Cardiovascular Responses to Clamping of the Aorta during Epidural and General Anesthesia

32 male patients undergoing reconstructive aortic surgery

Lumbar epidural blocks with bupivacaine and nitrous oxide in oxygen, or general anesthesia with morphine (2 mg/kg) and nitrous oxide, combined with Ringer's lactate to maintain mean pulmonary capillary wedge pressure 3 to 4 torr above pre-anesthetic values

Same anesthesia regimens combined with Ringer's lactate to maintain pulmonary capillary wedge pressure similar to pre-anesthetic values

Cardiovascular responses (mean arterial blood pressure, systemic vascular resistance, cardiac output, pulmonary capillary wedge pressure, and pulmonary vascular resistance) during aortic cross-clamping and declampingsurrogate