Epidemiology of ventilator-associated tracheobronchitis and ventilator-associated pneumonia caused by multidrug-resistant Gram-negative bacteria at a tertiary care hospital in Thailand

Abstract

Objectives: To investigate the epidemiology of MDR Gram-negative bacilli ventilator-associated tracheobronchitis (MDR GNB-VAT) and MDR GNB ventilator-associated pneumonia (MDR GNB-VAP) among mechanically ventilated patients. Methods: We conducted a retrospective observational study among hospitalized patients who underwent continuous mechanical ventilation for ≥48h at Siriraj Hospital, Thailand. Results: During the 18month study period, 1824 unique patients underwent continuous mechanical ventilation (12216ventilator-days). The cumulative incidences of MDR GNB-VAT and -VAP were 8.4% and 8.3%, respectively. The incidence rates of MDR GNB-VAT and -VAP were 12.52 and 12.44 episodes/1000ventilator-days, respectively. Among those with VAT, the cumulative incidence and incidence rate of subsequent VAP development within 7days were 11.76% and 2.81episodes/1000ventilator-days, respectively. The median durations of mechanical ventilation before having VAP and VAT were 9 and 12days, respectively. Multivariate analysis identified three independently associated factors for patients having VAP compared with having VAT: underlying cerebrovascular disease [adjusted OR (aOR): 0.46; 95% CI: 0.27-0.78; P=0.04], previous surgery (aOR: 0.68; 95% CI: 0.57-0.8; P<0.001) and acute renal failure (aOR: 1.75; 95% CI: 1.27-2.40; P=0.001). Conclusions: The study revealed high incidences of MDR GNB-VAT and -VAP among mechanically ventilated patients. The independent risk factors for having VAP can help identify patients at risk for developing VAP and who need early weaning from mechanical ventilation.