Electrical impedance tomography-guided PEEP and mortality of patients with the acute respiratory distress syndrome: The EITVent randomized clinical trial

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/FiO(2) 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/FiO(2) 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 7 days (difference in marginal means 0.2 [SE 0.1]; P = .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/FiO(2) table group (hazard ratio [HR] 0.96 [95% CI, 0.65-1.41]; P = .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 = .024). Conclusions: In patients with moderate to severe ARDS, EIT-guided PEEP did not significantly reduce 28-day mortality compared with the lower PEEP/FiO(2) table strategy. Due to early termination, the study may have been underpowered to detect a clinically important difference.