Extracorporeal membrane oxygenation without invasive mechanical ventilation for acute respiratory distress syndrome: an international cohort study

RATIONALE: In acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) without invasive mechanical ventilation (IMV) is particularly challenging. OBJECTIVES: To study ARDS patients treated with ECMO to avoid IMV (primary awake ECMO) or with extubation during ECMO support (extubated ECMO). METHODS: International retrospective cohort of adult ARDS patients treated with ECMO without IMV at 14 centers in 8 countries (2015-2024). The primary outcome was mortality 90 days after ECMO initiation. MEASUREMENTS AND MAIN RESULTS: Among 307 adult patients with ARDS, 113 received primary awake ECMO, and 194 were extubated on ECMO. Ninety-day mortality was 30.1% in the primary awake ECMO group and 14.9% in the extubated ECMO. Strategy failure occurred in 46 (40.7%) patients and 47 (24.2%) patients, respectively, most frequently within the first 10 days. In multivariate analysis, strategy failure was associated with 90-day mortality (hazard ratio [HR] = 7.67; 95% CI, 3.44-17.11; P < .001 in extubated ECMO; HR = 5.95; 95% CI, 2.63-13.46; P < .001 in primary awake ECMO), while higher age and longer time from ICU admission to ECMO cannulation were associated with 90-day mortality in extubated ECMO and primary awake ECMO, respectively. The leading cause of strategy failure was worsening of respiratory failure, followed by agitation/delirium in primary awake ECMO and inability to clear secretions in extubated ECMO. CONCLUSIONS: Patients selected for primary awake ECMO and extubated ECMO presented different baseline characteristics, strategy failure, and 90-day mortality rates. However, strategy failure was consistently associated with 90-day mortality in both groups.