Bivalirudin Anticoagulation in Extracorporeal Membrane Oxygenation (ECMO) for Severe Coronaviral Disease (COVID-19) Related Acute Respiratory Distress Syndrome (ARDS)

PURPOSE: ECMO as a bridge, is a potential option in patients with severe COVID-19 who develop respiratory failure despite maximal conventional therapy. Heparin has been the standard anticoagulant, but is associated with bleeding and thrombocytopenia. Bivalirudin has been successfully used as an alternative in cases of heparin induced thrombocytopenia (HIT). We evaluated Bivalirudin as an anticoagulant in COVID-19 patients on ECMO who develop HIT or had persistent thrombocytopenia despite multiple platelet transfusions. METHODS: After institutional clearance, we performed retrospective analysis of all the COVID-19 related ECMO managed in our centre between January to August 2021. Femoral vein to internal jugular vein ECMO was instituted in all these patients and anticoagulation targets were monitored daily as per institutional protocols. We compared incidence of ECMO circuit and oxygenator changes, post procedural bleeding and the number of blood products transfused between the Heparin and Bivalirudin group. Descriptive analysis was carried out by mean and standard deviation. The mean values were compared using student t-test and categorical outcomes using Chi square test. RESULTS: Total of 42 COVID-19 ARDS related ECMO were managed in our centre during the study period. 8 patients were switched to Bivalirudin, as 2 patients were diagnosed with HIT and 6 had persistent thrombocytopenia despite multiple platelet transfusions. In patients with HIT, the platelet count improved by 72 hours. The incidence of post tracheostomy and intercostal drain insertion bleed was statistically higher in Heparin group (p <0.05). Total number of packed cell transfusion was significantly less in Bivalirudin group but platelet transfusion was lower, though not statistically significant. The usage of fresh frozen plasma and cryoprecipitate were similar. The rates of ECMO oxygenator and circuit exchanges were comparable with mean duration of 13.5 days for change from the date of initiation. CONCLUSION: Bivalirudin is a feasible alternative anticoagulant in the COVID-19 ECMO with the benefit of lower rates of bleeding and consequent need for transfusion. Further large studies are needed to assess the efficacy and benefits of direct thrombin inhibitors as a practical and safe substitute to Heparin in these situations.