The management of hyponatremic emergencies.

Given time, the brain can tolerate extraordinarily severe hyponatremia, but it does not take well to sudden changes; both rapid onset and rapid correction of hyponatremia can be injurious. Emergency treatment of hyponatremia should be reserved for the patient who has not had time to fully adapt to the disturbance. When the clinical situation demands it, treatment can be safely initiated by infusing 3% saline at 1 to 2 mL/kg/hour for 2 to 3 hours. Once the emergency has passed, more conservative measures can be substituted so that the overall rate of correction does not exceed 12 mEq/L/day. Limiting therapy in this manner avoids the osmotic demyelination syndrome, a complication of overly rapid correction of hyponatremia.