Disorders of Water and Sodium Balance: Hypernatremia

Hypernatremia is an electrolyte disorder most prevalent in the elderly and the critically ill, with over 60% of cases developing over the course of an inpatient stay. Characterized by elevated serum sodium concentrations, this disorder is manifested either by pure-water loss without replacement, or excessive sodium intake without appropriate water balance. Left untreated it may lead to seizures and coma. General treatment in the case of severe hypernatremia is infusion of isotonic saline followed by pure-water after the patient is stabilized. Further treatment of the underlying cause may involve diuretics, thiazides, and a variety of other medications in conjunction with dietary and lifestyle modifications. This review offers an overview of various disorders of water balance: diabetes insipidus, nephrotic syndrome, cirrhosis, idiopathic edema, and volume depletion, as well as their clinical presentations, lab tests, and management. This review contains 1 figure, 1 table, and 25 references. Key words: Hypernatremia, Edematous States , Diabetes insipidus, Volume Depletion, Cirrhosis, Diuretics