EVALUATION OF RIGHT-VENTRICULAR FUNCTION DURING AORTIC OPERATIONS

The simultaneous measurements of mixed venous oxygen saturation (Svo2B AR) and right ventricular ejection fraction (RVEF) have now made it po ssible to precisely define and correlate the various hemodynamic chang es that occur during abdominal aortic operations. Twenty-five patients undergoing infrarenal abdominal aortic aneurysm repair were examined with a pulmonary artery catheter capable of continuously measuring Svo 2BAR, and RVEF. With aortic clamping, significant reductions in cardia c index, stroke volume index, and right ventricular end-diastolic volu me index (RVEDVI) were noted, while RVEF remained unchanged. Following unclamping of the aorta, a significant reduction in Svo2BAR occurred, accompanied by an increase in mean pulmonary artery pressure and in p ulmonary vascular resistance. Despite the increase in afterload, RVEDV I and RVEF did not change after unclamping. These preliminary data sug gest that right ventricular function is preserved during abdominal aor tic aneurysm repair.