Influence of Cardiopulmonary Bypass on Some Host Defence Functions in Man

Abstract
Four different functions of the immune defense were studied in 6 men undergoing open-heart surgery with cardiopulmonary bypass (CPB). Preoperatively, a few hours after and 3 days after surgery tests were performed as follows: in vivo phagocytic and metabolic functions of the RES, hemolytic activity of blood monocytes, nitroblue tetrazolium (NBT) reduction by granulocytes and bactericidal capacity of granulocytes. Compared to the preoperative values, the RES functions were unchanged postoperatively, and there was a significant increase in the hemolytic activity of monocytes and in the NBT reduction of granulocytes. The capacity of the granulocytes to kill bacteria was normal a few hours after surgery, but significantly increased on day 3. No infectious complications occurred and all patients recovered uneventfully. Apparently open heart surgery under CPB is accompanied by an increased activity of granulocytes and monocytes in the early postoperative period.