Ventilator-associated pneumonia in an ICU: epidemiology, etiology and comparision of two bronchoscopic methods for microbiological specimen sampling

Introduction

Ventilator-associated pneumonia (VAP) is the most important ICU-acquired infection in mechanically ventilated patients that appears 48–72 hours after the beginning of mechanical ventilation. The aim of this study was to evaluate the incidence and microbiology of VAP and to compare two quantitative bronchoscopic methods – bronchoalveolar lavage (BAL) and bronchoscopic tracheobronchical secretion (TBS) – for the diagnosis.

Methods

The epidemiological and microbiological etiology of VAP in a surgical ICU with 65 patients during a 1-year period was evaluated in this prospective open, clinical study. The patients were divided into two groups: group I, 30 patients with mechanical ventilation longer than 48 hours with VAP (the case groups); group II, 35 patients with mechanical ventilation longer than 48 hours without VAP (the control group). Two types of quantitative bronchoscopic methods for identifying the etiological agent were compared (BAL and TBS).

Results

Among 65 long-term ventilated patients, 35 developed VAP (one more VAPs). VAP was caused predominantly by MRSA (35%), Pseudomonas aeruginosa (28%), Klebsiella sp. (14%), and Acinetobacter sp (14%). The treatment of patients with VAP who were ventilated for a longer period in the ICU took longer compared with patients without VAP. In our study, we did not find an increased mortality rate in patients undergoing long-term ventilation who acquired VAP compared with patients undergoing long-term ventilation without VAP.

Conclusion

The study showed that quantitative analysis for identifying bacterial etiology of VAP with one of two accessible bronchoscopic methods (BAL and TBS) produced identical results.