Francesco Mojoli, Diana Adrião, Marco Pozzi, Mariachiara Giacosa, Raquel Couto, Anita Orlando, Giuseppe Maggio, Ottavia Ferraro, Silvia Mongodi

Am J Respir Crit Care Med. 2026 Apr 1;212(4):827-829. doi: 10.1093/ajrccm/aamaf120.

• PMID: 41738091
• DOI: 10.1093/ajrccm/aamaf120
• Cite: Mojoli F, Adrião D, Pozzi M, Giacosa M, Couto R, Orlando A, Maggio G, Ferraro O, Mongodi S. Validation of thresholds for tidal lung hysteresis to detect tidal recruitment/derecruitment in patients with acute respiratory distress syndome. Am J Respir Crit Care Med. 2026 Apr 1;212(4):827-829. doi: 10.1093/ajrccm/aamaf120. PMID: 41738091.

“Extract from AJRCCM

To the Editor

During a decremental positive end-expiratory pressure (PEEP) ­trial, insufficient PEEP may lead to expiratory lung collapse followed by inspiratory reopening (tidal recruitment/derecruitment), an injurious mechanism that may misleadingly increase measured respiratory system compliance (Crs), ultimately resulting in setting a PEEP level that does not prevent alveolar instability.1-3 A combined assessment of Crs and tidal hysteresis improves interpretation of the trial, because tidal recruitment/derecruitment is indicated by a large increase in hysteresis following PEEP reduction.1,4 In a previous post hoc analysis among patients with COVID-19 acute respiratory distress syndrome (ARDS), an absolute hysteresis threshold (≥100 mL) predicted tidal recruitment/derecruitment without requiring comparison between different PEEP levels.1 We performed an external validation of this threshold to detect alveolar instability using a single assessment of hysteresis, independently of a PEEP trial. In addition, we sought to identify a cutoff for hysteresis normalized to the patient’s predicted body weight (PBW)….