BivaLirudin versUS Heparin in Extracorporeal Membrane Oxygenation

The goal of this open label randomised clinical trial is to compare Bivalirudin versus Heparin for anticoagulation in patients requiring extracorporeal membrane oxygenation support. The main question it aims to answer are include the ability to maintain anticoagulation within defined therapeutic range, bleeding and thrombotic complications and a comparison of the total cost of anticoagulation care. Participants will be randomised to either anticoagulation with Bivalirudin or anticoagulation with Unfractionated Heparin.

Rationale: Anticoagulation whilst on extracorporeal membrane oxygenation (ECMO) is required. Bleeding and thrombotic complications whilst on ECMO are common and may effect the patient outcome. The optimal anticoagulant for ECMO patients is not clear and there exists no randomised control trial data comparing anticoagulants on ECMO. This Phase 2b trial will provide data to enable larger definitive phase III trials to determine the best anticoagulant whilst on ECMO. Hypothesis: Hypothesis: In adults ECMO patients'; anticoagulation with Bivalirudin results in more samples within therapeutic range than unfractionated Heparin. Total anticoagulation costs with Bivalirudin are similar to unfractionated Heparin. The objectives of this study is to assess anticoagulation protocol of bivalirudin versus unfractionated heparin and assess the to the cost of each protocol.

INCLUSION CRITERIA * Patients receiving ECMO * Age: 18 years or older * Ability to randomise the patient within 4 hours of ECMO support initiation EXCLUSION CRITERIA * Post-cardiotomy ECMO patients * Contraindication to heparin or bivalirudin at time of randomisation e.g., active bleeding * Heparin induced thrombotic thrombocytopenia syndrome * Where the patient is expected to be disconnected from ECMO in the next day after cannulation. * Limitations of care put in place either through patient wishes or the treating medical teams * Other reason where the treating physician deems the study is not in the patient's best interest * Patients who are suspected or confirmed to be pregnant * Inherited bleeding or thrombotic disorders, Systemic Lupus Erythematosus patients