title: Does chlorhexidine bathing in adult intensive care units reduce blood culture contamination? A pragmatic cluster-randomized trial.
abstract: OBJECTIVE
  To determine rates of blood culture contamination comparing 3 strategies to prevent intensive care unit (ICU) infections: screening and isolation, targeted decolonization, and universal decolonization.
  
  
  METHODS
  Pragmatic cluster-randomized trial.
  
  
  METHODS
  Forty-three hospitals with 74 ICUs; 42 of 43 were community hospitals.
  
  
  METHODS
  Patients admitted to adult ICUs from July 1, 2009, to September 30, 2011.
  
  
  METHODS
  After a 6-month baseline period, hospitals were randomly assigned to 1 of 3 strategies, with all participating adult ICUs in a given hospital assigned to the same strategy. Arm 1 implemented methicillin-resistant Staphylococcus aureus (MRSA) nares screening and isolation, arm 2 targeted decolonization (screening, isolation, and decolonization of MRSA carriers), and arm 3 conducted no screening but universal decolonization of all patients with mupirocin and chlorhexidine (CHG) bathing. Blood culture contamination rates in the intervention period were compared to the baseline period across all 3 arms.
  
  
  RESULTS
  During the 6-month baseline period, 7,926 blood cultures were collected from 3,399 unique patients: 1,099 sets in arm 1, 928 in arm 2, and 1,372 in arm 3. During the 18-month intervention period, 22,761 blood cultures were collected from 9,878 unique patients: 3,055 sets in arm 1, 3,213 in arm 2, and 3,610 in arm 3. Among all individual draws, for arms 1, 2, and 3, the contamination rates were 4.1%, 3.9%, and 3.8% for the baseline period and 3.3%, 3.2%, and 2.4% for the intervention period, respectively. When we evaluated sets of blood cultures rather than individual draws, the contamination rate in arm 1 (screening and isolation) was 9.8% (N = 108 sets) in the baseline period and 7.5% (N = 228) in the intervention period. For arm 2 (targeted decolonization), the baseline rate was 8.4% (N = 78) compared to 7.5% (N = 241) in the intervention period. Arm 3 (universal decolonization) had the greatest decrease in contamination rate, with a decrease from 8.7% (N = 119) contaminated blood cultures during the baseline period to 5.1% (N = 184) during the intervention period. Logistic regression models demonstrated a significant difference across the arms when comparing the reduction in contamination between baseline and intervention periods in both unadjusted (P = .02) and adjusted (P = .02) analyses. Arm 3 resulted in the greatest reduction in blood culture contamination rates, with an unadjusted odds ratio (OR) of 0.56 (95% confidence interval [CI], 0.044-0.71) and an adjusted OR of 0.55 (95% CI, 0.43-0.71).
  
  
  CONCLUSIONS
  In this large cluster-randomized trial, we demonstrated that universal decolonization with CHG bathing resulted in a significant reduction in blood culture contamination.
authors.affiliation: Hospital Corporation of America, Nashville, Tennessee.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Septimus
authors.forename: Mary K
authors.initials: MK
authors.lastname: Hayden
authors.forename: Ken
authors.initials: K
authors.lastname: Kleinman
authors.forename: Taliser R
authors.initials: TR
authors.lastname: Avery
authors.forename: Julia
authors.initials: J
authors.lastname: Moody
authors.forename: Robert A
authors.initials: RA
authors.lastname: Weinstein
authors.forename: Jason
authors.initials: J
authors.lastname: Hickok
authors.forename: Julie
authors.initials: J
authors.lastname: Lankiewicz
authors.forename: Adrijana
authors.initials: A
authors.lastname: Gombosev
authors.forename: Katherine
authors.initials: K
authors.lastname: Haffenreffer
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Kaganov
authors.forename: John A
authors.initials: JA
authors.lastname: Jernigan
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Perlin
authors.forename: Richard
authors.initials: R
authors.lastname: Platt
authors.forename: Susan S
authors.initials: SS
authors.lastname: Huang
mesh_terms: D000368:Aged; D001494:Baths / Q000379:methods*; D002710:Chlorhexidine / Q000627:therapeutic use*; D003428:Cross Infection / Q000517:prevention & control*; D004202:Disinfectants / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus; D008875:Middle Aged; D009296:Nasal Cavity / Q000382:microbiology; D018805:Sepsis / Q000517:prevention & control*; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control
chemical_list: D004202:Disinfectants; D002710:Chlorhexidine