title: Imipenem-resistant Pseudomonas aeruginosa infection at a medical-surgical intensive care unit: risk factors and mortality.
abstract: OBJECTIVE
  The aim of this study was to evaluate the risk factors and attributable mortality associated with imipenem-resistant Pseudomonas aeruginosa (IRPA) infections in a medical-surgical intensive care unit (ICU).
  
  
  METHODS
  A retrospective case-control study was carried out at a 16-bed medical-surgical ICU in a 780-bed, university-affiliated hospital. All patients admitted from January 1, 2003, to December 31, 2004, who had nosocomial infection caused by IRPA, were included in the study.
  
  
  RESULTS
  Imipenem-resistant P. aeruginosa was recovered from 63 patients during the study period. One hundred eighty-two controls were matched with cases by period of admission, age, and time at risk. Urinary tract (34.9%) and respiratory tract (22.2%) were the main sources of IRPA isolation. In multivariate analysis, a previous stay in the ICU (odds ratio, 3.54; 95% confidence interval [CI], 1.29-9.73; P = .03) was the only independent risk factor for IRPA infection. The in-hospital mortality rate among case patients was 49% (31 of 63) compared with 33% (61 of 182) for control patients (odds ratio, 1.92; 95% CI, 1.07-3.44; P = .02). Thus, we had an attributable mortality of 16% (95% CI, 9.74%-22.3%; P = .03).
  
  
  CONCLUSIONS
  Our study suggests that IRPA infections are strongly related to previous ICU stay, and that IRPA infections significantly increase mortality in those critical patients.
authors: Hospital Epidemiology Committee, Division of Infectious Diseases, Federal University of São Paulo, São Paulo, Brazil. ghfurtado@uol.com.br
authors: Guilherme H C
authors: GH
authors: Furtado
authors: Maria D
authors: MD
authors: Bergamasco
authors: Fernando G
authors: FG
authors: Menezes
authors: Daniel
authors: D
authors: Marques
authors: Adriana
authors: A
authors: Silva
authors: Luciana B
authors: LB
authors: Perdiz
authors: Sérgio B
authors: SB
authors: Wey
authors: Eduardo A S
authors: EA
authors: Medeiros
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000494:pharmacology*; D016022:Case-Control Studies; D024881:Drug Resistance, Bacterial; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000382:microbiology / Q000401:mortality*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000890:Anti-Infective Agents; D015378:Imipenem