Generic Case Review

Robert Zaid2/24/06

Chief Complaint

• 59 year old caucasion female brought in after falling down 13 stairs that morning

• Consultation for medical management was ordered for our service

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

History of Present Illness Pt is a 59 y/o c female who was found at bottom of stairs by her husband who noticed that she was having trouble breathing. Pt is unresponsive and unable to provide history and her husband does not know her history as well. This was her first admission to the hospital. She has consumed alcohol in the past day.

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

Past Medical History

Unable to obtain

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Medications

Unable to obtain

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Allergies

Unable to obtain

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Social History

She is a smoker and drinks alchohol

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

Family Medical History

Unable to obtain

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

Review of systems

General: weight change, fever, chills, weakHead: headache, nasuea, vomittingRespiratory: SOB, wheeze, coughCardiac: HTN, murmurs, angina, palpitationsGI: appetite, n/v, incont., const/diarrheaGU: frequency, hesitancy, urgency, dysuria

hematuria, incont., stones, no dyspareunia, no discharge

MSK: muscle weakness, flank painNeuro: parasthesias, loss of sensationPsychiatric- Pt is not depressed

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

Physical ExamVS- BP- 113/65 HR 92 11 R 97General- Pt is well nourished and not alertHeent- EOMI, PERRLA, no vision changesCV- RRR w/o murmurs or rubs, clicks or gallopsRESP- Clear to auscultation bilaterally, no wheezesAbdomen- Soft, NT, ND, no masses, BS, no bruitsGU- No discharge, bleeding, nodules or massesMSK- No weakness, EXT- No edema, negative moses, pulses b/lSkin- No rashesOst-Neuro-

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

Differential

Need to rule out any foul play

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

What do we want to order?

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

Labs

ChemistryCBC

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

CBC

10.413.6

40.5

218

Chemistry

120

3.3

85

22

2

0.6

98

Pregnancy TestNegative

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

• CC• HPI• PMHx• MEDS• Allergies• SocHx• FMHx• ROS• Physical Exam• Differential• LABS• Radiological• Differential• Diagnosis• Treatment

Diagnosis

1. Medical management of hypokalemia withhyponatremia

HyponatremiaBackground

• Maintenance– Homeostatic mechanisms

• Thirst• Antidiuretic hormone (ADH)• Renal handling of filtered sodium

• Clinically significant hyponatremia – Relatively uncommon – Nonspecific in its presentation

• Correction– Irreparable harm

• If corrected too quickly or too slowly

HyponatremiaBackground

• Hypovolemic hyponatremia – Total body water (TBW)

decreases– Total body sodium (Na+)

decreases more– Extracellular fluid (ECF) volume is

decreased. • Euvolemic hyponatremia

– TBW increases – Total sodium remains normal– ECF volume is increased

minimally to moderately– No edema

• Hypervolemic hyponatremia – Total body sodium increase– TBW increases to a greater extent– ECF is increased markedly– Edema is present.

• Redistributive hyponatremia – Water shifts from the intracellular

to the extracellular compartment– Resultant dilution of sodium– TBW and total body sodium are

unchanged– Occurs with hyperglycemia.

• Pseudohyponatremia – Diluted by excessive proteins or

lipids– TBW and total body sodium are

unchanged– Hypertriglyceridemia and multiple

myeloma

HyponatremiaPathophysiology

• Regulation– Thirst– ADH– Renin-angiotensin-aldosterone system– Renal handling of filtered sodium

• Stimulation – Increases in serum osmolarity above the normal range (280-300 mOsm/kg) – Stimulate hypothalamic osmoreceptors– Cause an increase in thirst and in circulating levels of ADH

• Mechanism of ADH– Increases free water reabsorption from urine

• Low urine volumes • Relatively high urine osmolarity • Returning serum osmolarity toward normal• ADH also is secreted in response to:

– Hypovolemia– Pain– Fear– Nausea– Hypoxia

HyponatremiaPathophysiology

• Regulation– Thirst– ADH– Renin-angiotensin-aldosterone system– Renal handling of filtered sodium

• Aldosterone– Synthesized by the adrenal cortex– Regulated primarily by serum potassium– Released in response to hypovolemia

• Renin-angiotensin-aldosterone axis– Effect:

• Causes absorption of sodium – Distal renal tubule

• Sodium retention obligates free water retention• Aides the hypovolemic state.

HyponatremiaPathophysiology

• Disorders of sodium balance – Disturbance

• Thirst• Water acquisition• ADH• Aldosterone• Rrenal sodium transport.

• Significant hyponatremia– State of extracellular hypo-osmolarity– Tendency for free water to shift from the vascular space to the intracellular space– Cellular edema is well tolerated by most tissues

• Not tolerated by calvarium– Cerebral edema.

• Rate– Slowly

• Several days or weeks– Brain is capable of compensating – Extrusion of solutes and fluid to the extracellular space

– Fast• 24-48 hours• Compensatory mechanism is overwhelmed • Severe cerebral edema may ensue• Resulting in brainstem herniation and death.

