. Illness, trauma, surgery,and certain medications can place individuals at risk for fluid,electrolyte, and acid–base imbalances.

■ Fluid, electrolyte, and acid–base imbalance is most accuratelydetermined through laboratory examination of blood plasma.

■ Assessment relative to fluid, electrolyte, and acid–base balancesincludes (a) a nursing history; (b) physical examination of theskin, oral cavity, eyes, jugular vein, veins of the hand, and theneurologic system; (c) measurement of body weight, vital signs,and fluid intake and output; and (d) various diagnostic studies ofblood and urine.

■ A nursing history includes data about the client’s fluid and foodintake; fluid output; signs of fluid, electrolyte, and acid–baseimbalances; and medications, therapies, or disease processes thatmay disrupt these balances.

■ NANDA-approved nursing diagnoses that relate specifically to fluid,electrolyte, and acid–base imbalances include Deficient FluidVolume, Excess Fluid Volume, Risk for Imbalanced Fluid Volume,Risk for Deficient Fluid Volume, and Impaired Gas Exchange. Otherdiagnoses that may be relevant are Impaired Oral MucousMembrane, Impaired Skin Integrity, Decreased Cardiac Output,Impaired Tissue Perfusion, Activity Intolerance, Risk for Injury, andAcute Confusion.

■ In many instances, fluids and electrolytes can be provided orally toclients who are experiencing or at risk of developing fluid deficits.The nurse needs to establish with the client a 24-hour plan foringesting the necessary fluids and to respect the client’s fluidpreferences.

■ For clients with fluid retention, fluids may need to be restricted; aschedule and short-term goals that make the fluid restriction moretolerable need to be developed.

■ For clients experiencing excessive fluid losses, the administration offluids and electrolytes intravenously is necessary. Meticulousaseptic technique is required when caring for clients withintravenous infusions.

■ Preventing complications such as infiltration, phlebitis,hypervolemia (circulatory overload), and infection is an importantaspect of intravenous therapy.

■ The administration of blood transfusions involves accuratelymatching and identifying the blood for the individual, correctlyidentifying the recipient, and monitoring the client throughout theprocedure for transfusion reactions.

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TEST YOUR KNOWLEDGE1. An elderly nursing home resident has refused to eat or drink for

several days and is admitted to the hospital. The nurse shouldassess for which of the following?1. Increased blood pressure2. Weak, rapid pulse3. Moist mucous membranes4. Jugular vein distention

2. A man brings his elderly wife to the emergency department. Hestates that she has been vomiting and has had diarrhea for thepast 2 days. She appears lethargic and is complaining of legcramps. What should the nurse do first?1. Start an IV.2. Review the results of serum electrolytes.3. Offer the woman foods that are high in sodium and

potassium content.4. Administer an antiemetic.

3. The nurse administers an IV solution of D5 1⁄2 NS to apostoperative client. This is classified as what type ofintravenous solution? ___________

4. An older client comes to the emergency departmentexperiencing chest pain and shortness of breath. An arterialblood gas is ordered. Which of the following ABG resultsindicates respiratory acidosis?1. pH 7.54; PaCO2 28 mm Hg; HCO3 22 mEq/L2. pH 7.32; PaCO2 46 mm Hg; HCO3 24 mEq/L3. pH 7.31; PaCO2 35 mm Hg; HCO3 20 mEq/L4. pH 7.50; PaCO2 37 mm Hg; HCO3 28 mEq/L

5. The intake and output (I & O) record of a client with anasogastric tube that has been attached to suction for two (2)days shows greater output than input. Which nursing diagnosesare most applicable? Select all that apply.1. Deficient Fluid Volume2. Risk for Deficient Fluid Volume3. Impaired Oral Mucous Membranes4. Impaired Gas Exchange5. Decreased Cardiac Output

6. Which of the following client statements indicates a need forfurther teaching regarding treatment for hypokalemia?1. “I will use avocado in my salads.”2. “I will be sure to check my heart rate before I take my

digoxin.”3. “I will take my potassium in the morning after eating

breakfast.”4. “I will stop using my salt substitute.”

