Independent Determinants of Ventilator-Associated Pneumonia in Critically Ill Mechanically Ventilated Patients: A Prospective Multicenter Cohort Study

Abstract

Introduction: Ventilator-associated pneumonia (VAP) remains a major source of morbidity and mortality among critically ill patients requiring mechanical ventilation, contributing to prolonged intensive care unit (ICU) stays, increased healthcare costs, and worse clinical outcomes. Early identification of patients at high risk for VAP is essential for strengthening preventive strategies and optimizing critical care management.

Methods: We conducted a prospective multicenter cohort study involving adult patients who required invasive mechanical ventilation for > 48 h. Demographic, clinical, and ventilatory data were systematically collected from ICU admission until extubation or death. The primary outcome was VAP, which was defined according to standardized clinical and microbiological criteria. Multivariable logistic regression analysis was performed to identify the independent determinants of VAP after adjusting for clinically relevant confounders.

Results: Among 512 patients on mechanical ventilation, 126 (24.6%) developed VAP. The independent determinants of VAP included prolonged duration of mechanical ventilation, higher baseline severity scores, reintubation, supine positioning, and inadequate oral hygiene practices. In contrast, early initiation of enteral nutrition and strict adherence to ventilator care bundles were associated with a significantly lower risk of VAP development. The predictive model demonstrated good discrimination, thereby supporting its clinical utility.

Conclusion: VAP remains a frequent and clinically significant complication in patients on mechanical ventilation, driven by identifiable and potentially modifiable determinants. Early risk stratification based on these factors may enable targeted preventive interventions, reduce the burden of VAP, and improve outcomes in critically ill patients.