title: Costs and length of stay associated with antimicrobial resistance in acute kidney injury patients with bloodstream infection.
abstract: BACKGROUND
  Antimicrobial resistance negatively impacts on prognosis. Intensive care unit (ICU) patients, and particularly those with acute kidney injury (AKI), are at high risk for developing nosocomial bloodstream infections (BSI) due to multi-drug-resistant strains. Economic implications in terms of costs and length of stay (LOS) attributable to antimicrobial resistance are underevaluated. This study aimed to assess whether microbial susceptibility patterns affect costs and LOS in a well-defined cohort of ICU patients with AKI undergoing renal replacement therapy (RRT) who developed nosocomial BSI.
  
  
  METHODS
  Historical study (1995-2004) enrolling all adult RRT-dependent ICU patients with AKI and nosocomial BSI. Costs were considered as invoiced in the Belgian reimbursement system, and LOS was used as a surrogate marker for hospital resource allocation.
  
  
  RESULTS
  Of the 1330 patients with AKI undergoing RRT, 92 had microbiologic evidence of nosocomial BSI (57/92, 62% due to a multi-drug-resistant microorganism). Main patient characteristics were equal in both groups. As compared to patients with antimicro-4 bial-susceptible BSI, patients with antimicrobial-resistant BSI were more likely to acquire Gram-positive infection (72.6% vs 25.5%, P<0.001). No differences were found neither in LOS (ICU before BSI, ICU, hospital before BSI, hospital, hospital after BSI, and time on RRT; all P>0.05) or hospital costs (all P>0.05) when comparing patients with antimicrobial-resistant vs antimicrobial-susceptible BSI. However, although not statistically significant, patients with BSI caused by resistant Gram-negative-, Candida-, or anaerobic bacteria incurred substantial higher costs than those without.
  
  
  CONCLUSIONS
  In a cohort of ICU patients with AKI and nosocomial BSI undergoing RRT, patients with antimicrobial-resistant vs antimicrobial-susceptible Gram-positive BSI did not have longer hospital stays, or higher hospital costs. Patients with resistant "other" (i.e. Gram-negative, Candida, or anaerobic) BSI were found to have a distinct trend towards increased resources use as compared to patients with susceptible "other" BSI, respectively.
authors.affiliation: Faculty of Medicine and Health Sciences, Ghent University, Ghent University Hospital, Department of Intensive Care Medicine, Belgium. Dominique.Vandijck@UGent.be
authors.forename: D M
authors.initials: DM
authors.lastname: Vandijck
authors.forename: S I
authors.initials: SI
authors.lastname: Blot
authors.forename: J M
authors.initials: JM
authors.lastname: Decruyenaere
authors.forename: R C
authors.initials: RC
authors.lastname: Vanholder
authors.forename: J J
authors.initials: JJ
authors.lastname: De Waele
authors.forename: N H
authors.initials: NH
authors.lastname: Lameire
authors.forename: S
authors.initials: S
authors.lastname: Claus
authors.forename: J
authors.initials: J
authors.lastname: De Schuijmer
authors.forename: A W
authors.initials: AW
authors.lastname: Dhondt
authors.forename: G
authors.initials: G
authors.lastname: Verschraegen
authors.forename: E A
authors.initials: EA
authors.lastname: Hoste
mesh_terms: D058186:Acute Kidney Injury / Q000191:economics* / Q000382:microbiology / Q000628:therapy; D000368:Aged; D016470:Bacteremia / Q000150:complications / Q000191:economics* / Q000628:therapy; D015331:Cohort Studies; D003428:Cross Infection / Q000150:complications / Q000191:economics / Q000628:therapy; D024881:Drug Resistance, Bacterial; D005260:Female; D017048:Health Care Costs; D006801:Humans; D007902:Length of Stay / Q000191:economics; D008297:Male; D008875:Middle Aged; D017582:Renal Replacement Therapy; D012189:Retrospective Studies