Imbalance Contributing Factors Signs/Symptoms and Laboratory Findings

Fluid volume deficit (hypovolemia)

Loss of water and electrolytes, as in vomiting, diarrhea, fistulas, fever, excess sweating, burns, blood loss, gastrointestinal suction, and third-space fluid shifts; and decreased intake, as in anorexia, nausea, and inability to gain access to fluid. Diabetes insipidus and uncontrolled diabetes mellitus also contribute to a depletion of extracellular fluid volume.

Acute weight loss, decrease skin turgor, oliguria, concentrated urine, weak rapid pulse, capillary filling time prolonged, low CVP, decrease blood pressure, flattened neck veins, dizziness, weakness, thirst and confusion, increase pulse, muscle cramps, sunken eyes Labs indicate: increase hemoglobin and hematocrit, increase serum and urine osmolality and specific gravity, decrease urine sodium, increase BUN and creatinine, increase urine specific gravity and osmolality

Fluid volume excess (hypervolemia)

Compromised regulatory mechanisms, such as renal failure, heart failure, and cirrhosis; overzealous administration of sodium-containing fluids; and fluid shifts (ie, treatment of burns). Prolonged corticosteroid therapy, severe stress, and hyperaldosteronism augment fluid volume excess.

Acute weight gain, peripheral edema and ascites, distended jugular veins, crackles, elevated CVP, shortness of breath, increase blood pressure, bounding pulse and cough, increase respiratory rate Labs indicate: decrease hemoglobin and hematocrit, decrease serum and urine osmolality, decrease urine sodium and specific gravity

Sodium deficit (hyponatremia) Serum sodium _135 mEq/L

Loss of sodium, as in use of diuretics, loss of GI fluids, renal disease, and adrenal insufficiency. Gain of water, as in excessive administration of DW and water supplements for patients receiving hypotonic tube feedings; disease states associated with

Anorexia, nausea and vomiting, headache, lethargy, dizziness, confusion, muscle cramps and weakness, muscular twitching, seizures, papilledema, dry skin, increase pulse, decrease BP, weight gain, edema Labs indicate: decrease serum

SIADH such as head trauma and oat-cell lung tumor; medications associated with water retention (oxytocin and certain tranquilizers); and psychogenic polydipsia. Hyperglycemia and heart failure cause a loss of sodium.

and urine sodium, decrease urine specific gravity and osmolality

Sodium excess (hypernatremia) Serum sodium _145 mEq/L

Water deprivation in patients unable to drink at will, hypertonic tube feedings without adequate water supplements, diabetes insipidus, heatstroke, hyperventilation, watery diarrhea, burns, and diaphoresis. Excess corticosteroid, sodium bicarbonate, and sodium chloride administration, and salt water near-drowning victims

Thirst, elevated body temperature, swollen dry tongue and sticky mucous membranes, hallucinations, lethargy, restlessness, irritability, focal or grand mal seizures, pulmonary edema, hyperreflexia, twitching, nausea, vomiting, anorexia, increase pulse, and increase BP Labs indicate: increase serum sodium, decrease urine sodium, increase urine specific gravity and osmolality, decrease CVP

Potassium deficit (hypokalemia) Serum potassium _3.5 mEq/L

Diarrhea, vomiting, gastric suction, corticosteroid administration, hyperaldosteronism, carbenicillin, amphotericin B, bulimia, osmotic diuresis, alkalosis, starvation, diuretics, and digoxin toxicity

Fatigue, anorexia, nausea and vomiting, muscle weakness, polyuria, decreased bowel motility, ventricular asystole or fibrillation, paresthesias, leg cramps, decrease BP, ileus, abdominal distention, hypoactive reflexes. ECG: flattened T waves, prominent U waves, ST depression, prolonged PR interval

Potassium excess (hyperkalemia) Serum potassium _5.0 mEq/L

Pseudohyperkalemia, oliguric renal failure, use of potassium-conserving diuretics in patients with renal insufficiency, metabolic acidosis, Addison’s disease, crush injury, burns, stored bank blood transfusions, rapid

Muscle weakness, tachycardia bradycardia, dysrhythmias, flaccid paralysis, paresthesias, intestinal colic, cramps, abdominal distention, irritability, anxiety. ECG: tall tented T waves,

IV administration of potassium, and certain medications such as ACE inhibitors, NSAIDs, cyclosporine

prolonged PR interval and QRS duration, absent P waves, ST depression

Calcium deficit (hypocalcemia) Serum calcium _8.5 mg/dL

Hypoparathyroidism (may follow thyroid surgery or radical neck dissection), malabsorption, pancreatitis, alkalosis, vitamin D deficiency, massive subcutaneous infection, generalized peritonitis, massive transfusion of citrated blood, chronic diarrhea, decreased parathyroid hormone, diuretic phase of renal failure, c PO , fistulas, burns, alcoholism

Numbness, tingling of fingers, toes, and circumoral region; positive Trousseau’s sign and Chvostek’s sign; seizures, carpopedal spasms, hyperactive deep tendon reflexes, irritability, bronchospasm, anxiety, impaired clotting time, decrease prothrombin, diarrhea, decrease BP. ECG: prolonged QT interval and lengthened ST Labs indicate: Decrease Mg⁺⁺

