Resistance patterns of the isolates of ventilator associated pneumonia and associated risk factors in a tertiary care hospital of Pakistan

Abstract

Background: Ventilator-associated pneumonia is a lifethreatening infection often caused by multi-drug resistant pathogens. The irrational use of broad-spectrum antibiotics has resulted into the increasing emergence of antimicrobial resistance among critically ill patients in the Intensive Care Units (ICUs). Methods & Materials: A prospective study was designed to determine the antimicrobial susceptibility patterns of pathogens isolated from ventilator-associated pneumonia (VAP), to evaluate the efficacy of antibiotics using agar disc diffusion method in a tertiary care hospital of Pakistan. For this purpose, a total of 380 morbid samples of endotracheal secretions were collected on the first day of the insertion of endotracheal tube and were primarily cultured for the evidence of any previous respiratory infection. Antibiotic susceptibility testing was determined for all positive cultures using the Kirby-Bauer disc-diffusion method. Results: A total of 380 morbid samples of endotracheal aspirates were analyzed which showed that 73% patients had acquired the ventilator-associated pneumonia. The most important risk factors responsible for the infection and antibiotic resistance in ventilated patients were elderly male patients, increasing duration of ventilator and severe underlying respiratory infections. All of the isolates including Staphylococci, Streptococci, Acinetobacter, Pseudomonas, Enterobacter, Klebsiella, Escherichia, and of Proteus, presented variable resistance (12-86%) against the tested antibiotics. Most of the isolates were found resistant (>42%) to Augmentin, Gentamycin, Cefazolin, Ceftriaxone, Doxycycline, Tetracycline, Clindamycin and Ciprofloxacin. The maximum antimicrobial activity was observed for Meropenem, Tobramycin, Fucidin, Linezolid, Vancomycin, Tigecycline and Tazocin. The sensitivity patterns of Tigecycline were found superior as compared to others. Conclusion: To ensure future potency of antibiotics and counteract resistance trend; rational antibiotic use and comprehensive surveillance of antibiotics resistance are very important especially with respect to hospital acquired infections.