[Comparision of risk factors and pathogens in patients with early- and late-onset ventilator-associated pneumonia in intensive care unit].

Objective: To compare risk factors and bacterial etiology in patients with early-onset versus late-onset ventilator-associated pneumonia (VAP) in intensive care unit (ICU). Methods: This prospective cohort study enrolled mechanically ventilated patients hospitalized for more than 48 hours in the first affiliated hospital, China Medical University from Jan 2012 to Jun 2016. Subjects were classified by ventilator status: early-onset VAP (< 5 d ventilation, E-VAP) or late-onset VAP (≥ 5 d ventilation, L-VAP). Potential risk factors and pathogen were evaluated. Results: A total of 4 179 patients in adult ICU were screened, 3 989 (95.5%) of whom were mechanically ventilated, 962 patients with mechanical ventilation time ≥ 48 h. VAP developed in 142 patients. E-VAP and L-VAP had different potential risk factors based on statistical analysis.Independent risk factors for E-VAP included male (OR=1.825, 95%CI 1.006-3.310), chronic obstructive pulmonary disease (COPD; OR=3.746, 95%CI 1.795-7.818), emergency intubation (OR=1.932, 95%CI 1.139-3.276), aspiration (OR=3.324, 95%CI 1.359-8.130). Whereas independent risk factors for L-VAP were coma (OR=2.335, 95%CI 1.300-4.194), renal dysfunction (OR=0.524, 95%CI 0.290-0.947), emergency intubation (OR=2.184, 95%CI 1.334-3.574). Mortality in E-VAP and L-VAP group were both higher than the non-VAP group[30.2%(19/63)vs 19.8%(162/820), P=0.044; 29.1%(23/79) vs 19.8%(162/820), P=0.046]. The pathogens isolated from early-onset versus late-onset VAP were not significantly different between groups, which the most common ones were acinetobacter baumannii, pseudomonas aeruginosa and klebsiella pneumoniae. Conclusion: E-VAP and L-VAP have different risk factors, however related pathogens are similar. Different specific preventive strategies are suggested based on different onset of VAP.