COMPARISON OF THE BACTERIAL ETIOLOGY OF EARLY-ONSET VENTILATOR-ASSOCIATED PNEUMONIA AND LATE-ONSET VENTILATOR-ASSOCIATED PNEUMONIA IN PATIENTS ENROLLED IN 2 LARGE CLINICAL STUDIES

Abstract

Purpose: To assess potential differences in bacterial etiology of subjects with early-onset vs. late-onset ventilator associated pneumonia (VAP). Methods: Subjects enrolled in 2004-2006 in 2 clinical studies of doripenem vs. imipenem or piperacillin/tazobactam with a diagnosis of VAP (N=500) were included in the analysis. Subjects were classified by ventilator status [early-onset VAP ( 5 days of ventilation)]. Baseline demographics and bacterial etiology were analyzed by VAP status. Results: Late-onset VAP subjects had higher APACHE II scores [mean 16.6 vs. 15.5 (p=0.008)]. There were no significant differences in CPIS, gender, age, or presence of bacteremia between groups. A total of 496 subjects had a baseline pathogen and 50% of subjects in each group had >2 pathogens. With the exception of Staphylococcus aureus, which was common in early-onset VAP, pathogens, including potentially MDR, isolated from early vs. late-onset VAP was not significantly different between groups. Acinetobacter baumannii or Pseudomonas aeruginosa with decreased susceptibility to any study drug was observed in early and late onset VAP subjects. Conclusion: There were no significant differences in the prevalence of potential MDR pathogens associated with early or late-onset VAP, even in subjects with prior antibiotics. Clinical Implications: VAP is classified as early-onset or late-onset, in part, to identify subjects at risk for infection with resistant pathogens. Empiric therapy for early-onset VAP should also include agents likely to be effective for potential MDR pathogens. Further prospective studies should evaluate microbiology trends in subjects with VAP. RESPIRATORY CARE Paper in Press. Published on January 08, 2013 as DOI: 10.4187/respcare.02173 Epub ahead of print papers have been peer-reviewed and accepted for publication but are posted before being copy edited and proofread, and as a result, may differ substantially when published in final version in the online and print editions of RESPIRATORY CARE. Copyright (C) 2013 Daedalus Enterprises