Risk factors for tracheobronchial acquisition of resistant Gram-negative bacterial pathogens in mechanically ventilated ICU patients.

The aim of this study was to identify risk factors for tracheobronchial acquisition with the most common resistant Gram-negative bacteriain the intensive care unit (ICU) during the first week after intubation and mechanical ventilation. Tracheobronchial and oropharyngeal cultures were obtained at admission, after 48 hours, and after 7 days of mechanical ventilation. Patient characteristics, interventions, and antibiotic usage were recorded. Among 71 eligible patients with two negative bronchial cultures for resistant Gram-negative bacteria(at admission and within 48 hours), 41 (58%) acquired bronchial resistant Gram-negative bacteriaby day 7. Acquisition strongly correlated with presence of the same pathogens in the oropharynx: Acinetobacter baumannii[odds ratio (OR) = 20·2, 95% confidence interval (CI): 5·5–73·6], Klebsiella pneumoniae (OR = 8·0, 95% CI: 1·9–33·6), and Pseudomonas aeruginosa (OR = 27, 95%: CI 2·7–273). Bronchial acquisition with resistant K. pneumoniae also was associated with chroni...