COMPLEMENT AND NEUTROPHIL ACTIVATION DURING CARDIOPULMONARY BYPASS - A RANDOMIZED COMPARISON OF HYPOTHERMIC AND NORMOTHERMIC CIRCULATION

Objective: Activation of both complement and neutrophils has been demo nstrated to be involved in many pathological reactions following cardi opulmonary bypass (CPB). The aim of the present study is to evaluate t he effect of normothermic and hypothermic CPB on both complement and n eutrophil activation. Methods: Two groups of patients (n = 20 each) sc heduled for elective coronary artery bypass grafting, underwent CPB wi th intermittent warm or cold blood cardioplegia. Plasma concentration of C3a, C5a and C5b-9, as well as nitro-blu tetrazolium (NBT) scores o f circulating neutrophils were measured before anesthesia, 10 and 30 m in after the beginning of CPB, and 8, 16 and 24 h, postoperatively. Re sults: In both groups, CPB determined a significant complement activat ion, evidenced as a significant increase in plasma concentration of C3 a, C5a and C5b-9. This in turn triggered the neutrophil activation, do cumented as a significant increase of NTB scores in circulating neutro phils at the end of CPD and in the early postoperative period. Interes tingly, in the warm group the extent of both complement and neutrophil activation was significantly higher compared with the cold group duri ng the whole sampling period. Conclusions: In conclusion, our study cl early demonstrates that warm CPB is associated with an increased abili ty to activate complement and neutrophils in patients undergoing coron ary surgery. Copyright (C) 1997 Elsevier Science B.V.