Complement and neutrophil activation during cardiopulmonary bypass: a randomized comparison of hypothermic and normothermic circulation.
OBJECTIVE
Activation of both complement and neutrophils has been demonstrated to be involved in many pathological reactions following cardiopulmonary bypass (CPB). The aim of the present study is to evaluate the effect of normothermic and hypothermic CPB on both complement and neutrophil activation.


METHODS
Two groups of patients (n = 20 each) scheduled for elective coronary artery bypass grafting, underwent CPB with intermittent warm or cold blood cardioplegia. Plasma concentration of C3a, C5a and C5b-9, as well as nitro-blu tetrazolium (NBT) scores of circulating neutrophils were measured before anesthesia, 10 and 30 min after the beginning of CPB, and 8, 16 and 24 h, postoperatively.


RESULTS
In both groups, CPB determined a significant complement activation, evidenced as a significant increase in plasma concentration of C3a, C5a and C5b-9. This in turn triggered the neutrophil activation, documented as a significant increase of NTB scores in circulating neutrophils at the end of CPB and in the early postoperative period. Interestingly, in the warm group the extent of both complement and neutrophil activation was significantly higher compared with the cold group during the whole sampling period.


CONCLUSIONS
In conclusion, our study clearly demonstrates that warm CPB is associated with an increased ability to activate complement and neutrophils in patients undergoing coronary surgery.
Chello
M
M
Department of Cardiac Surgery, Medical School of Catanzaro, Italy.
Mastroroberto
P
P
Romano
R
R
Ascione
R
R
Pantaleo
D
D
De Amicis
V
V
D000328:Adult; D000368:Aged; D002315:Cardiopulmonary Bypass; D003167:Complement Activation / Q000276:immunology*; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000276:immunology / Q000601:surgery*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008875:Middle Aged; D018375:Neutrophil Activation / Q000276:immunology*; D011183:Postoperative Complications / Q000276:immunology