Hemodynamic and metabolic effects of abdominal aortic crossclamping

The hemodynamic and metabolic effects of aortic crossclamping and declamping were studied in 10 patients undergoing abdominal aortic reconstructive surgery. After placement of pulmonary and radial arterial catheters, measurements were obtained preoperatively, during the procedure according to protocol, and postoperatively. Pulmonary arterial wedge pressure was maintained at 10 to 15 mm Hg throughout the operation. Aortic cross clamping produced a significant increase in systemic arteriolar resistance and systolic blood pressure, with no change noted in the left ventricular stroke work index. Declamping decreased systemic resistance and produced no change in the left ventricular stroke work index. Clamping and declamping resulted in elevations of serum lactate. Central venous pressure correlated with pulmonary arterial wedge pressure in each patient and in the entire group. Cardiac function is not decreased by aortic crossclamping, and central venous pressure can usually be used for hemodynamic monitoring in these patients.