Abstract Rationale Physiological studies showed benefits for bedside setting of personalized positive end-expiratory pressure (PEEP) by electrical impedance tomography (EIT), balancing lung overdistension and collapse. Objectives To evaluate whether EIT-guided PEEP improves the clinical outcomes of patients with acute respiratory distress syndrome (ARDS) compared to the lower PEEP/FiO2 table strategy. Methods This randomized trial enrolled adult patients with moderate to severe ARDS across five sites in China from February 2022 to June 2023. Participants were randomly assigned to EIT-guided PEEP (collapse-overdistension crossing point value by decremental PEEP trial) or the classical lower PEEP/FiO2 table. The primary outcome was 28-day mortality. Measurements and Main Results The trial was terminated early for futility, based on a pre-planned interim analysis. A total of 190 patients were included and completed follow-up. PEEP levels didn’t differ between groups during the first seven days (difference in marginal means 0.2 standard error 0.1; p = 0.187). At 28 days, mortality was 52 patients (55.9%) in the EIT-guided PEEP group and 51 patients (52.6%) in the lower PEEP/FiO2 table group (hazard ratio HR 0.96 95% confidence interval (CI) 0.65-1.41; p = 0.821). Ventilator-free days and other secondary clinical and safety outcomes did not differ, either. However, EIT-guided PEEP assigned higher PEEP and decreased mortality in patients with higher lung recruitability, as assessed by the recruitment-inflation ratio method (16 35.6% of 45 patients vs. 27 60.0% of 45 patients; HR 0.49 95% CI 0.26-0.91; p = 0.024). Conclusions In patients with moderate to severe ARDS, EIT-guided PEEP did not significantly reduce 28-day mortality compared with the lower PEEP/FiO2 table strategy. Due to early termination, the study may have been underpowered to detect a clinically important difference. Trial registration clinicaltrials.gov NCT05207202
Yuan et al. (Mon,) studied this question.