title: Duodenoscope hang time does not correlate with risk of bacterial contamination.
abstract: BACKGROUND
  Current professional guidelines recommend a maximum hang time for reprocessed duodenoscopes of 5-14 days. We sought to study the association between hang time and risk of duodenoscope contamination.
  
  
  METHODS
  We analyzed cultures of the elevator mechanism and working channel collected in a highly standardized fashion just before duodenoscope use. Hang time was calculated as the time from reprocessing to duodenoscope sampling. The relationship between hang time and duodenoscope contamination was estimated using a calculated correlation coefficient between hang time in days and degree of contamination on the elevator mechanism and working channel.
  
  
  RESULTS
  The 18 study duodenoscopes were cultured 531 times, including 465 (87.6%) in the analysis dataset. Hang time ranged from 0.07-39.93 days, including 34 (7.3%) with hang time ≥7.00 days. Twelve cultures (2.6%) demonstrated elevator mechanism and/or working channel contamination. The correlation coefficients for hang time and degree of duodenoscope contamination were very small and not statistically significant (-0.0090 [P = .85] for elevator mechanism and -0.0002 [P = 1.00] for working channel). Odds ratios for hang time (dichotomized at ≥7.00 days) and elevator mechanism and/or working channel contamination were not significant.
  
  
  CONCLUSIONS
  We did not find a significant association between hang time and risk of duodenoscope contamination. Future guidelines should consider a recommendation of no limit for hang time.
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA.
authors.forename: Riley
authors.initials: R
authors.lastname: Heroux
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Sheppard
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA; Harvard Medical School, Boston, MA.
authors.forename: Sharon B
authors.initials: SB
authors.lastname: Wright
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA; Harvard Medical School, Boston, MA.
authors.forename: Mandeep
authors.initials: M
authors.lastname: Sawhney
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA; Northeastern University, Boston, MA.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Hirsch
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA.
authors.forename: Robin
authors.initials: R
authors.lastname: Kalaidjian
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA; Harvard Medical School, Boston, MA. Electronic address: gsnyder@bidmc.harvard.edu.
authors.forename: Graham M
authors.initials: GM
authors.lastname: Snyder
mesh_terms: D020698:Duodenoscopes / Q000382:microbiology*; D004866:Equipment Contamination; D008828:Microbiological Techniques; D018570:Risk Assessment; D013997:Time Factors
keywords: Disinfection; ERCP; Endoscope; Environmental contamination