HyponatremiaHistory

• Symptoms – May be limited

• Mild anorexia• Headache• Muscle cramps

– Severe• Obtundation• Coma• Status epilepticus

• Look for causes in history– Seen with chronic disease

• Pulmonary/mediastinal disease• CNS disorders

– Medications– Poor diet– Intake of large amounts of beer– Ectasy

HyponatremiaHistory

• Hypoosmolor hyponatremia– Hypothyroidism – Adrenal insufficiency

• Clinically significant hyponatremia– Anorexia– Nausea and vomiting– Difficulty concentrating– Confusion– Lethargy– Agitation– Headache– Seizures

HyponatremiaPhysical

• Neurological– Level of alertness – Variable degrees of cognitive

impairment (eg, difficulty with short-term recall; loss of orientation to person, place, or time; frank confusion or depression)

– Focal or generalized seizure activity

– Signs of brainstem herniation• Severe hyponatremia

– Coma;– Fixed, unilateral, dilated

pupil– Decorticate or decerebrate

posturing– Respiratory arrest

• Hydration status – Low volume

• Dry mucous membranes• Tachycardia• Diminished skin turgor• Orthostasis

– Excess free water (hypervolemic)

• Pulmonary rales• S3 gallop• Peripheral edema• Ascites

– Euvolemic• Hypothyroidism• Cortisol deficiency• Syndrome of inappropriate

antidiuretic hormone (SIADH)

HyponatremiaCauses

• Hypovolemic

• Euvolemic

• Hypervolemic

HyponatremiaCauses

• Hypovolemic hyponatremia – Sodium and free water are lost – Replaced by inappropriately hypotonic fluids– Mechanism

• Renal – Acute or chronic renal insufficiency

» Unable to excrete free water– Salt-wasting nephropathy

• Nonrenal route– GI losses– Excessive sweating– Third spacing of fluids (eg, peritonitis, pancreatitis, burns)– Prolonged exercise in a hot environment

HyponatremiaCauses

• Euvolemic hyponatremia – Normal body sodium

• Total body excess of free water• Patients who take in excess fluids.• Psychogenic polydipsia• Administration of hypotonic intravenous • Infants who may have been given inappropriate

amounts of free water

HyponatremiaCauses

• Hypervolemic hyponatremia – Sodium stores increase inappropriately– Acute or chronic renal failure

• Dysfunctional kidneys are unable to excrete the ingested sodium load

– Cirrhosis– CHF– Nephrotic syndrome– Uncorrected hypothyroidism or cortisol deficiency– SIADH– Consumption of large quantities of beer or use of the

recreational drug MDMA (ecstasy)

HyponatremiaLabs

• Questions about lab error– Was the patient's blood sample properly labeled?– Was it obtained from a venous site proximal to an infusion of

hypotonic saline or dextrose in water?– Is laboratory measurement or reporting in error?– If an error is suspected, a second sample should be submitted

for testing before therapeutic measures are initiated.

• Physiological states that show hyponatremia– The most common example is serum hyperglycemia.

• Extracellular glucose induces shift of free water from the intracellular space to the extracellular space.

• Serum sodium is diluted by a factor of 1.6 mEq/L for each 100 mg/dL increase in serum glucose.

HyponatremiaLabs

– A similar phenomenon is observed in patients treated with glycerol or mannitol in an effort to control acute glaucoma or intracranial hypertension. This phenomenon is also seen in patients with advanced renal disease who receive radiocontrast agents for diagnostic testing.

– Hyponatremia may be noted in patients whose serum contains unusually large quantities of protein or lipid.

• In these patients, an expanded plasma protein or lipid fraction leads to a decrease in the plasma water fraction in which sodium is dissolved.

• Laboratory techniques that measure absolute sodium content per unit of plasma water report low sodium levels despite the fact that the concentration of sodium in serum water remains within the normal range.

• This phenomenon, known as pseudohyponatremia, occurs when flame emission spectrophotometry or indirect potentiometry is used to assay serum sodium levels rather than direct potentiometry techniques. This occurs in approximately 60% of US laboratories.

• Serum osmolarity remains undisturbed, and attempts at correcting serum sodium are not indicated.

• Hyperlipidemia that is severe enough to produce pseudohyponatremia almost always is accompanied by a lipemic appearance of the serum sample.

• Hyperproteinemia of sufficient magnitude to induce pseudohyponatremia commonly is due to coexisting multiple myeloma.

HyponatremiaLabs

• Serum osmolarity – Low in hypo-osmolar hyponatremia– Normal in patients with pseudohyponatremia due to hyperlipidemia or hyperproteinemia– Normal or elevated in patients with hyperglycemia.

• Urine sodium levels– Helpful in distinguishing renal causes of hyponatremia from nonrenal causes.– <20

• Hypovolemic hyponatremia • Due to nonrenal causes

– Vomiting– Diarrhea– Fistulas– GI drainage– Third spacing of fluids)– Avid renal absorption of tubular sodium

– >20• Hypovolemic hyponatremia • Due to renal causes• Diuretics• Salt-losing nephropathy• Aldosterone deficiency

HyponatremiaLabs

• Urine osmolarity may be helpful in establishing the diagnosis of SIADH.– Typically, patients with SIADH have inappropriately concentrated

urine with urine osmolarities in excess of 100 mOsm/L.– Patients with other forms of hyponatremia and appropriately

depressed levels of ADH have urine osmolarities below 100 mOsm/L.

• TSH• Adrenal function

– Random serum cortisol levels or – Adrenocorticotropic hormone (ACTH) stimulation test– In patients who have taken oral steroids – or in any patient suspected of having cortisol deficiency

Thank you

• Questions, comments or concerns