HYPONATREMIA

Hyponatremia refers to the condition in which body’s sodium is <135mEq/L
Si/Sx: confusion, convulsion, fatigue, irritability, coma, headache, vomiting

Cause:

Pseudohyponatremia: Every 100mg/dl glucose above the normal limit, decrease sodium by 1.6 mEq/L
Hypervolemia: CHF, cirrhosis, nephrotic syndrome
Hypovolemia: diarrhea, vomiting, sweating, renal insufficiency, low aldosterone
Euvolemic: hypothyroidism, psychogenic, polydipsia, SIADH, oxytocin

Treatment:

If the patient is stable, then restriction the water intake to 1 L/day

If the patient is confused or has mild symptoms, then give normal saline and loop diuretics

If the patient has severe symptoms (seizure, coma), then give 3 % hypertonic saline, but don’t exceed >0.5mEq/hour or 12mEq in a day otherwise patient may develop central pontine myelinolysis

A stable patient with pseudohyponatremia is treated by correcting the glucose level


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