@article {Restrepo1220, author = {Marcos I Restrepo and Janet Peterson and Juan F Fernandez and Zhihai Qin and Alan C Fisher and Susan C Nicholson}, title = {Comparison of the Bacterial Etiology of Early-Onset and Late-Onset Ventilator-Associated Pneumonia in Subjects Enrolled in 2 Large Clinical Studies}, volume = {58}, number = {7}, pages = {1220--1225}, year = {2013}, doi = {10.4187/respcare.02173}, publisher = {Respiratory Care}, abstract = {BACKGROUND: Ventilator-associated pneumonia (VAP) is classified as early-onset or late-onset, in part, to identify subjects at risk for infection with resistant pathogens. We assessed differences in the bacterial etiology of early-onset versus late-onset VAP. METHODS: Subjects enrolled in 2004{\textendash}2006 in 2 clinical studies of doripenem versus 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 d of ventilation) or late-onset VAP (>= 5 d of ventilation). Baseline demographics and bacterial etiology were analyzed by VAP status. RESULTS: Late-onset VAP subjects had higher Acute Physiology and Chronic Health Evaluation (APACHE II) scores (mean 16.6 versus 15.5, P = .008). There were no significant differences in Clinical Pulmonary Infection Score, sex, age, or presence of bacteremia between the 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, the pathogens (including potentially multidrug-resistant (MDR) pathogens) isolated from early-onset versus late-onset VAP were not significantly different between groups. Acinetobacter baumannii or Pseudomonas aeruginosa with decreased susceptibility to any study drug was observed in early-onset and late-onset VAP subjects. CONCLUSIONS: There were no significant differences in the prevalence of potential MDR pathogens associated with early-onset or late-onset VAP, even in subjects with prior antibiotics. 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.}, issn = {0020-1324}, URL = {https://rc.rcjournal.com/content/58/7/1220}, eprint = {https://rc.rcjournal.com/content/58/7/1220.full.pdf}, journal = {Respiratory Care} }