Pao 2 and Mortality in Neonatal Extracorporeal Membrane Oxygenation: Retrospective Analysis of the Extracorporeal Life Support Organization Registry, 2015–2020

OBJECTIVES: Extracorporeal life support can lead to rapid reversal of hypoxemia but the benefits and harms of different oxygenation targets in severely ill patients are unclear. Our primary objective was to investigate the association between the Pa o 2 after extracorporeal membrane oxygenation (ECMO) initiation and mortality in neonates treated for respiratory failure. DESIGN: Retrospective analysis of the Extracorporeal Life Support Organization (ELSO) Registry data, 2015–2020. PATIENTS: Newborns supported by ECMO for respiratory indication were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Pa o 2 24 hours after ECMO initiation (H24 Pa o 2 ) was reported. The primary outcome was 28-day mortality. We identified 3533 newborns (median age 1 d interquartile range (IQR), 1–3; median weight 3.2 kg IQR, 2.8–3.6) from 198 ELSO centers, who were placed on ECMO. By 28 days of life, 731 (20.7%) had died. The median H24 Pa o 2 was 85 mm Hg (IQR, 60–142). We found that both hypoxia (Pa o 2 < 60 mm Hg) and moderate hyperoxia (Pa o 2 201–300 mm Hg) were associated with greater adjusted odds ratio (aOR 95% CI) of 28-day mortality, respectively: aOR 1.44 (95% CI, 1.08–1.93), p = 0.016, and aOR 1.49 (95% CI, 1.01–2.19), p value equals to 0.045. CONCLUSIONS: Early hypoxia or moderate hyperoxia after ECMO initiation are each associated with greater odds of 28-day mortality among neonates requiring ECMO for respiratory failure.