VPB0124 - Thrombocytopenia in COVID-19 patients on ECMO

Background: Thrombocytopenia is a common complication of COVID-19 (coronavirus disease 2019). The possible mechanisms include decreased platelet production, increased platelet destruction, and consumption. Thrombocytopenia indicates a poor prognosis in COVID-19 patients. Thrombocytopenia is often complicated in ECMO (extracorporeal membrane oxygenation) due to shearing force in the circuit and heparin-induced thrombocytopenia (HIT). COVID-19 patients on ECMO are at high risk of developing thrombocytopenia and bleeding.

Aims: The balance between bleeding prevention secondary to thrombocytopenia and thromboembolic prophylaxis is challenging in managing COVID-19 patients. ECMO increases the risk of thrombocytopenia. Our study reports the incidences of thrombocytopenia and bleeding in COVID-19 patients on ECMO.

Methods: We retrospectively reviewed the data of twenty-three COVID-19 patients on ECMO. Thrombocytopenia is defined by platelet levels lower than 150,000/uL. Incidences of thrombocytopenia and complications were recorded and analyzed.

Results: Twenty-three COVID-19 patients received ECMO. The mean age was 45-year-old. Eleven patients had at least one of the following pre-ECMO comorbidity: ten patients had hypertension, eleven patients had diabetes and four patients had hyperlipidemia. None of the patients were active smokers or had chronic lung disease. Anticoagulation was initiated on the day of admission.
Twenty-one patients developed thrombocytopenia and HIT was excluded. Eighteen patients had hemorrhage requiring transfusion, with the gastrointestinal tract being the most common site. Thromboembolic prophylaxis was held for active bleeding or platelet count below 30,000/uL. The overall mortality rate was 69.6%.

Conclusion(s): In our study of ECMO-managed COVID-19 patients, 91.3% of patients developed thrombocytopenia and 78.3% of patients developed hemorrhage requiring transfusion. Anticoagulation is recommended to all hospitalized COVID-19 patients unless there are contraindications due to the high risk of thromboembolism. However, anticoagulation further increases the risk of bleeding, which may lead to sudden deterioration and death. Further investigation into the mechanisms, implications, and management of thrombocytopenia will lead to significantly improved outcomes for COVID-19 patients on ECMO.