title: Risk factors for multidrug-resistant bacteria in patients with post-operative peritonitis requiring intensive care.
abstract: OBJECTIVE
  This prospective non-interventional study investigated the risk factors for multidrug-resistant bacteria (MDRB) in patients with post-operative peritonitis (POP), to provide guidance for empirical antimicrobial therapy.
  
  
  METHODS
  All consecutive patients, >15 years old, admitted to a surgical intensive care unit (ICU) between September 2006 and January 2009 for a first episode of POP were included. Antibiotic susceptibilities of microorganisms recovered from blood cultures and peritoneal fluid were determined by disc diffusion. Amoxicillin/clavulanic acid, ticarcillin/clavulanic acid, piperacillin/tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, gentamicin, amikacin and ciprofloxacin were tested against Gram-negative bacteria, and oxacillin, amoxicillin, vancomycin, gentamicin and erythromycin were tested against aerobic Gram-positive bacteria. Results were reported as susceptible or resistant.
  
  
  RESULTS
  MDRB were isolated from 20/115 (17%) patients. In univariate analysis, use of antimicrobial therapy during the 3 months prior to hospitalization and a long duration between hospital admission or first operation and relaparotomy were significantly associated with MDRB recovery. In multivariate analysis, only antimicrobial treatment in the 3 months preceding hospitalization and duration between first operation and relaparotomy were independent risk factors for MDRB [odds ratio (OR) = 5.80, 95% confidence interval (95% CI) = 1.99-16.91 and OR = 1.10, 95% CI = 1.02-1.19, respectively]. No MDRB were found when the delay between the first operation and relaparotomy was <5 days. POP severity, non-surgical and surgical complications, hospital and ICU length of stay, and mortality were similar in patients with and without MDRB.
  
  
  CONCLUSIONS
  Our results suggest that broad-spectrum antibiotics should be used in ICU patients with POP who have received antimicrobial therapy in the 3 months prior to hospitalization, or with >5 days between the first operation and relaparotomy.
authors.affiliation: Service de Réanimation Chirurgicale, Université Rennes 1, INSERM U991, Hôpital de Pontchaillou, 2 rue Henri Le Guilloux, 35033 Rennes Cedex 9, Rennes, France. philippe.seguin@chu-rennes.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Seguin
authors.forename: Yannick
authors.initials: Y
authors.lastname: Fédun
authors.forename: Bruno
authors.initials: B
authors.lastname: Laviolle
authors.forename: Nicolas
authors.initials: N
authors.lastname: Nesseler
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Donnio
authors.forename: Yannick
authors.initials: Y
authors.lastname: Mallédant
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D001424:Bacterial Infections / Q000382:microbiology*; D003422:Critical Care; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D010538:Peritonitis / Q000382:microbiology*; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents