title: Factors influencing the implementation of antibiotic de-escalation and impact of this strategy in critically ill patients.
abstract: BACKGROUND
  A rational use of antibiotics is of paramount importance in order to prevent the emergence of multidrug resistant bacteria that can lead to therapeutic impasse, especially in intensive care units (ICUs). A de-escalation strategy is therefore naturally advocated as part of better antibiotics usage. However, the clinical impact of such a strategy has not been widely studied. We aimed to assess the feasibility and the clinical impact of a de-escalation strategy in a medical ICU and to identify factors associated when de-escalation was possible.
  
  
  METHODS
  We performed a retrospective study of patients hospitalized in a medical ICU over a period of six months. Independent factors associated with de-escalation and its clinical impact were assessed.
  
  
  RESULTS
  Two hundred and twenty-nine patients were included in the study. Antibiotics were de-escalated in 117 patients (51%). The appropriateness of initial antibiotic therapy was the only independent factor associated with the performance of de-escalation (OR = 2.9, 95% CI, 1.5-5.7; P = 0.002). By contrast, inadequacy of initial antibiotic therapy (OR = 0.1, 0.0 to 0.1, P <0.001) and the presence of multidrug resistant bacteria (OR = 0.2, 0.1 to 0.7, P = 0.006) prevented from de-escalation. There were no differences in terms of short (ICU) or long-term (at 1 year) mortality rates or any secondary criteria such as ICU length of stay, duration of antibiotic therapy, mechanical ventilation, incidence of ICU-acquired infection, or multi-drug resistant bacteria emergence.
  
  
  CONCLUSIONS
  De-escalation appears feasible in most cases without any obvious negative clinical impact in a medical ICU.
authors.forename: Leslie
authors.initials: L
authors.lastname: Gonzalez
authors.forename: Aurélie
authors.initials: A
authors.lastname: Cravoisy
authors.forename: Damien
authors.initials: D
authors.lastname: Barraud
authors.forename: Marie
authors.initials: M
authors.lastname: Conrad
authors.forename: Lionel
authors.initials: L
authors.lastname: Nace
authors.forename: Jérémie
authors.initials: J
authors.lastname: Lemarié
authors.forename: Pierre-Edouard
authors.initials: PE
authors.lastname: Bollaert
authors.forename: Sébastien
authors.initials: S
authors.lastname: Gibot
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001424:Bacterial Infections / Q000517:prevention & control*; D003422:Critical Care / Q000379:methods*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012772:Shock, Septic / Q000188:drug therapy; D016896:Treatment Outcome; D028761:Withholding Treatment
chemical_list: D000900:Anti-Bacterial Agents