Prevalence, Risk Factors, and Mortality of Veno-Venous Extracorporeal Membrane Oxygenation Escalation in Acute Respiratory Distress Syndrome: A Multicenter Cohort Study From the Chinese Society of Extracorporeal Life Support Registry.

Abstract

Patients with acute respiratory distress syndrome (ARDS) undergoing venovenous extracorporeal membrane oxygenation (ECMO) may experience severe cardiogenic shock, necessitating ECMO mode "escalation" for cardiopulmonary co-support. There is a paucity of data regarding the prevalence, risk factors, and mortality of venovenous ECMO escalation. We aimed to conduct a large study to address this issue. A multicenter cohort study. The analysis was conducted based on data from the Chinese Society of Extracorporeal Life Support registry, a nationwide voluntary platform capturing clinical information of patients receiving ECMO support. Data were collected from 112 centers across China between January 2017 and December 2023. Eligible participants included adult patients with ARDS receiving venovenous ECMO, excluding pregnant patients and those with missing data on escalation. None. The primary outcome was in-hospital mortality. Of the 3333 patients on venovenous ECMO, 157 (4.7%) underwent escalation to venoarterial ECMO ( n = 41), veno-arterial-venous (VAV) ECMO ( n = 68), and veno-veno-arterial (VVA) ECMO ( n = 48). Several characteristics, including hospital's annual venovenous ECMO volume (hospitals > 15 cases per year vs. those < 6 cases per year; odds ratio [OR], 0.596; 95% CI, 0.382-0.930), were associated with the occurrence of escalation. The overall in-hospital mortality was 47.9%. Both escalation and lower hospital's venovenous ECMO volume were independently associated with an increased mortality. Compared with patients escalated to VVA ECMO, those escalated to venoarterial ECMO had a significantly higher survival rate (OR, 3.444; 95% CI, 1.046-11.342), whereas those escalated to VAV ECMO did not. In this study, 4.7% of ARDS patients with venovenous ECMO underwent a mode escalation. Escalation was independently associated with higher in-hospital mortality, an association that may be partially confounded by low hospital's venovenous ECMO volume. Among the modes after escalation, venoarterial ECMO was associated with a significantly higher survival rate. These findings require validation by further prospective multicenter studies to guide decision-making for ARDS patients requiring ECMO support.