Impact of Center of Admission on Receipt of Extracorporeal Membrane Oxygenation Among Patients With Hypoxemic Respiratory Failure: A Secondary Analysis of the Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure and Reseau Europeen de Recherche en Ventilation Artificielle Influenza A(H1N1) Studies

Abstract

BackgroundGiven the resources and specialized training required to deliver extracorporeal membrane oxygenation (ECMO), the provision of ECMO is often centralized within expert centres. Spurred by recent evidence the use of ECMO has increased dramatically. However, given the centralized nature of ECMO it is possible that inequities in access exist. Research QuestionDoes centre of admission impact the likelihood of receiving ECMO among adults with moderate or severe acute hypoxemic respiratory failure (PaO2/FiO2 ratio ≤ 200mmHg within 48hrs of ventilation). Study Design and MethodsWe performed a retrospective cohort study using data from the LUNG SAFE and REVA influenza A (H1N1) databases. Using modified log-Poisson analysis we estimated the likelihood of receiving ECMO (initiation at the admitting hospital or transfer for initiation), adjusting for disease severity over time. To explore unmeasured confounding, we evaluated the association between centre of admission on three negative controls: neuromuscular blockade, prone positioning, and dialysis. ResultsAmong 1,581 patients (37.7% female, mean age 60.7 years), 76 (4.8%) received ECMO. Longitudinal analysis, adjusted for trends in disease severity, demonstrated that patients admitted to ECMO centres were two-times more likely to receive ECMO than those admitted to non-ECMO centres (RR 2.00; 95% CI 1.17-3.41). Patients at ECMO centres received ECMO two days earlier than those at non-ECMO centres, median (IQR) time to initiation 1 (1-5) vs 3 (2-5) days (p=0.04). Centre of admission was not associated with neuromuscular blockade (RR 1.08; 95% CI 0.90-1.30), prone positioning (RR 0.93; 95% CI 0.68-1.28), or dialysis (RR 1.04; 95% CI 0.84-1.27). InterpretationAdults with hypoxemic respiratory failure admitted to ECMO centres were twice as likely to receive ECMO as those admitted to non-ECMO centres. These finding raise concerns regarding equity in access to care and suggest a potential lower threshold among clinicians at ECMO centres to initiate ECMO.