Disorders and Drugs Associated with Altered Serum Sodium and Extracellular Fluid Levels
Increased Serum Sodium (Hypernatremia)
Total Body Sodium Normal, ECF Volume Low
- Hypovolemia
- Dehydration
- Fever
- Thyrotoxicosis
- Hyperglycemic hyperosmolar nonketotic syndrome
- Diabetes insipidus
- Hyperventilation
- Mechanical ventilation without humidification
Total Body Sodium Increased Proportionately More Than ECF Volume
- Excessive salt ingestion
- Inappropriate or incorrect intravenous therapy with fluids containing sodium
- Cushing's syndrome
- Hyperaldosteronism
- Total Body Sodium Low with ECF Volume Proportionately Lower
- Gastroenteritis
- Osmotic diuresis
- Diaphoresis
- Adrenocorticosteroids
- Methyldopa (Aldomet)
- Hydralazine (Apresoline)
- Reserpine (Serpasil)
- Cough medicines
Decreased Serum Sodium (Hyponatremia)
Total Body Sodium and ECF Volume Low, but Total Body Sodium Proportionately Lower
- Addison's disease
- Salt-losing renal disorders
- Gastrointestinal fluid loss (nasogastric suction, vomiting, diarrhea, fistula, paralytic ileus)
- Diaphoresis
- Diuresis
- Burns
- Ascites
- Massive pleural effusion
- Diabetes ketoacidosis
Total Body Sodium Normal and ECF Volume Normal to High
- Acute water intoxication
- Syndrome of inappropriate antidiuretic hormone secretion
- Glucocorticoid deficiency
- Severe total body potassium depletion
- Total Body Sodium and ECF Volume Increased, but ECF Proportionately Greater
- Acute renal failure with water overload
- Congestive heart failure
- Cirrhosis
- Nephrotic syndrome
- Lithium carbonate
- Vasopressin
- Diuretics (thiazides, mannitol, ethacrynic acid, furosemide)
Adapted from Sacher, RA, and McPherson, RA: Widmann's Clinical Interpretation of Laboratory Tests, ed 11. FA Davis, Philadelphia, 2000, p 401, with permission.