Mannitol intoxication in patients with renal failure.

Eight patients with severe mannitol intoxication were treated during the last ten years. These patients had CNS involvement out of proportion to uremia, severe hyponatremia, a large osmolality gap (high measured minus calculated serum osmolality), and fluid overload. Six patients were treated with hemodialysis and one patient received peritoneal dialysis. One patient died before any treatment could be started. Mannitol had a half-life of approximately 36 hours during the intervals without treatment. The ideal treatment is hemodialysis that rapidly removes mannitol (half-life, six hours) and replaces it with sodium; peritoneal dialysis removed mannitol slowly (half-life, 21 hours).