title: How many lumens should be cultured in the conservative diagnosis of catheter-related bloodstream infections?
abstract: BACKGROUND
  Recent practice guidelines for the diagnosis of catheter-related bloodstream infection (CRBSI) describe as an "unresolved issue" the number of lumens from which blood culture specimens should be drawn to make a conservative diagnosis of CRBSI. Our objective was to determine how many CRBSI episodes would be missed if not all catheter lumens were sampled.
  
  
  METHODS
  We performed a retrospective study (1 January 2003-31 May 2009) in patients with microbiologically proven CRBSI in which all available catheter lumens (those that did not contain clots) were used to draw blood culture samples. We calculated the number of episodes that would have been missed in double- and triple-lumen catheters if the culture of samples obtained from 1 lumens had been eliminated.
  
  
  RESULTS
  We studied 171 episodes of proven CRBSI in 154 patients. Overall, if 1 lumen-associated culture had been eliminated for both double-lumen and triple-lumen catheters, we would have missed 27.2% and 15.8% of episodes of CRBSI, respectively. If we had eliminated 2 cultures for triple-lumen catheters, 37.3% of episodes would have been missed.
  
  
  CONCLUSIONS
  Samples for blood culture should be obtained through all catheter lumens to establish a diagnosis of CRBSI.
authors.affiliation: Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Universidad Complutense, Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Guembe
authors.forename: Marta
authors.initials: M
authors.lastname: Rodríguez-Créixems
authors.forename: Carlos
authors.initials: C
authors.lastname: Sánchez-Carrillo
authors.forename: Alfonso
authors.initials: A
authors.lastname: Pérez-Parra
authors.forename: Pablo
authors.initials: P
authors.lastname: Martín-Rabadán
authors.forename: Emilio
authors.initials: E
authors.lastname: Bouza
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D001419:Bacteria / Q000302:isolation & purification; D055499:Catheter-Related Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D002404:Catheterization / Q000009:adverse effects; D015169:Colony Count, Microbial; D003428:Cross Infection / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D046508:Culture Techniques; D005260:Female; D016469:Fungemia / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015003:Yeasts / Q000302:isolation & purification