Objective: To compare the heparin reversal effect among three differential protamine doses in 1:1 ratio based on initial heparin dose (group 1), initial plus additional heparin dose (group 2), and total heparin dose (group 3) in patients undergoing cardiopulmonary bypass [CPB] surgery.

Materials and Methods: A retrospective review and follow up study was conducted in adult patients undergoing CPB surgery at a tertiary university hospital. The initial heparin dose, additional heparin dose, total heparin dose, protamine dose, baseline activated clotting time [ACT] and ACT after heparin reversal were obtained. Effective heparin reversal was defined as post reversal ACT within 10% of the baseline ACT value or between 80 to 150 seconds.

Results: Five hundred CPB surgical patients were included in the present study. Effective heparin reversal was achieved in 47.2%, 45.1%, and 55.6% of patients in groups 1, 2, and 3, respectively (p = 0.17). There was no difference in amount of blood loss and blood transfusion in 24 hours postoperatively.

Conclusion: There was no difference in effectiveness of heparin reversal, postoperative bleeding, and postoperative blood transfusion among these three differential protamine doses.

Keywords: Cardiac surgery, Dose, Heparin, Protamine