Design: Systematic review and meta-analysis of nine randomised trials
Population: 585 adults with or at risk of ARDS
Primary outcome: Mortality
Effect: RR 0.95 (95% CI 0.72–1.26); PaO₂/FiO₂ +56 mmHg (24.6–87.8)

A meta-analysis of nine randomised trials (585 adults with or at risk of ARDS) compared airway pressure release ventilation (APRV) with conventional ventilation.

Mortality did not differ (RR 0.95, 95% CI 0.72–1.26), and neither did ventilator-free days or ventilation duration. APRV raised the PaO₂/FiO₂ ratio by about 56 mmHg and shortened ICU stay by about 2.5 days, but with high heterogeneity (I² 71–84%) and low to very low certainty.

Better oxygenation without better survival is a familiar pattern in ARDS. The trials were small and protocols varied widely, so these data do not show APRV to be equivalent or superior to lung-protective conventional ventilation.

APRV did not reduce mortality compared with conventional ventilation
Improved oxygenation on APRV did not translate into survival
Lung-protective conventional ventilation remains the standard
Treat APRV as a rescue option in experienced hands, not a default

Why it matters

Chasing oxygenation numbers is not the same as improving outcomes.

The statistics, in plain English

A risk ratio of 0.95 with an interval from 0.72 to 1.26 means the trials are compatible with APRV being somewhat better or somewhat worse; no difference is shown.