22: Is Bivalirudin a Better Anticoagulant for Extracorporeal Membrane Oxygenation (ECMO) Patients? A Case Series

Background: Extracorporeal membrane oxygenation requires effective and reliable anticoagulation to prevent thrombosis and bleeding complications. Unfractionated heparin remains the most commonly used anticoagulant but is associated with variable pharmacodynamics, bleeding risk, and heparin induced thrombocytopenia. Bivalirudin is a synthetic direct thrombin inhibitor with predictable pharmacokinetics, a short half life, independence from plasma cofactors, and no risk of heparin induced thrombocytopenia. These properties make it a promising alternative anticoagulant for extracorporeal membrane oxygenation. Methods: We conducted a retrospective review of 10 patients supported on extracorporeal membrane oxygenation, including 4 adults and 6 pediatric patients, who received bivalirudin for anticoagulation due to severe respiratory failure. Bivalirudin infusions were initiated at 0.05 to 0.1 mg per kg per hour and titrated to achieve an activated partial thromboplastin time of 45 to 60 seconds and an activated clotting time of 180 to 240 seconds. Serial monitoring of coagulation parameters, platelet counts, fibrinogen levels, D dimer, and markers of hemolysis was performed. Dose adjustments were guided by renal function and bleeding risk. Results: Eight patients survived to extracorporeal membrane oxygenation decannulation and hospital discharge, including all pediatric patients. Stable anticoagulation was achieved with minimal variability in activated partial thromboplastin time and activated clotting time. No cases of heparin induced thrombocytopenia, major thromboembolic events, oxygenator failure, or circuit exchange were observed. Platelet counts remained stable throughout therapy. Two patients experienced minor bleeding episodes that resolved with conservative management. Compared with institutional historical data for heparin, transfusion requirements appeared lower and extracorporeal support duration shorter, although no formal statistical comparison was performed. Conclusion: Bivalirudin provided safe, effective, and consistent anticoagulation during extracorporeal membrane oxygenation with low complication rates and no incidence of heparin induced thrombocytopenia. These findings support its use as an alternative to heparin, although larger prospective controlled studies are needed to define optimal dosing and monitoring strategies.