Bacteriology and antibiotic susceptibility pattern of ventilator-associated pneumonia in a tertiary care hospital

ABSTRACT

Background: Ventilator-associated pneumonia (VAP) is one of the most important hospital-acquired infections. VAP is pneumonia that develops 48 h or more after patients have been intubated and received mechanical ventilation by means of an endotracheal tube or tracheostomy. VAP is usually suspected when an individual develops a new or progressive infiltrates on chest radiograph, leukocytosis, and purulent tracheobronchial secretions. This is diagnosed based on positive end-expiratory pressure, fraction of inspired oxygen, bacteriological evidence, and signs of pulmonary infection. VAP is considered as one of the leading causes of morbidity and mortality in intensive care units (ICUs). Objectives: The objectives of this study were to assess the common pathogenic bacteria causing VAP and to determine its antibiotic susceptibility pattern. Materials and Methods: This study was conducted on 100 patients with clinical diagnosis of VAP. Bacterial culture was done for patient’s endotracheal aspirates. Antibiotic sensitivity test was done for culture-positive cases by Kirby–Bauer disk diffusion method. Results: A total of 72 patients (72%) showed positive culture. Gram-negative bacilli accounted for 91% of the isolated organisms with Acinetobacter species accounting for 40% followed by Pseudomonas species (26%) and Klebsiella pneumoniae (14%). Majority of the organisms were sensitive to imipenem with Acinetobacter being sensitive in 51% cases, Pseudomonas in 56%, and Klebsiella in 42% cases. Conclusion: Surveillance of VAP in ICUs is required to find out common causative organism and its antibiotic susceptibility to different antibiotics. This type of surveillance study is helpful for formulating antibiotic policy that would be more rational to reduce mortality and morbidity associated with VAP.