COMPARISON OF ANESTHESIA WITH DIAZEPAM AND KETAMINE VS MORPHINE IN PATIENTS UNDERGOING HEART-VALVE REPLACEMENT

Due to its analgesic and amnesic effects, ketamine has potential advantages as a primary agent for patients undergoing open-heart surgery. The undesirable positive inotropic and chronotropic effects associated with ketamine have deterred its use. Diazepam pretreatment appears to block these unwanted effects. Randomly selected patients (16) were given a combination of diazepam, 0.4 mg/kg, followed by ketamine, 2 mg/kg, and N2O, 50%. The circulatory responses to induction, intubation and operation with those obtained in a matched group of patients who received morphine, 3 mg/kg, and N2O, 50%, were compared. All patients underwent mitral- or aortic-valve replacement. Circulatory responses were not significantly different between the 2 groups. In both groups, heart rate, mean arterial blood pressure and rate-pressure product increased significantly with intubation of the trachea, incision of the skin and sternotomy. The incidences of hypertension, hypotension and arrhythmias and the need for inotropic drugs were not significantly different between the 2 groups. No intraoperative awareness occurred in either group. Apparently diazepam-ketamine anesthesia is a satisfactory alternative to morphine anesthesia for patients undergoing heart-valve replacement.