Extracorporeal membrane oxygenation (ECMO) support for acute hypoxemic respiratory failure patients: outcomes and predictive factors

Abstract

Background: Extracorporeal membrane oxygenation (ECMO) is an important rescue therapy for patients with refractory respiratory or circulatory failure. High cost and associated complications warrant careful case selection. The aim of this study was to investigate the outcomes and factors associated with mortality in acute hypoxemic respiratory failure patients who received ECMO support, and to externally validate preexisting ECMO survival prediction scoring systems. Methods: This retrospective study enrolled acute hypoxemic respiratory failure patients who received veno-venous (VV) or veno-arterial (VA) ECMO support at Siriraj Hospital (Bangkok, Thailand) from 2010 to 2020. All relevant baseline patient characteristics including ECMO survival prediction scores were recorded. The primary outcome was in-hospital mortality. Multivariate logistic regression analysis was employed to identify independent predictors of in-hospital mortality. Results: Of a total of 65 patients, 34 (52%) were male, the median (IQR) age was 61 years (49–70 years), the median body mass index (BMI) was 22.6 kg/m2 (20.6–28 kg/m2), and the median Sequential Organ Failure Assessment (SOFA) score was 13 [11–16]. Forty-three patients (66%) received VV-ECMO, and 22 (34%) received VA-ECMO support. In-hospital mortality was 69%. Multivariate analysis identified a SOFA score >14, hospitalized >72 hours before ECMO initiation, PaO2/FiO2 ratio <60, and pH <7.2 as independent predictors of in-hospital mortality. These four parameters were combined to create the SHOP (S: SOFA >14, H: hospitalize >72 hours, O: PF ratio <60, and P: pH <7.2) score. Compared with three different preexisting ECMO survival prediction scoring systems, the SHOP score had the highest area under the curve (AUC) for predicting in-hospital mortality (overall: 0.873, VV-EMCO: 0.866, and VA-EMCO: 0.891). Conclusions: In-hospital mortality among ECMO-supported patients was high at 69%. SOFA score >14, hospitalized >72 hours, PaO2/FiO2 ratio <60, and pH <7.2 were found to be independent predictors of in-hospital mortality. A SHOP score of 2 or higher significantly predicts in-hospital mortality in EMCO-supported patients. Trial Registration: www.clinicaltrials.gov (reg. No. NCT 04031794).