Post on 26-Mar-2015
1Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Chapter 14
Fluids and Electrolytes
2Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Learning Objectives
• Describe the extracellular and intracellular fluid compartments.• Describe the composition of the extracellular and intracellular body
fluid compartments.• Discuss the mechanisms of fluid transport and fluid balance.• Identify the causes, signs and symptoms, and treatment of fluid
imbalances.• Describe the major functions of all of the major electrolytes—
sodium, potassium, calcium, magnesium, and chloride.• Identify the causes, signs and symptoms, and treatment of
electrolyte imbalances.
3Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Learning Objectives
• List data to be collected in assessing fluid and electrolyte status.• Discuss the medical treatment and nursing management of persons
with fluid and electrolyte imbalances.• Explain why older persons are at increased risk for fluid and
electrolyte imbalances.• List the four types of acid-base imbalances.• Identify the major causes of each acid-base imbalance.• Explain the management of acid-base imbalances.
4Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Homeostasis
• Maintaining relatively constant conditions as in fluid compartments
• To maintain internal balance, body must be able to regulate fluids
• All organs and structures of the body involved in homeostasis
5Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Homeostasis
• Intracellular fluid• Fluid within a cell• Most of body’s fluids found within the cell
• Extracellular fluid • Fluid outside the cell• Intravascular fluid
• In blood vessels in the form of plasma or serum
• Interstitial fluid• In fluid surrounding cells, including lymph
6Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Water
• Largest portion of body weight• Percentage affected by age, sex, body fat
• Percentage of body water decreases with age• Females have a lower percentage of body water
than males throughout adult years because women have more fat than men and fat cells contain less water than other cells
• Obese have a lower percentage of body water because of the increased number of fat cells
7Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Solutes
• Electrolyte• Substance that develops an electrical charge when
dissolved in water • Examples: sodium, potassium, calcium, chloride,
bicarbonate, and magnesium• Maintain balance between positive and negative
charges • For every positively charged cation, there is a
negatively charged anion • Cations and anions combine to balance one another
8Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Solutes
• Sodium (Na) • Most abundant electrolyte; primary electrolyte in
extracellular fluid • Major role in regulating body fluid volumes,
muscular activity, nerve impulse conduction, and acid-base balance
9Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Solutes
• Potassium (K) • Found mainly in the intracellular fluid; the major
intracellular cation• Important in maintaining fluid osmolarity and volume
within the cell• Essential for normal membrane excitability—a
critical factor in transmitting nerve impulses • Needed for protein synthesis, for the synthesis and
breakdown of glycogen, and to maintain plasma acid-base balance
10Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Solutes
• Chloride (Cl) • An extracellular anion that is usually bound with
other ions, especially sodium or potassium • Functions are to regulate osmotic pressure between
fluid compartments and assist in regulating acid-base balance
11Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Solutes
• Calcium (Ca)• Usually combined with phosphorus to form the
mineral salts of the bones and teeth • Of total body calcium, 99% concentrated in the bones and
teeth; 1% is in the extracellular fluid
• Ingested through the diet and absorbed through the intestine
• Promotes transmission of nerve impulses; helps regulate muscle contraction and relaxation
12Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Solutes
• Magnesium (Mg2+) • A cation found in bone (50% to 60%), intracellular
fluid (39% to 49%), and extracellular fluid (1%) • Plays a role in the metabolism of carbohydrates and
proteins, the storage and use of intracellular energy, and neural transmission
• Important in heart, nerve, and muscle function
13Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Solutes
• Nonelectrolytes• Other substances dissolved in the body fluids
• Urea, protein, glucose, creatinine, and bilirubin • These solutes do not carry an electrical charge
14Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Transport of Water and Electrolytes
• Membranes• Selectively permeable membranes
• Separate fluid compartments and control movement of water and certain solutes
• Maintain unique composition of each compartment of the body while allowing transport of nutrients and wastes to and from cells
• Some solutes cross membranes more easily than others
15Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Transport Processes
