Suppression of the inflammatory response to cardiopulmonary bypass

The inflammatory response to major surgery, especially cardiac surgery using cardiopulmonary bypass (CPB) is now a well established entity. A whole body inflammatory response can lead to severe organ dysfunction, postoperative bleeding disorders, respiratory distress syndrome and sometimes death. There is, however, controversy over various methods and their efficacy towards suppression of this response. We studied forty consecutive patients undergoing coronary artery bypass grafting (CABG) using CPB. Ten patients in group A served as control while ten patients in group B received piroxicam, a non steroidal anti-inflammatory drug (NSAID). Ten patients in group C received aprotinin, a kallikrein inhibitor and ten patients in group D underwent haemofiltration during CPB. Inflammatory response by way of increase in total white blood cell (WBC) count (p<0.007), decrease in lymphocyte count (p<0.005), increase in C-reactive protein (CRP, p <0.005) was observed in all four groups at 24 hour after CPB. A decrease in complement C3 and C4 (p<0.01) was observed in groups A and C at 24 hours after CPB. The response observed was not severe enough to cause any organ damage in any group. None of the methods studied could effectively suppress the inflammatory response to CPB but the response was altered in some way by each method.