RESUMO
Objectives: It is well known that severe COVID-19 is associated with complex immunological and inflammatory dysregulation. Both these physiopathological events translate to a high risk of major thrombotic or hemorrhagic events. In patients treated with venovenous extracorporeal membrane oxygenation (VVECMO), membrane dysfunction might affect systemic oxygenation and limit its duration-expectancy. This study aimed to assess the possible causes of extracorporeal membrane failure in COVID-19 patients and its impact on outcome. Method(s): Retrospective, single-center, observational case-control study involving adult COVID-19 patients admitted to an ECMO referral centre in a tertiary university hospital. All patients required VVECMO for acute respiratory failure, including 48 cases who needed one or more extracorporeal membrane exchanges and 45 controls (no membrane exchange). These two groups were compared for demographic characteristics, severity of the disease using validated scores (SAPS II and SOFA), duration of ECMO run, coagulation assessment, cumulative anticoagulation dose, associated complications, and outcomes (ICU and hospital mortality). Result(s): Most patients were males (71.0%) and younger than 50 years (79.5%). Median ECMO run duration was significantly longer in the case group (35.0 vs 14.0 days, p <0.001), as well as ICU length-of-stay (45.5 vs 28 days, p <0.001). Membrane exchange tended to be associated with sepsis (56% vs 33%, p=0.037), major hemorrhage (58% vs 43%, p=0.022), heparin-induced thrombocytopenia (25% vs 9%, p=0.054), higher D-dimer title (17.36 ng/dL vs 7.5 ng/dL, p=0.07) and lower platelet counts (133.000/muL vs 154.000/muL). Median SAPS II (32.0 vs 33.0, p=0.20) and the mortality (27% vs 24%, p >0.99) were similar between these groups. Conclusion(s): In patients with SARS-CoV-2 pneumonia and severe hypoxemia treated with VVECMO support the emergence of infection, coagulopathy and inflammation were associated with high risk of membrane dysfunction. No impact on mortality could be confirmed from these data. Anticoagulation monitoring and dosing strategies should be reinforced to promote membrane protection.