ABSTRACT
Background: Use of venous-venous extracorporeal membrane oxygenation (VV-ECMO) increased significantly during the Coronavirus Disease 2019 (COVID-19) pandemic. COVID-19 has been associated with an immunothrombotic phenotype with increased pulmonary angiopathy, hypercoagulability and thrombosis (Patel et al., 2020). We evaluated whether the immunothrombotic phenotype of COVID-19 influenced membrane lung (ML) dysfunction in the Cardiohelp System (Getinge). Methods: Single centre retrospective cohort study comparing incidence and clinical indices prior to first circuit change (CC) for ML dysfunction, between consecutive COVID-19 and non-COVID-19 patients. Results: 210 adult patients (age≥16) treated with VV-ECMO between 20th Feb 2019 and 25th February 2021 with the Cardiohelp System were included. COVID-19 patients (N=96) had a greater incidence of CC compared to non-COVID-19 patients (N=114) (60% vs 37%, P<0.001) (Table 1). Despite no difference in mortality (17% vs 16%;P>0.05), COVID-19 patients who required CC had a significantly longer ECMO duration (19.52 vs 12.38 days;P<0.0001). Both groups had similar time to CC (11.71 vs 9.16 days;P>0.05). COVID-19 patients showed significantly greater increase in MO resistance prior to CC versus non-COVID-19 patients (ΔTransmembrane pressure/blood flow: 1.4 versus 0.7 mmHg/L/minute;P<0.0001). Changes from 5 days prior to day of CC that were different in COVID-19 compared to non-COVID-19 included D-dimer (1328 vs 15190ng/ml;P<0.0001) and fibrinogen (-0.99 vs -1.64g/L;P<0.0001). Conclusion: COVID-19 patients showed increased incidence of MO resistance despite changes in D-dimer and fibrinogen being less obvious compared to non-COVID-19 patients. This may reflect altered pathophysiology and increased immunothrombosis in COVID-19 patients which requires further investigation.