The impact of PEEP-guided electrical impedance tomography on oxygenation and respiratory mechanics in moderate-to-severe ARDS: a randomized controlled trial.

Electrical impedance tomography (EIT)-guided positive end-expiratory pressure (PEEP) titration may optimize ventilation and reduce ventilator-induced lung injury in acute respiratory distress syndrome (ARDS). We compared EIT-guided PEEP with low PEEP/FiO₂ strategy in patients with moderate-to-severe ARDS. In this randomized controlled trial, 108 patients with PaO₂/FiO₂ below 200 mmHg were allocated to EIT-guided PEEP after a recruitment maneuver (n = 56) or low PEEP/FiO₂ strategy (n = 52). Patients in the EIT group underwent PEEP titration guided by the intersection point between alveolar overdistension and collapse during a decremental PEEP trial. Primary outcomes were oxygenation (PaO₂/FiO₂) and static compliance. Secondary outcomes included mortality, ventilator-free days, ICU stay, barotrauma, rescue therapies, and sequential organ failure assessment (SOFA) score changes. On day 1, oxygenation was higher with EIT (mean PaO₂/FiO₂ 180 vs. 159 mmHg; p = 0.036). Static compliance was greater at both day 1 (26 vs. 23 mL/cmH₂O; p = 0.016) and day 2 (27 vs. 24 mL/cmH₂O; p = 0.029). Driving pressure was lower with EIT at day 1 (16 vs. 17 cmH₂O; p < 0.001) and day 2 (15 vs. 17 cmH₂O; p = 0.005). SOFA scores improved more in the EIT group (day 1: - 1 vs. 0, p = 0.013; day 2: - 1 vs. - 0.5, p = 0.015). Twenty-eight-day mortality was lower with EIT (29 vs. 44%), although not statistically significant (p = 0.090). ICU stay, ventilation duration, barotrauma, ECMO use, and rescue therapies were similar. Benefits were most pronounced in patients with severe ARDS. EIT-guided PEEP improved oxygenation, lung mechanics, and reduced organ dysfunction in moderate-to-severe ARDS, particularly in severe cases. It showed a trend toward reduced mortality and may serve as a practical bedside tool for lung-protective ventilation. Larger multicenter trials are needed to confirm its clinical benefits.Trial registration: ClinicalTrials, NCT06733168. Registered on 13/12/2024, https://clinicaltrials.gov/study/NCT06733168 .