Patients undergoing CABG were randomized to receive either cCPB (n = 13) or mCPB (n = 13). Blood samples were collected preoperatively and 5 times after initiating CPB (up to 5 hours) and analyzed by flow cytometry for intracellular markers of activation (ROS, p38-MAPK, and NF-κB phosphorylation).
ROS in lymphocytes were elevated in cCPB compared with mCPB (p < 0.01), whereas ROS in granulocytes and monocytes were similar between groups. After initiation of CPB, p38-MAPK was higher in patients receiving cCPB compared with those receiving mCPB (p < 0.05). NF-κB phosphorylation in leukocyte subsets was similar in patients exposed to cCPB and those exposed to mCPB. Leukocyte accumulation in cantharidin-induced blisters, white cell counts, and serum C-reactive protein (CRP) was enhanced in response to cardiac operations, but no differences were observed between mCPB and cCPB groups. Postoperative serum creatinine levels were reduced in the mCPB group compared with the cCPB group (p < 0.05).
Both p38-MAPK activation and ROS were attenuated with the use of mCPB compared with cCPB, providing a potential mechanism for reduced inflammation in association with CPB miniaturization.