Blood transfusion requirements in coronary artery surgery with and without the activated clotting time (ACT) technique

Summary Control of anticoagulation during cardiopulmonary bypass (CPB) with the automated activated whole blood clotting time (ACT) and reversal of heparin after CPB using a computerized ACT dose-response curve method resulted in significant reductions of blood transfusion requirements, surgical time, and protamine doses in 150 patients undergoing coronary artery bypass grafting procedures (ACT group) as compared to 200 patients for whom a standard fixed dose protocol for heparin and protamine was used (control patients). Mean transfusion requirements were 1,938±60 SEM ml whole blood and 853±48.3 SEM ml red blood cells for control patients and 1,397±59 SEM ml whole blood (P<0.001) and 695±34 SEM ml red blood cells (P<0.01) in the ACT group. ACT group patients also required less protamine with 26.2±0.60 SEM ml Protamine 1,000 (Roche) as compared to 33.9±0.49 SEM ml for control patients (P<0.001) but more heparin with 31,440±783 SEM I.U. versus 26,760±263 SEM I.U. (P<0.001). Surgical time decreased from 321±5.5 SEM min for control patients to 289±5.4 SEM min for ACT group patients (P<0.001).Abbreviations AB autologous blood - ACD right coronary artery - ACT activated clotting time - ACT_o ACT — before heparin administration - ACT₃₆₀ ACT — 5 min. after 360 I.U. heparin/kg body wt. - CPB cardiopulmonary bypass - Cx circumflex branch of the left coronary artery - DIAG diagonal branch of the left coronary artery - ECC extracorporeal circulation - FB fresh blood - FFP fresh frozen plasma - POD postoperative day - RBC red blood cells - RIA descending branch of the left coronary artery - RIP posterior descending branch of the right coronary artery - WB whole blood