title: Risk factors for ventilator associated pneumonia due to carbapenemase-producing Klebsiella pneumoniae in mechanically ventilated patients with tracheal and rectal colonization.
abstract: The aim of this study was to identify the risk factors for ventilator associated pneumonia (VAP) due to Klebsiella pneumoniae carbapenemase-producing K (KPC-Kp) development in ICU patients with documented rectal and tracheal colonization.
  
  
  
  We performed a retrospective, matched case-control study in a medical-surgical ICU (January 2011-December 2013) comparing 30 patients who developed KPC-Kp VAP during the ICU stay to 60 colonized patients not developing KPC-Kp VAP. Analysed risk factors included: age, sex, SAPS II and SOFA scores, comorbidities, type and length of antibiotic therapy, previous non KPC-Kp infections, time between admission to rectal and tracheal colonization.
  
  
  
  Several risk factors were more frequent among patients who developed KPC-Kp pneumonia versus matched colonized controls: previous infection not related to KPC-Kp (P<0.001), duration of previous antibiotic therapy before (P<0.001) and after (P=0.002) KPC-Kp colonization. Amoxicillin/clavulanic acid prophylaxis was administered in 17% of VAP patients versus 73% of patients not developing VAP (P<0.001). Multivariate conditional logistic regression analysis identified several significant independent risk factors favoring KPC-Kp VAP in patients colonized at multiple sites: previous non KPC-Kp infections (OR: 2.046), duration of previous antibiotic therapy before (OR: 1.309) and after (OR: 1.122) KPC-Kp colonization; antibiotic therapy with amoxicillin/clavulanic acid prophylaxis (<48 hours) was associated with reduced risk of KPC-Kp VAP (OR: 0.987).
  
  
  
  In rectal and tracheal KPC-Kp colonized patients, prolonged antibiotic therapy administered for non KPC-Kp infection predisposes patients to subsequent KPC-Kp VAP. Short prophylaxis of early pneumonia with amoxicillin/clavulanic acid, reducing the need for subsequent antibiotic use, may be associated with reduced risk for KPC-Kp VAP.
authors.affiliation: U.O. Lipidoaferesi, Fondazione Toscana Gabriele Monasterio, Pisa, Italy - francesco.sbrana@ftgm.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sbrana
authors.forename: Paolo
authors.initials: P
authors.lastname: Malacarne
authors.forename: Matteo
authors.initials: M
authors.lastname: Bassetti
authors.forename: Carlo
authors.initials: C
authors.lastname: Tascini
authors.forename: Lara
authors.initials: L
authors.lastname: Vegnuti
authors.forename: Paola
authors.initials: P
authors.lastname: Della Siega
authors.forename: Andrea
authors.initials: A
authors.lastname: Ripoli
authors.forename: Filippo
authors.initials: F
authors.lastname: Ansaldi
authors.forename: Francesco
authors.initials: F
authors.lastname: Menichetti
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000096:biosynthesis*; D002353:Carrier State / Q000382:microbiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000382:microbiology* / Q000517:prevention & control; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000382:microbiology* / Q000517:prevention & control; D012007:Rectum / Q000382:microbiology*; D012189:Retrospective Studies; D012307:Risk Factors; D014132:Trachea / Q000382:microbiology*; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases; C063912:carbapenemase