To evaluate the effect of comprehensive airway intervention strategies on prognosis in mechanically ventilated patients and to analyze the mediating roles of pulmonary ventilation function and airway microbiota.

A total of 199 mechanically ventilated patients admitted to our hospital from August 2022 to December 2025 were enrolled and randomly divided into an observation group (n=102) and a control group (n=97). The control group received routine airway management, while the observation group received additional comprehensive airway interventions, including dynamic airway assessment, individualized humidification, precise sputum suction, artificial airway maintenance, and airway clearance. Pulmonary dynamic compliance (Cdyn), airway resistance (Raw), oxygenation index (PaO₂/FiO₂), airway microbiota diversity (Chao1 index, Shannon index), and clinical outcomes were compared between the two groups before and after treatment. Pearson correlation analysis, multiple linear hierarchical regression, and PROCESS macro model 4 were used for mediation analysis.

After treatment, the observation group showed significantly higher Cdyn [(58.62±9.47) ml/cmH₂O vs. (48.35±8.66) ml/cmH₂O, t=7.869, P<0.001] and PaO₂/FiO₂[(289.62±41.53) mmHg vs. (231.47±36.82) mmHg, t=9.905, P<0.001], and lower Raw [(12.15±3.12) cmH₂O/(L·s) vs. (15.36±3.57) cmH₂O/(L·s), t=-6.772, P<0.001] compared with the control group. The Chao1 index [(689.25±72.36) vs. (542.16±65.82), t=14.869, P<0.001] and Shannon index [(5.86±0.72) vs. (4.23±0.65), t=16.392, P<0.001] were also significantly higher in the observation group. The observation group had shorter duration of mechanical ventilation [(7.82±2.15) d vs. (11.36±3.42) d, t=-8.976, P<0.001], shorter ICU stay[(10.15±3.26) d vs. (14.72±4.15) d, t=-8.403, P<0.001], and lower mortality (10.78% vs. 24.74%, χ²=6.189, P=0.013) than the control group. Hierarchical regression showed that the final model had an R² of 0.685, and airway intervention strategy, Cdyn, PaO₂/FiO₂, and Shannon index were independent influencing factors for mechanical ventilation duration. Mediation analysis revealed that the mediating effect of pulmonary ventilation function and airway microbiota was -0.315 (95%CI: -0.390 to -0.249), accounting for 47.37% of the total effect.

Comprehensive airway intervention strategies can effectively improve pulmonary ventilation function and airway microbiota homeostasis, shorten mechanical ventilation duration and ICU stay, and reduce mortality in mechanically ventilated patients.