High Rate of Hemorrhagic Complications in COVID-19 Patients Requiring ECMO Support in Spite of Conservative Anticoagulation Strategies

ABSTRACT

Background: Increased rate of thrombotic events have been described in severe COVID-19 disease leading to liberal anticoagulation strategies in patients requiring ECMO support, which might be associated to increased risk of hemorrhagic complications. We present our experience with a conservative anticoagulation approach. Objectives and Methods: Data of eight COVID-19 patients requiring veno-venous (VV) ECMO support between 3/1-8/20/20 was retrospectively analyzed. All patients received anticoagulation with IV heparin with therapeutic target PTT 50-70 seconds. Primary goal was incidence of major hemorrhagic complications, and secondary goals to determine relationship to anticoagulation range, and patient clinical outcome. Results: Mean age was 52 years (36-62). Six (75%) patients were male. Patients received ECMO support for 25 days (10-39). Therapeutic anticoagulation range was achieved 33% (24-49%) of the time, while patients remained sub-therapeutic (PTT<50") 63%, and supratherapeutic (PTT>70") 3% of the time. INR was normal (<1.2) in all patients, and thrombocytopenia (platelet count < 100,000) was observed in 3 patients (37.5%). Major bleeding complications included cerebral in 4 (50%), oro-pharyngeal in 2 (25%), and spontaneous psoas hematoma in 2 (25%) patients. No clear correlation was observed between supratherapeutic anticoagulation and development of hemorrhagic complications. Seven ECMO circuits were exchanged in 6 patients at 13.5 days (9-19). Four (50%) patients were decannulated, and 3 (37.5%) discharged from the hospital alive. Conclusions: Conservative anticoagulation strategies during V-V ECMO support for COVID-19 led to high rate of ECMO circuit exchange but did not prevent hemorrhagic complications. Additional risk factors for bleeding should be considered in these patients.