Dialysis dysequilibrium syndrome in neurosurgical patients.

Four neurosurgical patients with acute renal failure are presented. Intracranial pressure (ICP), cerebrospinal fluid (CSF) osmolality, and plasma osmolality were measured before, during, and after hemodialysis. There was an increase in ICP during all six hemodialyses performed on these patients. An osmolality gradient was established between the plasma and the CSF during four hemodialyses performed on two patients but not during one hemodialysis on one other patient. Continuous ventricular drainage and ICP monitoring were simple and effective clinical methods to avoid irreversible herniation during hemodialysis in these patients. A review of the literature on, proposed pathogenesis of, and prophylactic possibilities for dialysis dysequilibrium syndrome in neurosurgical patients is presented.