Effect of acute plateletpheresis and back-transfusion on platelet activation in patients undergoing open heart surgery with CPB

Abstract

Objective To evaluate the effect of acute plateletpheresis(APP) and back-transfusion on platelet activation in the patients undergoing open heart surgery with cardiopulmonary bypass(CPB). Methods Forty patients, aged 35-64 yr, with body mass index within the normal range, of ASA physical status Ⅱ or Ⅲ(NYHA Ⅱ or Ⅲ), scheduled for elective cardiac valve replacement under CPB, were randomly divided into 2 groups(n=20 each) using a random number table: control group(group C)and APP group.In group APP, after induction of anesthesia, APP was performed, packed red blood cells and platelet-poor plasma were transfused back to the patient after termination of the previous cycle, and another cycle was started simultaneously.Platelet-rich plasma(PRP)was harvested and transfused back to the patient after termination of CPB and neutralization of heparin with protamine.Before induction of anesthesia(baseline), after APP and before heparinization, after neutralization of heparin with protamine and before back-transfusion of PRP, at the end of operation, and at 24 h after operation, venous blood samples were collected for determination of the expression of CD62p and PAC-1 in inactivated platelets and activated platelets by adenosine diphosphate(ADP). After APP and before heparinization, and after neutralization of heparin with protamine and before back-transfusion of PRP, the expression of CD62p and PAC-1 in inactivated platelets and ADP-activated platelets was detected in the whole blood and PRP in group APP. Results Compared with C group, the expression of CD62p and PAC-1 in inactivated platelets was down-regulated at the end of operation, and the expression of CD62p and PAC-1 in ADP-activated platelets was up-regulated in APP group.The expression of CD62p and PAC-1 in inactivated platelets was down-regulated in PRP, and the expression of CD62p and PAC-1 in ADP-activated platelets was up-regulated in PRP as compared with those in the whole blood. Conclusion APP can not induce platelet activation, however, platelet back-transfusion can enhance platelet activation in the patients undergoing open heart surgery with CPB. Key words: Plateletpheresis; Platelet activation; Cardiopulmonary bypass; Cardiac surgical procedures