Orally administered diazepam (0.35 mg/kg) was given as premedication and induction of anesthesia consisted of fentanyl (50 M-g/kg), diazepam (0.25 mj^ kg) and pancuronium (0.1 mg/kg). Anesthesia was maintained with increments of fentanyl and diazepam. Artificial ventilation was provided by a Servo ventilator A (Siemens-Elema, Germany) (n = 10/ min, Vt= 10 ml/kg, oxygen = 100 percent). Radial artery and pulmonary artery Swan-Ganz catheters were inserted prior to induction with the patient under local anesthesia. Central temperatures were monitored through rectal and pulmonary artery catheter probes. Ringers lactated solution and vasodilators (nitroglycerin, sodium nitroprusside) were administered as needed. No dextrose was administered throughout surgery except 820 mg per blood unit.
Cardiopulmonary bypass
After injection of heparin (300 U/kg), the venous cannula was inserted into the right atrium and the arterial cannula into the root of the ascending aorta. The patients were allocated to one of two groups according to the surgeons routine: group 1 (n = 12) underwent hypothermic CPB (injection temperature = 25°C) and group 2 (n = 10) underwent normothermic CPB (injection tempera-ture=37°C).