Nursing interventions and multidomain physiological trajectories in ARDS: a retrospective cohort study.

Background: Nursing interventions play a key role in managing acute respiratory distress syndrome (ARDS), but their relationship with the dynamic physiological changes that occur during treatment is not well described. Methods: In a retrospective cohort of 1,716 ARDS patients from the West China Hospital Big Data Platform (2012-2025), four nursing interventions, airway suctioning, oral care, prone positioning, and early enteral nutrition were examined. Trajectories of SpO₂, C-reactive protein (CRP), lactate, and creatinine were derived using latent-class mixed-effects models. Associations between interventions and trajectory membership were assessed through multinomial logistic regression. Results: Three distinct trajectories were identified for each biomarker including oxygenation, inflammation, metabolism, and renal function. Early prone positioning initiated within 24 h was associated with lower odds of unfavorable oxygenation trajectories (SpO₂ trajectory 2: OR 0.08, 95% CI 0.01-0.59) and high-CRP trajectories (OR 0.18, 95% CI 0.04-0.86). Delayed prone positioning (>72 h) was associated with higher odds of both the stable-low lactate trajectory (trajectory 2: OR 5.17, 95% CI 1.21-22.06) and the U-shaped lactate trajectory (trajectory 3: OR 5.07, 95% CI 1.09-23.57). EEN was consistently linked to reduced odds of high-CRP trajectories (OR 0.31-0.45 across models). Airway suctioning was linked to more favorable oxygenation trajectories, while oral care was more common among patients with unstable oxygenation. Patients in unstable oxygenation trajectories had higher 28-day mortality, while the stable lactate trajectory showed a protective association. Conclusion: Distinct physiological trajectories characterize the early course of ARDS. Early and standardized nursing interventions, particularly prone positioning and enteral nutrition, were associated with more favorable recovery profiles.