title: [Contamination of blood cultures drawn from central vein catheter and peripheral venipuncture. Prospective study of 75 pairs].
abstract: OBJECTIVE
  To determine the frequency of contamination, the sensitivity, specificity, and predictive values of cultures done with blood drawn through a central venous catheter or peripheral venipuncture.
  
  
  METHODS
  Prospective cohort study of critical ill medical surgical intensive care patients in whom samples for paired culture were drawn through a central venous catheter or peripheral venipuncture during a period of 8 months (from August 1st 2001 to Mars 31st 2002).
  
  
  RESULTS
  During the study period, 75-paired cultures were studied. Fifteen peripheral blood cultures (20%) and 27 central blood cultures (36%) were positive and 6 peripheral blood cultures (8%) and 15 central blood cultures (20%) were contaminated (P=0.034). The organism most commonly responsible for contamination was Coagulase Negative Staphylococcus (16% of central blood cultures and 6.7% of peripheral blood cultures). The frequency of contamination was of 42.9% for blood cultures drawn through a femoral central venous catheter, of 10% for jugular, and of 19% for subclavian central venous catheter (P=0.22). For catheter draws compared with peripheral venipuncture, sensitivity was 100 and 75%, specificity was 76.2 and 90.5%, positive predictive value was 44.4 and 60% and negative predictive value was 100 and 95%.
  
  
  CONCLUSIONS
  Cultures of blood drawn through a catheter are more sensible and less specific than those obtained from a peripheral venipuncture and the organism most commonly responsible for contamination of blood cultures is Coagulase Negative Staphylococcus.
authors.affiliation: Service de réanimation médicale, CHU Habib Bourguiba, route El-Ain, km 1, 3029 Sfax, Tunisie. Kallelhat@yahoo.fr
authors.forename: H
authors.initials: H
authors.lastname: Kallel
authors.forename: H
authors.initials: H
authors.lastname: Dammak
authors.forename: F
authors.initials: F
authors.lastname: Mahjoubi
authors.forename: M
authors.initials: M
authors.lastname: Bahloul
authors.forename: E
authors.initials: E
authors.lastname: Turki
authors.forename: H
authors.initials: H
authors.lastname: Chelly
authors.forename: N
authors.initials: N
authors.lastname: Rekik
authors.forename: A
authors.initials: A
authors.lastname: Hammami
authors.forename: M
authors.initials: M
authors.lastname: Bouaziz
mesh_terms: D001419:Bacteria / Q000145:classification / Q000302:isolation & purification*; D001800:Blood Specimen Collection / Q000592:standards*; D002405:Catheterization, Central Venous / Q000592:standards; D002406:Catheterization, Peripheral / Q000592:standards; D003422:Critical Care / Q000592:standards; D004866:Equipment Contamination / Q000706:statistics & numerical data*; D006801:Humans; D011446:Prospective Studies; D012121:Respiration, Artificial; D012680:Sensitivity and Specificity; D014680:Veins / Q000503:physiopathology*