Pathogenesis and prevention of hyponatremic encephalopathy.

Hyponatremia is the most common in-hospital electrolyte abnormality, and it has recently become apparent that there are at least two hyponatremia-associated mechanisms that may induce brain injury. They are hyponatremic encephalopathy and brain damage associated with therapy. The diagnosis of hyponatremia is established easily at virtually no risk to the patient by evaluation of plasma electrolytes. Rapid and appropriate therapy with hypertonic NaCl is indicated prior to respiratory insufficiency to prevent brain damage.