Mannitol-induced rebleeding from intracranial aneurysm. Case report.

A case is presented in which rebleeding from an intracranial saccular aneurysm occurred a few minutes after intravenous administration of mannitol during surgery. The relationship between the reducing effect of mannitol on elevated intracranial pressure and the increased pressure gradient across the aneurysm wall, causing risk of rebleeding, is discussed. Procedures that can reduce this risk are summarized.