Low Versus Standard Intensity Heparin Protocols in Adults Maintained on Extracorporeal Membrane Oxygenation: A Retrospective Cohort Study

Background: Patients maintained on extracorporeal membrane oxygenation (ECMO) often require systemic anticoagulation to prevent circuit clotting and systemic thromboembolic complications. The optimal intensity of anticoagulation to balance the risk of bleeding and prevention of thrombotic complications in this patient population is not well described. Objective: To compare bleeding events in patients on ECMO anticoagulated with standard vs low intensity heparin protocols. Methods: This single-center, retrospective cohort study included adult patients on VA- or VV-ECMO and anticoagulated with low or standard intensity heparin protocols. The primary outcome was the incidence of major bleeding; secondary outcomes included the incidence of minor bleeding, thrombotic complications, heparin-induced thrombocytopenia, in-hospital mortality, time in therapeutic range, anti-Xa correlation with aPTT, intensive care unit and hospital lengths of stay, oxygenator exchanges, and rate of protocol switching. Results: A total of 27 patients (14 low intensity, 13 standard intensity) were included. There were six major bleeding events in the low intensity group and four in the standard intensity group (P = 0.69); there were four minor bleeding events in the low intensity group and five in the standard intensity group (P = 0.69). Seven patients in the standard intensity group switched protocols; zero patients in the low intensity group switched protocols (P = 0.002). There were no differences in any other outcomes. Conclusions: There was no difference in the incidence of any bleeding or thrombotic events when using a low vs standard intensity heparin protocol in patients on ECMO. A low intensity heparin strategy for patients on ECMO may be feasible and safe.