Dynamic Parameters within the First 72 H of ICU Admission Predict Extubation Failure and 28‐Day Mortality in Severe Pneumonia‐Induced ARDS: A Retrospective Cohort Study

ABSTRACT Objective To evaluate dynamic parameter changes within 72 h of intensive care unit (ICU) admission for predicting extubation failure and 28‐day mortality in patients with severe pneumonia‐induced acute respiratory distress syndrome (ARDS). Methods This retrospective cohort study enrolled 424 adults with severe pneumonia‐induced ARDS receiving invasive ventilation ≥ 48 h during January 2023–August 2025. We collected clinical data and calculated 72‐h changes (Δ) in key parameters: physiological stress [maximum respiratory rate (RR), mean heart rate (HR)] and disease progression [ΔPaO 2 /FiO 2 , Δ blood lactate (BLA), Δ procalcitonin (PCT), Δ Sequential Organ Failure Assessment (SOFA)]. Outcomes were extubation failure (first spontaneous breathing trial failure or reintubation ≤ 48 h) and 28‐day mortality. Multivariable logistic and Cox regression models were built, with discrimination assessed by ROC curves. Results Extubation failure and 28‐day mortality rates were 23.82% (101/424) and 29.48% (125/424), respectively. For extubation failure, independent risk factors included older age, higher APACHE II score at admission, immunosuppression, higher maximum RR, higher mean HR, and increased ΔBLA, ΔPCT, and ΔSOFA (protective factor: increased ΔPaO 2 /FiO 2 ) ( p < 0.05). The prediction model had an AUC of 0.912 (95% CI, 0.883–0.941). For 28‐day mortality, independent risk factors were higher APACHE II score at admission, higher maximum RR, increased ΔBLA, and increased ΔSOFA ( p < 0.05), with a time‐dependent AUC of 0.755 (95% CI, 0.729–0.781). A significant association was observed between extubation failure and 28‐day mortality, with a markedly higher mortality rate in patients with extubation failure compared to those with successful extubation (81.19% vs. 13.31%, p < 0.001). Conclusion Dynamic parameters within 72 h of ICU admission are predictors of extubation failure and 28‐day mortality in severe pneumonia‐induced ARDS, offering a tool for early risk stratification. Extubation failure was also strongly associated with increased short‐term mortality, underscoring its clinical significance as an adverse outcome during the disease course.