Background: Ventilator-associated pneumonia (VAP) is a major cause of morbidity and mortality in critically ill patients requiring mechanical ventilation. The increasing burden of multidrug-resistant (MDR) organisms has complicated treatment and outcomes. This study aimed to determine the bacteriological profile, antimicrobial resistance patterns, and clinical outcomes in patients with VAP in a tertiary-care intensive care unit (ICU) in Eastern India. Methods: This prospective observational study (February 2020–January 2022) included adults undergoing invasive mechanical ventilation for >48 hours who developed clinical suspicion of VAP , defined as new or progressive radiographic infiltrates plus ≥2 clinical features (fever/hypothermia, leukocytosis/leukopenia, purulent secretions, or worsening oxygenation). VAP was microbiologically confirmed by quantitative endotracheal aspirate culture ≥10 5 CFU/mL. Bacterial identification used standard biochemical methods, and antimicrobial susceptibility testing followed CLSI 2023 guidelines. Colistin minimum inhibitory concentrations were determined by broth microdilution. MDR was defined as nonsusceptibility to ≥1 agent in ≥3 antimicrobial classes. Results: Of 200 clinically suspected VAP cases, 76 (38%) were microbiologically confirmed. Early-onset VAP constituted 38.15% and late-onset VAP 61.85%. A total of 100 isolates were recovered; 91% were gram-negative bacilli, predominantly Klebsiella spp. (36%), Acinetobacter spp. (25%), and Pseudomonas spp. (24%). Over 90% of gram-negative isolates were resistant to third-generation cephalosporins and fluoroquinolones. Colistin resistance was identified in 5.49% of isolates. MDR prevalence was 73% overall, and was highest in late-onset VAP (76.5%). Mortality among culture-confirmed VAP patients was 48.68%. Conclusion: MDR gram-negative organisms remain the predominant etiological agents of VAP in this ICU setting, with emerging colistin resistance posing additional therapeutic challenges. These findings reinforce the need for ongoing surveillance, local antibiograms, and strengthened antimicrobial stewardship to optimize therapy and improve clinical outcomes.
Mahanta et al. (Thu,) studied this question.