• Diffusion• The random movement of particles in all directions
is for a substance to move from an area of higher Natural tendency concentration to an area of lower concentration
• Facilitated diffusion • A carrier protein transports the molecules through
membranes toward an area of lower concentration
16Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Transport Processes
• Active transport• Carrier proteins transport substances from an area
of lower concentration to an area of equal or greater concentration
• Requires expenditure of energy• Many solutes, such as sodium, potassium, glucose,
and hydrogen, are actively transported across cell membranes
17Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Transport Processes
• Filtration• Transfer of water and solutes through a membrane
from an area of high pressure to an area of low pressure
• Hydraulic pressure• A combination of pressures from the force of gravity on the
fluid and the pumping action of the heart
• Needed to move fluid out of capillaries into tissues and filter plasma through the kidneys
18Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Transport Processes
• Osmosis• Movement across a membrane from a less
concentrated to a more concentrated solution• Involves movement of water only; sometimes force
of movement across membrane carries solutes along
• If a fluid compartment has less water and more sodium, water from another compartment moves to the more concentrated compartment by osmosis to create a better fluid balance
19Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Osmolality
• Concentration of solution determined by number of dissolved particles per kg water
• Controls water movement and distribution by regulating the concentration of fluid in each body fluid compartment
• The osmolality of intracellular fluid and extracellular fluid tends to equalize because of the constant shifting of water
20Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Regulatory Mechanisms
21Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Kidneys
• Main regulators of fluid balance • Control extracellular fluid by adjusting the
concentration of specific electrolytes, osmolality of body fluids, the volume of extracellular fluid, blood volume, and pH
• The nephron is the functioning unit of the kidney • Glomerulus is the filtering portion of the nephron, and
the tubule is responsible for secretion and reabsorption • Nephrons conduct work of the kidney through filtration,
reabsorption, and secretion
22Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Kidneys
• Filtration• Blood plasma entering the kidney via the renal
artery is delivered to the glomerulus • About 20% of plasma filtered into glomerular
capsule • Most remaining plasma leaves kidney through the
renal vein • Filtrate then moves through the tubules, where it is
transformed into urine by tubular reabsorption and secretion
23Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Kidneys
• Tubular reabsorption• A process by which most of the glomerular filtrate is
returned to the circulation • Water and selected solutes move from the tubules
into the capillaries • Waste products remain in tubules for excretion,
whereas most water and sodium is reabsorbed into the bloodstream
• Adjusts volume and composition of the filtrate; prevents excessive fluid loss through kidneys
24Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Kidneys
• Tubular secretion• The last phase in the work of the kidneys • The filtrate is transformed into urine • Various substances—drugs, hydrogen ions,
potassium ions, creatinine, and histamine—pass from the blood into the tubules
• Process eliminates some excess substances to maintain fluid and electrolyte balance, as well as metabolic waste products
25Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hormones
• Renin • Hormone secreted when blood volume or blood
pressure falls• Causes the release of aldosterone with subsequent
sodium and water retention• Aldosterone• Acts on kidney tubules to increase reabsorption of
sodium and decrease reabsorption of potassium • Because the retention of sodium causes water
retention, aldosterone acts as a volume regulator
26Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hormones
• Antidiuretic hormone (ADH) • Causes capillaries to reabsorb more water, so urine
is more concentrated and less volume is excreted
• Atrial natriuretic factor (ANF)• Hormone released by the atria in response to
stretching of the atria by increased blood volume • Stimulates excretion of sodium and water by the
kidneys, decreased synthesis of renin, decreased release of aldosterone, and vasodilation
• Reduces blood volume and lowers blood pressure
27Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Thirst
• Regulates fluid intake• Increased plasma osmolality stimulates
osmoreceptors in the hypothalamus to trigger the sensation of thirst
• More sodium and less water in the body make a person thirsty
• Additional fluids consumed; kidneys conserve water until osmolality returns to normal
28Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.Figure 14-1
29Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Fluid Gains and Losses
• In healthy adult, 24-hour fluid I&O approximately equal
• Fluids gained by drinking and eating and lost through the kidneys, skin, lungs, and gastrointestinal tract
• The usual adult urine volume is between 1 and 2 L/day, or 1 ml/kg of body weight per hour
• In kidneys, water loss varies largely with the amount of solute excreted and with the level of antidiuretic hormone
30Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Fluid Gains and Losses
• Losses through the skin occur by sweating • Water loss through the lungs by evaporation at
300 to 400 ml/day • In the gastrointestinal tract, the usual loss of
fluid is about 100 to 200 ml/day
31Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Age-Related Changes Affecting Fluid Balance
• Aging kidney slower to adjust to changes in acid-base, fluid, and electrolyte balances
• Older adult often has a reduced sense of thirst and therefore may be in a state of chronic dehydration
• Total body water declines with age; greatest loss from the intracellular fluid compartment
32Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Age-Related Changes Affecting Fluid Balance
• Older person has limited reserves to maintain fluid balance when abnormal losses occur
• Antihypertensives, diuretics, and antacids can also contribute to imbalances
• Unless contraindicated, fluid requirements for older adults, based on ideal body weight, are
30 ml/kg for ages 55 to 65 and 25 ml/kg 65 years and older
33Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Assessment of Fluid and Electrolyte Balance
• Health history• Determines if patient has conditions that contribute
to fluid or electrolyte imbalances• Vomiting, diarrhea, kidney diseases, diabetes, salicylate
poisoning, burns, congestive heart failure, cerebral injuries, ulcerative colitis, and hormonal imbalances; the intake of drugs, such as diuretics and cathartics; and medical interventions, such as gastric suctioning
• Complaints of fatigue, palpitations, dizziness, edema, muscle weakness or cramps, dyspnea, and confusion may be associated with fluid imbalances
34Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Assessment of Fluid and Electrolyte Balance
• Vital signs• Pulse, respiration, temperature, and blood pressure
can indicate changes in fluid and electrolyte balance.
• Temperature variations can be associated with fluid volume excess or deficit.
• Pulse rate and quality may change in response to blood volume alterations; electrolyte changes can affect heart rate and rhythm. Blood pressure is directly related to blood volume. Respirations are minimally affected by electrolyte changes.
35Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Assessment of Fluid and Electrolyte Balance
• Intake and output• Accurate records are essential to determine whether
the patient’s intake is equal to output • All fluids entering or leaving the body should be
noted• A changing urine output may reflect attempts by the
kidneys to maintain or restore balance, or it may reflect a problem that causes fluid disturbances
• Urine characteristics also give clues to fluid balance
• Clear, pale urine in a healthy person suggests the excretion of excess water, whereas darker, concentrated urine indicates the kidneys are retaining water
36Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Assessment of Fluid and Electrolyte Balance
• Skin• Characteristics
• Moisture, turgor, and temperature reflect fluid balance. Dry, flushed skin—dehydration. Pale, cool, clammy skin—severe fluid volume deficit that occurs with shock. Moist, edematous tissue seen with excess fluid volume
• Facial characteristics• Severely dehydrated patient has a pinched, drawn facial
expression. Soft eyeballs and sunken eyes indicate severely deficient fluid volume. Puffy eyelids and fuller cheeks suggest excess fluid volume
37Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Assessment of Fluid and Electrolyte Balance
• Skin turgor• Measured by pinching the skin over the sternum,
the inner aspects of the thighs, or the forehead • In patients who are dehydrated, skin flattens more
slowly after the pinch is released
• Edema• Reflects water and sodium retention, which can
result from excessive reabsorption or inadequate secretion of sodium, as may occur with kidney failure
• Pitting depression remains in the tissue after pressure is applied with a fingertip
38Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Assessment of Fluid and Electrolyte Balance
• Mucous membranes• Tongue turgor
• In well person, tongue has one longitudinal furrow. Fluid volume deficit causes additional longitudinal furrows, and the tongue is smaller. Sodium excess causes the tongue to appear red and swollen.
• Moisture of the oral cavity• A dry mouth may be the result of deficient fluid volume or
mouth breathing.
• Veins• Appearance of the jugular veins in the neck and the veins
in the hands can suggest either a fluid volume deficit or excess.
39Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Diagnostic Tests and Procedures
• Urine studies• Urine pH
• Determines if kidneys are responding appropriately to metabolic acid-base imbalances
• Urine specific gravity• A measure of urine concentration• A good indicator of fluid balance
• Osmolality
• Measures the number of dissolved particles in a solution • Provides more precise measurement of kidney’s ability to
concentrate urine
40Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Diagnostic Tests and Procedures
• Urine creatinine clearance tests• Detect glomerular damage in the kidney • A 24-hour specimen is required
• Urine sodium • Sodium intake and fluid volume status
• Urine potassium • A measure of renal tubular function
41Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Diagnostic Tests and Procedures
• Blood studies• Serum hematocrit
• Percentage of blood volume composed of red blood cells
• Serum creatinine• A metabolic waste product • Indicator of renal function
• Blood urea nitrogen (BUN) • A measure of renal function
42Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Diagnostic Tests and Procedures
• Serum albumin• A plasma protein that helps maintain blood volume
by creating colloid osmotic pressure
• Serum electrolytes• Sodium, potassium, chloride, and calcium
43Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Fluid Imbalances
• Deficient fluid volume• Less water than normal in the body • Isotonic extracellular fluid deficit
• Hypovolemia
• Hypertonic extracellular fluid deficit • Dehydration
• Decreased intake, abnormal fluid losses, or both
• Examples: loss of water from excessive bleeding, severe vomiting/diarrhea, severe burns
44Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Fluid Imbalances
• Excess fluid volume • An increase in body water
• Extracellular fluid excess• Isotonic fluid excess
• Intracellular water excess • Hypotonic fluid excess
• From renal or cardiac failure with retention of fluid, increased production of antidiuretic hormone or aldosterone, overload with isotonic IV fluids, or administration of dextrose 5% in water (D5W) after surgery or trauma
45Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Electrolyte Imbalances
46Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hyponatremia
• Lower than normal sodium in the blood serum • Can be actual deficiency of sodium or increase
in body water that dilutes the sodium excessively
• Assessment• Symptoms: headache, muscle weakness, fatigue,
apathy, confusion, abdominal cramps, and orthostatic hypotension
• Take blood pressures with the patient lying or sitting and then standing to determine if a significant drop
47Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hyponatremia
• Medical treatment• The usual treatment is restriction of fluids while the
kidneys excrete excess water • Diuretic: furosemide (Lasix) • Sodium replacement therapy
• Nursing care• Administer prescribed medications and IV fluids• Measure fluid intake and output and assess mental
status
48Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hypernatremia
• Higher than normal concentration of sodium in the blood• Very serious imbalance; can lead to death if not
corrected• Occurs when excessive loss of water or excessive
retention of sodium• Signs and symptoms
• Thirst, flushed skin, dry mucous membranes, low urine output, restlessness, increased heart rate, convulsions, and postural hypotension
49Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hypernatremia
• Medical treatment• Oral or IV replacement of water to restore balance• A low-sodium diet often prescribed
• Nursing care• Encourage patients with hypernatremia to drink
water• Closely monitor the infusion of IV fluids• Teach patient to track daily I&O and to recognize
the signs and symptoms of fluid retention or depletion
50Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hypokalemia
• Low serum potassium• May result in gastrointestinal, renal, cardiovascular,
and neurologic disturbances• Can cause abnormal, potentially fatal, heart rhythm• Signs and symptoms
• Anorexia, abdominal distention, vomiting, diarrhea, muscle cramps, weakness, dysrhythmias (abnormal cardiac rhythms), postural hypotension, dyspnea, shallow respirations, confusion, depression, polyuria (excessive urination), and nocturia
51Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hypokalemia
• Medical treatment• Potassium replacement by the IV or oral route
• Nursing care• Monitoring at-risk patients for decreased bowel
sounds, a weak and irregular pulse, decreased reflexes, and decreased muscle tone
• Cardiac monitors may be used to detect dysrhythmias
• Administer oral or IV potassium• Urine output should be no less than 30 ml/hr
52Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hyperkalemia
• High serum potassium• Patients at risk: decreased renal function, in
metabolic acidosis, taking potassium supplements • A serious imbalance because of the potential for
life-threatening dysrhythmias• Signs and symptoms
• Explosive diarrhea and vomiting; muscle cramps and weakness, paresthesia, irritability, anxiety, abdominal cramps, and decreased urine output
53Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Hyperkalemia
• Medical treatment • Correct the underlying cause• Restrict potassium intake • Polystyrene sulfonate (Kayexalate)• Intravenous calcium gluconate