7. An elderly man is admitted to the medical unit with a diagnosisof dehydration. Which of the following signs or symptoms aremost representative of a sodium imbalance?1. Hyperreflexia2. Mental confusion3. Irregular pulse4. Muscle weakness

8. The client’s arterial blood gas results are: pH 7.32; PaCO2 58;HCO3 32. The nurse knows that the client is experiencing whichacid–base imbalance?1. Metabolic acidosis2. Respiratory acidosis3. Metabolic alkalosis4. Respiratory alkalosis

9. A client is admitted to the hospital for hypocalcemia. Nursinginterventions relating to which system would have the highestpriority?1. Renal2. Cardiac3. Gastrointestinal4. Neuromuscular

10. The nurse would assess for signs of hypomagnesemia in whichof the following clients? Select all that apply.1. A client with renal failure2. A client with pancreatitis3. A client taking magnesium-containing antacids4. A client with excessive nasogastric drainage5. A client with chronic alcoholism

See Answers to Test Your Knowledge in Appendix A.

EXPLORE MEDIALINK www.prenhall.com/bermanDVD-ROM■ Audio Glossary■ NCLEX Review■ Skills Checklists■ Animations:

Membrane TransportFiltration PressureFluid BalanceAcid–Base BalanceFurosemide DrugApplying a Central Venous Line

COMPANION WEBSITE■ Additional NCLEX Review■ Case Study: Client with Suspected Electrolyte Imbalance■ Care Plan Activity: Client with Heart Failure■ Application Activities:

Determining Body Fluid ProblemsArterial Blood Gases and Acid–Base Balance

■ Links to Resources

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CHAPTER 52 / Fluid, Electrolyte, and Acid-Base Balance 1483

READINGS AND REFERENCESSUGGESTED READINGSBillings, D., & Kowalski, K. (2005). Do your CATS

PRRR? A mnemonic device to teach safetychecks for administering intravenousmedications. Journal of Continuing Educationin Nursing, 36(3), 104–106.The authors suggest using this mnemonic(CATS PRRR) to help nurses remember theimportant safety checks of IV medicationadministration. Having this mnemonic writtenon the nurse’s clipboard will help the nurse tostay focused on the task in a hectic andstressful working environment. The articleexplains how each letter pertains to importantsafety checks when administering IVmedications.

Davidhizar, R., Dunn, C. L., & Hart, A. N. (2004). Areview of the literature on how importantwater is to the world’s elderly population.International Nursing Review, 51(3), 159–167.These authors discuss the importance ofwater to the elderly population and providestrategies to promote health related to waterintake.

Mentes, J. (2006). Oral hydration in older adults.American Journal of Nursing, 106(6), 40–49.This article reviews age-related changes, riskfactors, assessment measures, and nursinginterventions for dehydration.

Rosenthal, K. (2003). Keeping I.V. therapy safe withneedleless systems. Nursing, 33(10), 16–20.This article details how needleless systemsreduce the health care professional’s risk ofinjury and exposure to bloodborne pathogens.

Rosenthal, K. (2004). The new look of I.V.therapy: Improvements to existing productsand technology enhance patient care,satisfaction, and outcomes. NursingManagement, 35(12), 66–70.This article provides information about thenew infusion devices that are now available.This author provides information on an arrayof anesthetics and needleless IV devices.

RELATED RESEARCHBerk, D. R., Conti, P. M., & Sommer, B. R.

(2004/2005). Orange juice-inducedhyperkalemia in schizophrenia. InternationalJournal of Psychiatry in Medicine, 34(1), 79–82.

Crawford, A. (2004). An audit of the patient’sexperience of arterial blood gas testing. BritishJournal of Nursing, 13(9), 529–532.

Da Silva, L. (2004). The use & abuse of parenteralnutrition: Can we change practice? CanadianJournal of Dietetic Practice and Research, 26, 3.

