Incidence of multidrug-resistant organisms causing ventilator-associated pneumonia in a tertiary care hospital: A nine months' prospective study

BACKGROUND: Ventilator-associated pneumonia (VAP) is an important intensive care unit (ICU) infection in mechanically ventilated patients. VAP occurs approximately in 9-27% of all intubated patients. Due to the increasing incidence of multidrug-resistant organisms in ICUs, early and correct diagnosis of VAP is an urgent challenge for an optimal antibiotic treatment. AIM OF THE STUDY: The aim of the study was to assess the incidence of VAP caused by multidrug-resistant organisms in the multidisciplinary intensive care unit (MICU) of our tertiary care 1,400-bedded hospital. MATERIALS AND METHODS: This prospective study was done in the period from December 2005 to August 2006, enrolling patients undergoing mechanical ventilation (MV) for >48 h. Endotracheal aspirates (ETA) were collected from patients with suspected VAP, and quantitative cultures were performed on all samples. VAP was diagnosed by the growth of pathogenic organism ≥10(5) cfu/ml. RESULTS: Incidence of VAP was found to be 45.4% among the mechanically ventilated patients, out of which 47.7% had early-onset (<5 days MV) VAP and 52.3% had late-onset (>5 days MV) VAP. Multiresistant bacteria, mainly Acinetobacter spp. (47.9%) and Pseudomonas aeruginosa (27%), were the most commonly isolated pathogens in both types of VAP. Most of the isolates of Escherichia coli (80%) and Klebsiella pneumoniae (100%) produced extended-spectrum beta lactamases (ESBLs). As many as 30.43% isolates of Acinetobacter spp. showed production of AmpC beta lactamases among all types of isolates. Metallo-beta lactamases (MBLs) were produced by 50% of Pseudomonas aeruginosa and 21.74% of Acinetobacter spp. CONCLUSION: High incidence (45.4%) of VAP and the potential multidrug-resistant organisms are the real threat in our MICU. This study highlighted high incidence of VAP in our setup, emphasizing injudicious use of antimicrobial therapy. Combined approaches of rotational antibiotic therapy and education programs might be beneficial to fight against these MDR pathogens and will also help to decrease the incidence of VAP.