Cerebral edema complicating nonketotic hyperosmolar coma

Cerebral edema as a complication of the therapy of diabetic coma has been described for over 50 years, although modern awareness dates to about 1967. Almost all cases have occurred in patients with diabetic ketoacidosis (DKA). Although a few cases of cerebral edema have been reported in patients with nonketotic hyperosmolar coma (NKHC), these are in general not well documented by either autopsy data of cat scans. Over a period of 9 years, I have encountered 5 patients who developed cerebral edema as a complication of the therapy of NKHC. The initial plasma glucose in these patients was 1,496 +/- (SD) 296 mg/dl and plasma osmolality was 382 +/- 29 mosm/kg. All had depression of sensorium to at least a stupor (stage I coma or greater). All were treated with intravenous insulin and either 77 or 154 mM NaCl, and plasma glucose fell at a mean rate of 38 mg/dl/h. In all patients, plasma glucose fell below 250 mg/dl (mean of 18 +/- 66 mg/dl) and all patients experienced increased depression of sensorium, elevated csf pressure, and brain swelling as diagnosed by cat scanning. Therapy with various combinations of glucose, mannitol and steroids were without effect. In 1 patient, insertion of a subdural intracranial screw lowered intracranial pressure from 24 to 3 cm of H2O. Three of the 5 patients died and 2 remain in a persistent vegetative state, 1 of whom is also quadriplegic.(ABSTRACT TRUNCATED AT 250 WORDS)