A comparison of activated coagulation time-based techniques for anticoagulation during cardiac surgery with cardiopulmonary bypass.

OBJECTIVE: The inadequacy of heparinization during cardiopulmonary bypass (CPB) can lead to hemostatic activation with increases in postoperative blood loss and blood product requirements after cardiac surgery. Because activated coagulation time (ACT) measurements may not be accurate during CPB, the use of a heparin management system (HMS) has been advocated. This study compared the efficacy of a modified ACT-based system versus an HMS (Hepcon; Medtronic Inc, Minneapolis, MN) for CPB anticoagulation. DESIGN: Randomized controlled trial. SETTING: Regional cardiac surgery center. PARTICIPANTS: Adult elective cardiac surgical patients. INTERVENTIONS: Patients allocated to the HMS group (HC) received individualized heparin doses as indicated by the Hepcon system. Patients in the modified ACT group (C) received a standard weight-based heparin bolus with further doses as dictated by the ACT (Max-ACT, Helena Labs, Sunderland, UK). In addition, group C received supplemental heparin, independent of the ACT, as dictated by the volume of crystalloid added to the extracorporeal circuit. Outcome measures examined were hemostatic activation, postoperative chest tube loss, and blood product requirements. RESULTS: This study showed no significant difference in efficacy between the modified ACT and HMS heparinization strategies. Although the HC group received significantly greater amounts of heparin, this did not reduce hemostatic activation, postoperative blood loss, or transfusion requirements. CONCLUSION: ACT-based heparinization was found to be as efficacious as the Hepcon HMS system.