[Severe hypernatremia: survival without neurologic sequelae].

Hypernatremia is an electrolyte disturbance most frequently caused by excess water loss and less frequently by increased sodium intake. The few reported cases of severe hypernatremia (> 190 mEq/l) had an adverse outcome with high mortality and/or severe neurologic sequelae. The first case was a 7-year-old girl with renal failure undergoing continuous venovenous hemodiafiltration therapy who presented hypernatremia (216 mEq/l) after incorrect preparation of dialysis fluid. The patient was treated with hemodiafiltration and hypernatremia was resolved in 48 hours. She had a convulsive crisis without subsequent neurologic impairment. The second patient, a 3-year-old girl with pseudohypoaldosteronism type I and encephalopathy, had hypernatremia (203 mEq/l) due to erroneous sodium administration, which was corrected in 36 hours with intravenous fluid therapy. Her neurologic status was unchanged by treatment. We conclude that children with extreme hypernatremia survive without neurologic sequelae if treatment achieves a progressive decrease of natremia.