• Nursing care• Patients with low urine output or those taking
potassium-sparing diuretics must be monitored carefully for signs and symptoms
• Carefully monitor flow rate of IV fluids, which should not exceed 10 mEq/hr through peripheral veins
• Screen the results of laboratory studies
54Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Chloride Imbalance
• Usually bound to other electrolytes; therefore, chloride imbalances accompany other electrolyte imbalances• Hyperchloremia
• Usually associated with metabolic acidosis
• Hypochloremia• Usually occurs when sodium is lost because chloride most
frequently bound with sodium
55Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Calcium Imbalance
• Regulated by the parathyroid glands• Hypocalcemia results from diarrhea, inadequate dietary
intake of calcium or vitamin D, and multiple blood transfusions (banked blood contains citrates that bind to calcium), in addition to some diseases, including hypoparathyroidism
• Hypercalcemia results from a high calcium or vitamin D intake, hyperparathyroidism, and immobility that causes stores of calcium in the bones to enter the bloodstream
56Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Magnesium Imbalance
• Hypomagnesemia: decreased gastrointestinal absorption or excessive gastrointestinal loss, usually from vomiting and diarrhea, or increased urinary loss
• Hypermagnesemia occurs most often with excessive use of magnesium-containing medications or intravenous solutions in patients with renal failure or preeclampsia of pregnancy
57Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Acid-Base Disturbances
58Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Respiratory Acidosis
• Respiratory system fails to eliminate the appropriate amount of carbon dioxide to maintain the normal acid-base balance
• Caused by pneumonia, drug overdose, head injury, chest wall injury, obesity, asphyxiation, drowning, or acute respiratory failure
• Medical treatment• Improve ventilation, which restores partial pressure
of carbon dioxide in arterial blood (Paco2) to normal
59Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Respiratory Acidosis
• Nursing care• Assess Paco2 levels in the arterial blood
• Observe for signs of respiratory distress: restlessness, anxiety, confusion, tachycardia
• Intervention• Encourage fluid intake • Position patients with head elevated 30 degrees
60Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Respiratory Alkalosis
• Low Paco2 with a resultant rise in pH• Most common cause of respiratory alkalosis is
hyperventilation • Medical treatment
• Major goal of therapy: treat underlying cause of condition; sedation may be ordered for the anxious patient
61Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Respiratory Alkalosis
• Nursing care• Intervention
• In addition to giving sedatives as ordered, reassure the patient to relieve anxiety
• Encourage patient to breathe slowly, which will retain carbon dioxide in the body
62Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Metabolic Acidosis
• Body retains too many hydrogen ions or loses too many bicarbonate ions; with too much acid and too little base, blood pH falls
• Causes are starvation, dehydration, diarrhea, shock, renal failure, and diabetic ketoacidosis
• Signs and symptoms: changing levels of consciousness, headache, vomiting and diarrhea, anorexia, muscle weakness, cardiac dysrhythmias
• Medical treatment: treat the underlying disorder
63Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Metabolic Acidosis
• Nursing care• Assessment of the patient in metabolic acidosis
should focus on vital signs, mental status, and neurologic status
• Emergency measures to restore acid-base balance. Administer drugs and intravenous fluids as prescribed. Reassure and orient confused patients
64Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Metabolic Alkalosis
• Increase in bicarbonate levels or a loss of hydrogen ions
• Loss of hydrogen ions may be from prolonged nasogastric suctioning, excessive vomiting, diuretics, and electrolyte disturbances
• Signs and symptoms: headache; irritability; lethargy; changes in level of consciousness; confusion; changes in heart rate; slow, shallow respirations with periods of apnea; nausea and vomiting; hyperactive reflexes; and numbness of the extremities
65Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Metabolic Alkalosis
• Medical treatment• Depends on the underlying cause and severity of
the condition
66Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Metabolic Alkalosis
• Nursing care • Assessment
• Take vital signs and daily weight; monitor heart rate, respirations, and fluid gains and losses
• Keep accurate intake and output records, including the amount of fluid removed by suction
• Assess motor function and sensation in the extremities; monitor laboratory values, especially pH and serum bicarbonate levels
67Elsevier items and derived items © 2007 by Saunders, an imprint of Elsevier, Inc.
Metabolic Alkalosis
• Intervention• To prevent metabolic alkalosis, use isotonic saline
solutions rather than water for irrigating nasogastric tubes because the use of water for irrigation can result in a loss of electrolytes
• Provide reassurance and comfort measures to promote safety and well-being