Calcium excess (hypercalcemia) Serum calcium _10.5 mg/dL

Hyperparathyroidism, malignant neoplastic disease, prolonged immobilization, overuse of calcium supplements, vitamin D excess, oliguric phase of renal failure, acidosis, corticosteroid therapy, thiazide diuretic use, increased parathyroid hormone, and digoxin toxicity

Muscular weakness, constipation, anorexia, nausea and vomiting, polyuria and polydipsia, dehydration, hypoactive deep tendon reflexes, lethargy, deep bone pain, pathologic fractures, flank pain, calcium stones, hypertension. ECG: shortened ST segment and QT interval, bradycardia, heart blocks

Magnesium deficit (hypomagnesemia) Serum magnesium _1.8 mg/dL

Chronic alcoholism, hyperparathyroidism, hyperaldosteronism, diuretic phase of renal failure, malabsorptive disorders, diabetic ketoacidosis, refeeding after starvation, parenteral nutrition, chronic laxative use, diarrhea, acute myocardial infarction, heart failure, decreased serum K⁺ and Ca⁺⁺ and certain pharmacologic agents (such

Neuromuscular irritability, positive Trousseau’s and Chvostek’s signs, insomnia, mood changes, anorexia, vomiting, increased tendon reflexes, and increase BP. ECG: PVCs, flat or inverted T waves, depressed ST segment, prolonged PR interval, and widened QRS

as gentamicin, cisplatin, and cyclosporine) __

Magnesium excess (hypermagnesemia) Serum magnesium _2.7 mg/dL

Oliguric phase of renal failure (particularly when magnesium-containing medications are administered), adrenal insufficiency, excessive IV magnesium administration, diabetic ketoacidosis, and hypothyroidism

Flushing, hypotension, muscle weakness, drowsiness, hypoactive reflexes, depressed respirations, cardiac arrest and coma, diaphoresis. ECG: tachycardia bradycardia, prolonged PR interval and QRS, peaked T waves

Phosphorus deficit (hypophosphatemia) Serum phosphorus _2.5 mg/dL

Refeeding after starvation, alcohol withdrawal, diabetic ketoacidosis, respiratory and metabolic alkalosis, decrease magnesium, decrease potassium, hyperparathyroidism, vomiting, diarrhea, hyperventilation, vitamin D deficiency associated with malabsorptive disorders, burns, acid–base disorders, parenteral nutrition, and diuretic and antacid use

Paresthesias, muscle weakness, bone pain and tenderness, chest pain, confusion, cardiomyopathy, respiratory failure, seizures, tissue hypoxia, and increased susceptibility to infection, nystagmus

Phosphorus excess (hyperphosphatemia) Serum phosphorus _4.5 mg/dL

Acute and chronic renal failure, excessive intake of phosphorus, vitamin D excess, respiratory and metabolic acidosis, hypoparathyroidism, volume depletion, leukemia/lymphoma treated with cytotoxic agents, increased tissue breakdown, rhabdomyolysis

Tetany, tachycardia, anorexia, nausea and vomiting, muscle weakness, signs and symptoms of hypocalcemia; hyperactive reflexes; soft tissue calcifications in lungs, heart, kidneys, and cornea

Chloride deficit (hypochloremia) Serum chloride _96 mEq/L

Addison’s disease, reduced chloride intake or absorption, untreated diabetic ketoacidosis, chronic respiratory acidosis, excessive sweating, vomiting, gastric suction, diarrhea, sodium and

Agitation, irritability, tremors, muscle cramps, hyperactive deep tendon reflexes, hypertonicity, tetany, slow shallow respirations, seizures, dysrhythmias, coma Labs indicate: decrease

potassium deficiency, metabolic alkalosis; loop, osmotic, or thiazide diuretic use; overuse of bicarbonate, rapid removal of ascitic fluid with a high sodium content, intravenous fluids that lack chloride (dextrose and water), draining fistulas and ileostomies, heart failure, cystic fibrosis

serum chloride, decrease serum sodium, increase pH, increase serum bicarbonate, increase total carbon dioxide content, decrease urine chloride level, decrease serum potassium

Chloride excess (hyperchloremia) Serum chloride _108 mEq/L

Excessive sodium chloride infusions with water loss, head injury (sodium retention), hypernatremia, renal failure, corticosteroid use, dehydration, severe diarrhea (loss of bicarbonate), respiratory alkalosis, administration of diuretics, overdose of salicylates, Kayexalate, acetazolamide, phenylbutazone and ammonium chloride use, hyperparathyroidism, metabolic acidosis

Tachypnea, lethargy, weakness, deep rapid respirations, decline in cognitive status, decrease cardiac output, dyspnea, tachycardia, pitting edema, dysrhythmias, coma Labs indicate: increase serum chloride, increase serum potassium and sodium, decrease serum pH, decrease serum bicarbonate, normal anion gap, increase urinary chloride level