RESUMEN
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. Aim(s): 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. Method(s): 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. Result(s): 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. (Table Presented).
RESUMEN
Thrombocytopenia is a common complication of COVID-19 (coronavirus disease 2019). The possible mechanisms include decreased platelet production, increased platelet destruction and consumption. According to studies, thrombocytopenia indicates a poor prognosis and increased mortality in COVID-19 patients. Meanwhile, thrombocytopenia is often complicated in extracorporeal membrane oxygenation (ECMO) due to shearing force in the circuit and heparin-induced thrombocytopenia (HIT). COVID-19 patients who are managed on ECMO are at high risk of developing thrombocytopenia and life-threatening bleeding. Venous thromboembolism (VTE) prevention is critical in managing COVID-19 patients. The balance between bleeding secondary to thrombocytopenia and thromboembolic prophylaxis is challenging. ECMO support also increases the risk of thrombocytopenia. Our retrospective observation study reports the incidences of thrombocytopenia and major bleeding events in 17 COVID-19 patients who were managed with ECMO. We retrospectively reviewed the data of 23 patients who were diagnosed with COVID-19 and managed on ECMO. Thrombocytopenia is defined by platelet level lower than 150 000/ul. Incidences of thrombocytopenia and related complications were recorded and analysed. Twenty-three adult patients who were diagnosed with COVID-19 received ECMO support. The mean age of patients was 45-year-old and mean body mass index (BMI) was 31.29. Seventeen patients were males, and 11 patients had at least one of the following pre-ECMO comorbidity: 10 (43.5%) patients had hypertension, 11 (47.8%) patients had type 2 diabetes and four (17.3%) patients had hyperlipidaemia. None of the patients were active smokers or had chronic lung disease when admitted. Anticoagulation was initiated on the day of admission. Twenty-one (91.3%) patients developed thrombocytopenia and HIT was excluded. Eighteen (78.3%) patients had haemorrhage requiring transfusion, with the gastrointestinal tract being the most common site. Other bleeding sites included brain, chest, tracheostomy area and cannulation site. Thromboembolic prophylaxis was held for active bleeding or platelet count threshold of <30 000/ul. Based on our data, the incidence of thrombocytopenia was 91.3% in ECMO-managed COVID-19 patients;78.3% patients developed haemorrhage requiring transfusion. Given the high risk of thromboembolic events in COVID-19 patients, anticoagulation is recommended to all hospitalized COVID-19 patients unless there is active bleeding, previous bleeding history within 3 days or platelet count is lower than 30 000 cells/ul. However, anticoagulation further increases the risk of bleeding in the setting of thrombocytopenia, which may lead to sudden deterioration and death. Further investigation into the mechanisms, implications and management of thrombocytopenia will lead to significantly improved outcomes and prognosis for COVID-19 patients who are managed on ECMO..
RESUMEN
Venous thromboembolism (VTE) is a common complication of COVID-19 (coronavirus disease 2019), which often leads to sudden deterioration and death. There are multiple mechanisms contributing to this phenomenon. Endothelial injury from COVID-19 triggers platelet activation and adhesion, leucocyte aggregation, cytokine storm and complement activation. Cytokine storm triggers coagulation activation and thrombin generation. Complement activation is also thought to trigger the formation of systemic thrombus through recruiting inflammatory cytokines and possible complement-mediated thrombotic microangiopathy. Patients on extracorporeal membrane oxygenation (ECMO) are at risk of developing thromboembolism. Thrombus formation within the extracorporeal circuit is the main reason for systemic thromboembolism. Possibly that by contacting blood and nonendothelial surfaces, ECMO triggers activation of coagulation pathway and inflammatory response. Thromboembolic prophylaxis is critical in managing COVID-19 patients on ECMO. Anticoagulation is recommended to all hospitalised COVID-19 patients unless there are contraindications. However, patients are still found to develop VTE while on anticoagulation and the prevalence of VTE in COVID-19 patients on ECMO is still unclear. We aim to investigate the VTE incidence and contribute to anticoagulation strategy and management in this specific population. We retrospectively reviewed the data of 23 patients who were diagnosed with COVID-19 and managed with ECMO. All patients received thromboembolic prophylaxis since admission. We report our findings of the incidences of thromboembolism. Twenty-three adult patients who were diagnosed with COVID-19 received ECMO support. Sixteen patients were minorities, and seven patients were Caucasians. The mean age of patients was 44.8-year old. Seventeen patients were males, and 11 patients had at least one of the following pre-ECMO comorbidity: ten (43.5%) patients had hypertension, 11 (47.8%) patients had type 2 diabetes and four (17.3%) patients had hyperlipidaemia. None of the patients were active smokers or had chronic lung disease. During the hospital course, all patients received heparin for thromboembolic prophylaxis. The overall VTE rate was 34.7%. Six patients developed deep vein thrombosis (DVT) (26%) with lower extremities induration. Two patients were found to have pulmonary embolism (PE) (8.7%). Four patients had clotted circuit that requiring exchange. No stroke or myocardial infarction (MI) was diagnosed in these patients. Heparin-induced thrombocytopenia (HIT) was excluded in all cases. Based on our study, the overall VTE rate of COVID-19 patients on ECMO was 34.7% with 26% incidence of DVT and 8.7% incidence of PE. According to Jenner's recent systemic review of 28 studies, 34% of 2928 ICU-managed COVID-19 patients developed VTE. PE was found in 12.6% of patients and DVT was detected in 16.1% of patients. 529 patients (18.0%) received ECMO in the cohort. When compared with our study, there were no statistically significant differences of the incidences of VTE, DVT or PE between these two studies, although all our patients were on ECMO support. Further investigation into the prevalence, implications and management of thromboembolism in COVID-19 patients on ECMO will lead to significantly improved outcomes for this specific patient population..