Mentes, J. C. (2006). A typology of oral hydration:Problems exhibited by frail nursing homeresidents. Journal of Gerontological Nursing,32(1), 13–19.

Oh, H., Suh, Y., Hwang, S., & Seo, W. (2005).Effects of nasogastric tube feeding on serumsodium, potassium, and glucose levels. Journalof Nursing Scholarship, 37(2), 141–147.

Wathen, J. E., MacKenzie, T., & Bothner, J. P.(2004). Usefulness of the serum electrolytepanel in the management of pediatricdehydration treated with intravenouslyadministered fluids. Pediatrics, 114(5),1227–1234.

REFERENCESAmerican Medical Association, American Nurses

Association–American Nurses Foundations,Centers for Disease Control and Prevention,Center for Food Safety and Applied Nutrition,Food and Drug Administration, Food Safety

and Inspection Service, U.S. Department ofAgriculture. (2004). Diagnosis andmanagement of foodborne illnesses: A primerfor physicians and other health careprofessionals. Morbidity and Mortality WeeklyReport, 53 (RR-4), 1–33.

Andrews, M. M., & Boyle, J. S. (2003).Transcultural concepts in nursing care (4thed.). Philadelphia: Lippincott Williams &Wilkins.

Astle, S. M. (2005). Restoring electrolyte balance.RN, 68(5), 34–39.

Bennett, J. A., Thomas, V., & Riegel, B. (2004).Unrecognized chronic dehydration in olderadults. Examining prevalence rate and riskfactors. Journal of Gerontological Nursing,30(1), 22–28.

Dochterman, J. M., & Bulechek, G. M. (Eds.).(2004). Nursing interventions classification(NIC) (4th ed.). St. Louis, MO: Mosby.

Elgart, H. N. (2004). Assessment of fluids andelectrolytes. AACN Clinical Issues, 15(4),607–621.

Food and Drug Administration (FDA). (2004). Barcode label requirements for human drugproducts and biological products. FederalRegister, 69(38), 9119–9171.

Hadaway, L. C. (2004). Preventing and managingperipheral extravasation. Nursing, 34(5), 66–67.

Hayes, D. D. (2004). Calcium in the balance.Nursing Made Incredibly Easy, 2(2), 46–53.

Masoorli, S., & Angeles, T. (2002). Getting a lineon central vascular access devices. Nursing,32(4), 36–43.

Moorhead, S., Johnson, M., & Maas, M. (Eds.).(2004). Nursing outcomes classification(NOC) (3rd ed.). St. Louis, MO: Mosby.

NANDA International. (2007). NANDA nursingdiagnoses: Definitions and classification2007–2008. Philadelphia: Author.

Phillips, L. D. (2005). Manual of I.V. therapeutics(4th ed.). Philadelphia: F. A. Davis.

Rosenthal, K. (2004). Avoiding bad blood: Keysteps to safe transfusions. Nursing MadeIncredibly Easy, 2(5), 20–29.

Rosenthal, K. (2005a). Tailor your I.V. insertiontechniques for special populations. Nursing,35(5), 37–41.

Rosenthal, K. (2005b). Ports: The gateway tocentral lines. Nursing Made Incredibly Easy,3(1), 53–56.

Simpson, H. (2004). Interpretation of arterialblood gases: A clinical guide for nurses. BritishJournal of Nursing, 13(9), 522–528.

Spandorfer, P. R., Alessandrini, E. A., Joffe, M. D.,Localio, R., & Shaw, K. N. (2005). Oral versusintravenous rehydration of moderatelydehydrated children: A randomized, controlledtrial. Pediatrics, 115(2), 295–301.

Wilburn, S. Q. (2004). Needlestick and sharpsinjury prevention. Online Journal of Issues inNursing, 9(3), manuscript 4. Retrieved July 15,2006, from http://www.nursingworld.org/ojin/topic25/tpc25_4.htm

Yucha, C. (2004). Renal regulation of acid–basebalance. Nephrology Nursing Journal, 31(2),201–208.

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