Predictors associated with mortality of veno-venous extracorporeal membrane oxygenation therapy

BACKGROUND: The use of veno-venous extracorporeal membrane oxygenation (V-V ECMO) has rapidly increased in recent years. Today, applications of V-V ECMO include a variety of clinical conditions such as acute respiratory distress syndrome (ARDS), bridge to lung transplantation and primary graft dysfunction after lung transplantation. The purpose of the present study was to investigate in-hospital mortality of adult patients undergoing V-V ECMO therapy and to determine independent predictors associated with mortality. METHODS: This retrospective study was conducted at the University Hospital Zurich, a designated ECMO center in Switzerland. Data was analyzed of all adult V-V ECMO cases from 2007 to 2019. RESULTS: In total, 221 patients required V-V ECMO support (median age 50 years, 38.9% female). In-hospital mortality was 37.6% and did not statistically vary significantly between indications (P=0.61): 25.0% (1/4) for primary graft dysfunction after lung transplantation, 29.4% (5/17) for bridge to lung transplantation, 36.2% (50/138) for ARDS and 43.5% (27/62) for other pulmonary disease indications. Cubic spline interpolation showed no effect of time on mortality over the study period of 13 years. Multiple logistic regression modelling identified significant predictor variables associated with mortality: age [odds ratio (OR), 1.05; 95% confidence interval (CI): 1.02–1.07; P=0.001], newly detected liver failure (OR, 4.83; 95% CI: 1.27–20.3; P=0.02), red blood cell transfusion (OR, 1.91; 95% CI: 1.39–2.74; P<0.001) and platelet concentrate transfusion (OR, 1.93; 95% CI: 1.28–3.15; P=0.004). CONCLUSIONS: In-hospital mortality of patients receiving V-V ECMO therapy remains relatively high. Patients’ outcomes have not improved significantly in the observed period. We identified age, newly detected liver failure, red blood cell transfusion and platelet concentrate transfusion as independent predictors associated with in-hospital mortality. Incorporating such mortality predictors into decision making with regards to V-V ECMO use may increase its effectiveness and safety and may translate into better outcomes.