Trajectory-based analysis of early mechanical ventilation PEEP levels and physiological parameter trajectories in ARDS patients and their association with the occurrence of gastrointestinal injury events.

Background: Mechanical ventilation is crucial in the treatment of acute respiratory distress syndrome (ARDS), but is associated with complications, including gastrointestinal injury (GI). This study investigates the association between early mechanical ventilation parameter trajectories and the occurrence of GI events in ARDS patients.

Methods: A retrospective cohort study using the MIMIC-IV database employed group-based trajectory modeling (GBTM) to identify trajectory patterns during early mechanical ventilation in ARDS patients. Kaplan-Meier analysis estimated GI events incidence across trajectory groups, and Cox regression models assessed independent risk associations, adjusting for clinical confounders. We evaluated and compared the model in order to enhance its robustness.

Results: A total of 1,344 ARDS patients were included, with four trajectory groups identified. Patients in Group 1 (low PEEP, moderate VT, lower frequency spontaneous breathing) exhibited the highest GI risk, while Group 2 (high PEEP, low tidal volume, controlled spontaneous breathing) had the lowest risk (HR: 0.606, 95% CI: 0.418-0.879, P = 0.008). Kaplan-Meier curves revealed a consistent pattern with Group 1 showing the highest cumulative incidence of GI events. Aspirin use, heparin therapy, renal replacement therapy, and APACHE II score were identified as independent factors for GI events. Subgroup analysis did not show intergroup differences. Sensitivity analyses confirmed model robustness.

Conclusions: Ventilation parameter trajectories are associated with GI injury risk in ARDS patients. Strategies optimizing PEEP levels and spontaneous breathing may mitigate this risk, supporting the need for individualized ventilation approaches.