Retrospective cohort study reveals increased 28-day mortality from early hyperoxia in postcardiotomy ECMO patients, highlighting the need for conservative oxygen targets.
Key Points
To evaluate the association between early arterial hyperoxia during the first 24 hours of support and 28-day all-cause mortality in adult postcardiotomy venoarterial ECMO patients.
Conducted a two-center retrospective cohort study of 209 adult postcardiotomy venoarterial ECMO patients treated between January 2019 and December 2024.
Measured 24-hour mean arterial oxygen partial pressure (24h-mean PaO2) as the primary exposure and analyzed its relationship with 28-day all-cause mortality using multivariable Cox proportional hazards models.
Overall 28-day mortality was 54.1%, with survival falling stepwise across increasing oxygen exposure from 64.1% in the <150 mm Hg group to 17.9% in the ≥300 mm Hg group (P < .001).
Each 10 mm Hg increase in 24h-mean PaO2 was associated with a 2.8% rise in mortality risk (adjusted HR 1.028, 95% CI: 1.011–1.046, P = .002), and severe hyperoxia (≥300 mm Hg) independently increased mortality (adjusted HR 2.392, 95% CI: 1.359–4.210).
A nonlinear dose-response relationship demonstrated an acceleration in mortality risk above approximately 200 mm Hg, with stronger adverse associations observed in older and male patients.