Personalized positive end-expiratory pressure in spontaneously breathing patients with acute respiratory distress syndrome by simultaneous electrical impedance tomography and transpulmonary pressure monitoring: a randomized crossover trial.

Abstract

Personalized positive end-expiratory pressure (PEEP) might foster lung and diaphragm protection in patients with acute respiratory distress syndrome (ARDS) who are undergoing pressure support ventilation (PSV). We aimed to compare the physiologic effects of personalized PEEP set according to synchronized electrical impedance tomography (EIT) and driving transpulmonary pressure (∆PL) monitoring against a classical lower PEEP/FiO₂ table in intubated ARDS patients undergoing PSV. A cross-over randomized multicenter study was conducted in 30 ARDS patients with simultaneous recording of the airway, esophageal and transpulmonary pressure, together with EIT during PSV. Following a decremental PEEP trial (18 cmH₂O to 4 cmH₂O), PEEP_EIT-∆PL was identified as the level with the smallest difference between lung overdistension and collapse. A low PEEP/FiO₂ table was used to select PEEP_TABLE. Each PEEP strategy was applied for 20 min, and physiologic data were collected at the end of each step. The PEEP trial was well tolerated. Median PEEP_EIT-∆PL was higher than PEEP_TABLE (10 [8-12] vs. 8 [5-10] cmH₂O; P = 0.021) and, at the individual patient level, PEEP_EIT-∆PL level differed from PEEP_TABLE in all patients. Overall, PEEP_EIT-∆PL was associated with lower dynamic ∆PL (P < 0.001) and pressure-time product (P < 0.001), but there was variability among patients. PEEP_EIT-∆PL also decreased respiratory drive and effort (P < 0.001), improved regional lung mechanics (P < 0.05) and reversed lung collapse (P = 0.007) without increasing overdistension (P = 0.695). Personalized PEEP selected using synchronized EIT and transpulmonary pressure monitoring could be associated with reduced dynamic lung stress and metabolic work of breathing in ARDS patients undergoing PSV.