Outcomes of patients with initial acute respiratory failure on veno-venous extracorporeal membrane oxygenation (ECMO) requiring additional circulatory support by VVA-ECMO

Background: Veno-venous (VV) extracorporeal membrane oxygenation (ECMO) is increasingly used to support patients with severe acute respiratory distress syndrome (ARDS). In case of additional cardio-circulatory failure, some experienced centers upgrade the VV-ECMO with an additional arterial backflow cannula (termed VVA-ECMO). Here we analyzed short- and long-term outcome together with potential predictors of mortality. Methods: Retrospective analysis of outcome in VV ECMO patients with ARDS that received VVA upgrade due to acute cardio-circulatory deterioration from 2008-2021 at three ECMO referral centers.Results: We identified 73 VVA ECMO patients that either required an upgrade from VV to VVA (n=53) or were directly triple cannulated (n=20), most commonly for concomitant right-sided heart failure. Median (Interquartile Range) age was 49 (28-57) years and SOFA score was 14 (12-17) at VVA ECMO upgrade. ECMO support was required over 12 (6-22) days and ICU length of stay was 32 (16-46) days. Overall ICU mortality was 48% and hospital mortality 51%. Two additional patients died after hospital discharge while the remaining patients survived up to two years (with six patients being lost to follow-up). A SOFA score > 14 at the day of VVA upgrade and higher lactate level were independent predictors of mortality in the multivariate regression analysis.Conclusions: In this analysis, the use of VVA ECMO in patients with initial ARDS and concomitant cardiocirculatory failure was associated with a hospital survival of about 50%, and most of these patients survived up to 2 years. A SOFA score >14 and elevated lactate levels at the day of VVA upgrade predict unfavorable outcome.