Failure of cimetidine prophylaxis in neurosurgery.

Three hundred and eight-one patients who underwent major neurosurgical procedures were given cimetidine prophylaxis against stress ulceration. Nine patients (2.4%) developed acute gastrointestinal complications; two patients had perforation and bleeding from gastroduodenal ulcers, and seven patients had bleeding alone. Six of these patients, all above the age of 70 years, died as a consequence of the complication. Univariate analysis showed that four variables--state of consciousness, syndrome of inappropriate secretion of antidiuretic hormone, nature of surgery, and age--were significant factors in predicting cimetidine failure. Multivariate analysis revealed that a patient's pre-operative state of consciousness and the presence of inappropriate secretion of antidiuretic hormone were of independent significance in predicting cimetidine failure. The risk was 52% and 0.07%, respectively, when both factors were either present or absent.