244: Ecmo Saves Lives at Experienced Centers: National Inpatient Sample Ards Study

Introduction: Extracorporeal membrane oxygenation (ECMO) utilization for acute respiratory distress syndrome (ARDS) remains controversial following equivocal trial results. Real-world effectiveness across diverse healthcare settings is unknown. We evaluated ECMO outcomes for ARDS using a nationally representative database, examining whether hospital ECMO volume modifies treatment effectiveness. Methods: We analyzed the National Inpatient Sample (2016-2022), identifying adult ARDS hospitalizations using validated ICD-10 codes. The primary outcome was in-hospital mortality. We employed propensity score matching, with >40 variables including demographics, comorbidities, organ failures, and hospital characteristics with interaction terms. Hospitals were stratified by annual ECMO volume (≥5 cases=high). Subgroup analyses examined ECMO type, cardiac arrest, and COVID-19 status. Economic outcomes included total charges and length of stay. Statistical analysis used survey-weighted regression for the NIS sampling design. Grammarly was used to edit the abstract. Results: Among 82,948 ARDS hospitalizations (representing 414,740 weighted cases nationally), 3,011 (3.6%) received ECMO. After propensity matching (2,980 ECMO patients matched), overall mortality was similar (ECMO 45.8% vs control 45.4%, p=0.78). However, hospital volume significantly modified the treatment effect. At high-volume centers (n=2,200), ECMO improved survival (OR 1.31, 95%CI 1.08-1.59, p=0.005), while at low-volume centers (n=3,329), ECMO worsened survival (OR 0.87, 95%CI 0.75-0.99, p=0.046). VA-ECMO showed higher mortality than VV-ECMO (OR 1.87, 95%CI 1.47-2.38). Cardiac arrest patients experienced worse outcomes with ECMO (interaction p< 0.001). ECMO increased costs by $700,908 per patient and length of stay by 11.2 days. COVID-19 diagnosis did not modify ECMO effectiveness (p=0.77). Conclusions: ECMO demonstrated no overall survival benefit for ARDS in this large real-world analysis, with substantial costs. Critical effect modification by hospital volume suggests ECMO improves survival only at experienced centers while potentially causing harm at low-volume hospitals. These findings support regionalizing ECMO services to high-volume centers and emphasize careful patient selection, particularly avoiding ECMO in cardiac arrest patients.