Pathogens causing ventilator associated pneumonia and their antibiogram in a Tertiary Care Hospital in North Karnataka

Abstract

Background: Ventilator associated pneumonia (VAP) is the most frequent intensive care unit acquired infection and is one of the leading causes of morbidity and mortality in ICUs. Objectives: To isolate and identify the causative organisms of ventilator associated pneumonia with their antibiotic susceptibility patterns in ICU patients of tertiary care hospital in North Karnataka. Methods: A prospective cohort study was conducted over one year period in ICUs of a tertiary care hospital in North Karnataka. ICU patients who were intubated and on mechanical ventilation for more than 48 hours, in whom VAP was clinically suspected {Clinical Pulmonary Infection Score (CPIS) > 6} were included in this study. Endotracheal aspirates and endotracheal tube tips after extubation were collected as samples. Quantitative culture threshold of more than 105cfu/ml was considered as diagnostic of VAP. Fifty one isolates were obtained from 47 samples as mixed growth was seen from 4 samples. Results: The incidence of VAP in our study was 47.00%. The most common isolates were Pseudomonas aeruginosa (31.38%), Staphylococcus aureus (27.46%), Acinetobacter (11.76%) and Escherichia coli (11.76%). Most of the gram negative bacteria isolated were sensitive to Imipenem and Cefoperazone - sulbactum and gram positive bacteria were sensitive to Vancomycin. Conclusion: The sensitivity patterns of gram negative bacteria and gram positive bacteria vary according to the ICU and the population studied. The recovery rate (78.94%) was higher in the early onset VAP cases. Late onset VAP had higher mortality (64.28%) when compared to the early onset VAP group (21.05%).