The Influences of Perfusion Temperature on Inflammatory and Hematologic Responses during Cardiopulmonary Bypass

Kim, Sang Pil; Choi, Seok Cheol; Park, Dong Wook; Han, Il Yong; Hwang, Yoon Ho; Lee, Yang Haeng; Cho, Kwang Hyun

Abstract

BACKGROUND: Several studies have demonstrated that conventional hypothermic cardiopulmonary bypass (CPB) causes cellular injury, abnormal responses in peripheral vascular beds and increased postoperative bleeding, whereas normothermic CPB provides protection of the hypothermic-induced effects and better cardiac recovery. The present study was prospectively performed to compare the effects of normothermic CPB to those of hypothermic CPB on the inflammatory and hematologic responses during cardiac surgery. MATERIAL AND METHOD: Thirty-four adult patients scheduled for elective cardiac surgery were randomly assigned to hypothermic CPB (nasopharyngeal temperature 26~28degreesC, n=17) or normothermic CPB (nasopharyngeal temperature>35.5degreesC, n=17) group. In both groups, cold (4degreesC) crystalloid cardioplegia was applied for myocardial protection. Blood samples were drawn from radial artery before (Pre-CPB), 10 minutes after starting (CPB-10) and immediately after ending (CPB-OFF) CPB. Total leukocyte and platelet counts, interleukin-6 (IL-6) level(expressed as percent to the baseline of Pre-CPB), D-dimer level, protein C and protein S activity were measured with the blood samples. The amount of bleeding for postoperative 24 hours and blood transfusion after operation were also assessed. All parameters were compared between the two groups. RESULT: The total leukocyte counts (10,032+/-65/mm3) and the increased ratio of IL-6 (353+/-7.0%) at CPB-OFF in the normothermic group were higher than that (7,254+/-48/mm3 and 298+/-7.3%) of the hypothermic group(p=0.02 and p=0.03). In the normothermic group, protein C activity (32+/-3.8%) and protein S activity (35+/-4.1%) at CPB-OFF were significantly lower than that (45+/-4.3% and 51+/-3.8%) of the hypothermic group (p=0.04 and p=0.009). However, there were no differences in platelet counts and D-dimer concentration. In the normothermic group, the amount of bleeding for postoperative 24 hours (850+/-23.2 mL) and requirements for blood transfusion after operation such as packed cell (1,402+/-20.5 mL), fresh frozen plasma (970+/-20.8 mL) and platelet (252+/-6.4 mL) were higher than that (530+/-21.5 mL, 696+/-15.7 mL, 603+/-18.2 mL and 50+/-0.0 mL) of the hypothermic group.
CONCLUSION
These results indicate that normothermic CPB with cold crystalloid cardioplegia was associated with higher increase in inflammatory response, hemostatic abnormalities and postoperative bleeding problem than moderate hypothermic CPB.