title: Risk factors and influence of carbapenem exposure on the development of carbapenem resistant Pseudomonas aeruginosa bloodstream infections and infections at sterile sites.
abstract: BACKGROUND
  Patients with Pseudomonas aeruginosa infections from blood or sterile sites were evaluated to determine risk factors associated with carbapenem resistance (CRPA) compared to carbapenem sensitivity (CSPA) as well as prior carbapenem use and the development of resistance.
  
  
  RESULTS
  Retrospective chart review of 80 patients hospitalized with a documented P. aeruginosa infection during 2010-2011. Stored isolates were retested with both Kirby-Bauer disk diffusion and E-tests. Clinical characteristic of patients in the CRPA (N = 21) and the CSPA (N = 59) groups were similar. Hospital acquired (HA) infections were more common in the CRPA group compared to the CSPA group (71 vs 44 %, p = 0.04) and CRPA patients were more likely to have a Foley catheter at the time of infection (71 vs 37 %, p = 0.01). There was more carbapenem use in the CRPA group prior to onset of infection (59 vs 22 %, OR 5.1, 95 % CI 1.3-20.8, p = 0.01). Length of stay was significantly longer in the CRPA group (mean 44 days) compared to the CSPA group (mean 23 days), p = 0.02. Mortality between the two groups was similar and there were no differences between groups for death attributable to Pseudomonas.
  
  
  CONCLUSIONS
  Patients with CRPA were more likely to have HA infections and to have a multidrug resistant profile. Other identifiable risks included a Foley catheter in place at the time of infection and exposure to a carbapenem prior to infection. Prompt removal of devices and judicious use of antibiotics may be interventions that can impact the development of this kind of infections.
authors.affiliation: Division of Infectious Diseases, University of Colorado Denver, 12700 E. 19th Ave, B168, Aurora, CO 80045 USA.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Barron
authors.affiliation: Division of Infectious Diseases, University of Colorado Denver, 12700 E. 19th Ave, B168, Aurora, CO 80045 USA.
authors.forename: Kris
authors.initials: K
authors.lastname: Richardson
authors.affiliation: Department of Clinical Pharmacy, Skaggs School of Pharmacy and Pharmaceutical Science, University of Colorado Denver, Mail Stop C 238, 12850 E. Montview Blvd, V20-1212, Aurora, CO 80045 USA.
authors.forename: Meghan
authors.initials: M
authors.lastname: Jeffres
authors.affiliation: Division of Infectious Diseases, University of Colorado Denver, 12700 E. 19th Ave, B168, Aurora, CO 80045 USA.
authors.forename: Bruce
authors.initials: B
authors.lastname: McCollister
keywords: Antibiotic resistance; Carbapenem resistance; Pseudomonas aeruginosa