Mannitol-induced acute renal failure.

The osmotic diuretic mannitol may be used in diverse clinical settings, such as providing "renal protection" in patients at risk for acute renal failure, decreasing intracranial pressure in patients with intracranial trauma, and preventing the dialysis-disequilibrium syndrome. Mannitol is commonly used after cardiac catheterization, cardiovascular surgery, and exposure to intravenous contrast dyes. This study presents a case in which a long-term renal transplant recipient receiving cyclosporine therapy concomitantly developed acute renal failure after the administration of high-dose mannitol in an attempt to induce an osmotic diuresis. The diagnosis of "osmotic nephrosis" was confirmed by renal biopsy, and the condition was reversed by cessation of the agent. Studies in experimental animals indicate that cyclosporin A can potentiate the tubular toxicity of mannitol, but such an association has not been verified in humans. Numerous studies confirm the nephrotoxic potential of high-dose mannitol, especially in patients with renal insufficiency. The clinical utility of the osmolar gap in preventing mannitol nephrotoxicity is emphasized.