Individualized heparin and protamine management improves rotational thromboelastometric parameters and postoperative hemostasis in valve surgery

Abstract

Objectives: This study investigated whether a tailored approach to heparin and protamine management improved thromboelastometric parameters after cardiopulmonary bypass and reduced postoperative blood loss compared with activated coagulation time (ACT)-based fixed target heparin and protamine management.

Design: Randomized controlled study.

Setting: Tertiary university hospital.

Participants: Patients undergoing elective valve surgery (n = 38).

Interventions: Heparin and protamine management were based either on the ACT (n = 19) or hemostasis management system (HMS) measurements (n = 19; HMS Plus; Medtronic, Minneapolis, MN).

Measurements and main results: The target ACT for initiation of cardiopulmonary bypass was 480 seconds. Study variables included rotational thromboelastometry EXTEM (extrinsic coagulation), HEPTEM (intrinsic coagulation with heparinase), and FIBTEM (fibrin part of clot formation) tests and 24-hour blood loss. The use of HMS reduced the median protamine-to-heparin ratio from 1.00 (1.00-1.00) to 0.62 (0.56-0.66; p<0.001). The ACT group showed a prolonged postbypass clotting time for both EXTEM (86 ± 13 seconds v 78 ± 10 seconds; p = 0.05) and HEPTEM (217 ± 58 seconds v 183 ± 24 seconds; p = 0.03) tests. There was a moderate correlation between protamine dosing with the EXTEM and HEPTEM clotting time (r = 0.42; p = 0.009 and r = 0.38; p = 0.02, respectively). The number of patients with more than 450 mL/24 hours was higher in the ACT than in the HMS group (42% v 12%; p = 0.04).

Conclusions: Individualized heparin and protamine management decreased the protamine-to-heparin ratio, improved postbypass thromboelastometric hemostatic parameters, and reduced the incidence of severe blood loss compared with an ACT-based strategy, supporting the added value of this approach for hemostatic optimization during cardiac surgery.

Keywords: anticoagulation; cardiopulmonary bypass; coagulation; extracorporeal circulation; heparin; protamine; surgical blood loss; thromboelastography.