Lab

Blood Culture

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Blood Culture

  1. Bacteremia
  2. Sepsis
  • Technique
  1. Preparation of skin
    1. Chlorhexidine (preferred agent for antiseptic)
      1. Superior to povidone-Iodine
      2. Superior to Alcohol
    2. Povidone-Iodine
      1. Wait to draw blood for 2-3 minutes after applying
      2. High contamination rate compared with Chlorhexidine
    3. References
      1. Mimoz (1999) Ann Intern Med 131:834-7 [PubMed]
  2. Standard collection protocol
    1. Collect up to 3-4 sets of Blood Culture bottles
      1. Two Blood Culture bottles in each set
      2. Obtain 5 ml blood per bottle
    2. Draw from up to 3 different venipuncture sites
    3. Space blood collections by 1 hour intervals
  3. New collection protocol: Six bottle method
    1. Collect 6 bottles from one venipuncture (total 40 ml)
    2. Based on mathematical model
    3. Predicts highest sensitivity and Specificity
    4. References
      1. Lamy (2002) Clin Infect Dis 35:842-50 [PubMed]
  • Efficacy
  1. Sensitivity
    1. Increases with number of Blood Cultures drawn
    2. With 3 Blood Cultures, Sensitivity approaches 90%
  2. Study of hospitalized patients with persistent fever
    1. Post-antibiotic culture unlikely to yield pathogen
    2. Obtain pre-antibiotic Blood Culture and await results
    3. Grace (2001) Clin Infect Dis 32:1651-5 [PubMed]