Incidence, bacteriological profile, and antibiotic susceptibility pattern of ventilator-associated pneumonia cases in critical care units of a tertiary care hospital

Abstract: Background: Ventilator-associated pneumonia (VAP) is a major healthcare-associated infection in critically ill patients on mechanical ventilation, contributing to increased morbidity, mortality, prolonged hospitalization, and antimicrobial resistance. Continuous surveillance of pathogens and their susceptibility patterns is essential for guiding empirical therapy and infection control. Objectives: The objective of this study was to determine the incidence, bacteriological profile, antibiotic sensitivity, and patient outcomes of VAP, and compare VAP with non-VAP patients in a tertiary care intensive care unit (ICU). Materials and Methods: This prospective observational cohort study was conducted over 10 months among patients aged 15–75 years requiring mechanical ventilation for more than 48 h. A total of 310 patients were included in the study. Endotracheal aspirates and tube tips were analyzed using standard microbiological methods, and antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method following Clinical and Laboratory Standards Institute guidelines. VAP diagnosis was based on the Clinical Pulmonary Infection Scoring System. Results: The incidence of VAP was 12.3%, with late-onset cases predominating (60.5%). Older age (>55 years) was significantly associated with VAP onset ( P = 0.015). Gram-negative organisms predominated, with Acinetobacter baumannii (29.0%), Pseudomonas aeruginosa (26.4%), and Klebsiella pneumoniae (23.6%) being most common. VAP patients had higher mortality (34.2% vs. 18.0%, P = 0.028), longer ICU stay (14.6 ± 5.2 vs. 9.3 ± 3.8 days, P < 0.001), and prolonged ventilation (11.2 ± 4.6 vs. 6.7 ± 3.1 days, P < 0.001). Conclusion: VAP showed a moderate incidence with predominance of multidrug-resistant Gram-negative organisms and was associated with worse clinical outcomes, highlighting the need for surveillance and appropriate antibiotic therapy.