Abstract
We experienced two aged cases of hyperkalemia resulting from the administration of mannitol. In both cases, prominent hyperkalemia developed following administration of 500ml of mannitol during clipping operations for cerebral aneurysm. The blood potassium levels rose to 6.27 mEq•l-1 and 6.20 mEq•l-1 in case 1 and case 2, respectively. Since neither of the patients had notable metabolic acidosis, the hyperkalemia was caused by the following administration of mannitol: a rise in plasma osmotic pressure, resulting in release of intracellular fluid and the accompanying transfer of intracellular potassium to the extracellular fluid. Thus, electrolyte levels should be periodically checked when using mannitol.
