Blood Culture


Indications

Evaluation of Fever/Diagnosis of Bacteremia/Evaluation of Sepsis (see Fever, Bacteremia, and Sepsis)

Rationale

  • Isolation of the Etiologic Organism(s) Allows for Identification of the Responsible Microorganism, Determining the Sensitivity Pattern, and Allows for Later Antibiotic De-Escalation
  • In General, Routine “Panculture” of All Available Sites is Not Recommended (Unless the Clinical Source of Sepsis is Not Readily Apparent), Due to the Risk of Inappropriate Antimicrobial Use (BMJ Qual Saf, 2017) [MEDLINE]

Clinical Efficacy

  • Presence of Bacteremia
    • Only 50% of Patients are Bacteremic at the Time of Sepsis Diagnosis (Crit Care Med, 1989) [MEDLINE]
    • Canadian Study of Blood Cultures for Sepsis in the Emergency Department Before and After Antibiotic Administration (Ann Intern Med, 2019) [MEDLINE]: n = 325
      • Pre-Antimicrobial Blood Cultures were Positive for ≥1 Microbial Pathogens in 31.4% of Patients
      • When the Results of Other Microbiological Cultures were Included, Microbial Pathogens were Found in 67.6% of Patients (CI: 57.7% to 76.6%)
  • Blood Culture Yield is Not Improved with Sequential Draws or Timing with Fever Spikes
  • Sterilization by Antimicrobial Therapy
    • Sterilization of Cultures May Occur within Minutes-Hours of Antibiotic Administration (Clin Infect Dis, 2013) [MEDLINE] and (Pediatrics, 2001) [MEDLINE]
    • Canadian Study of Blood Cultures for Sepsis in the Emergency Department Before and After Antibiotic Administration (Ann Intern Med, 2019) [MEDLINE]: n = 325
      • Pre-Antimicrobial Blood Cultures were Positive for ≥1 Microbial Pathogens in 31.4% of Patients
      • Post-Antimicrobial Blood Cultures were Positive for ≥1 Microbial Pathogens in 19.4% of Patients: sensitivity of post-antimicrobial culture was 52.9% (CI: 42.8% to 62.9%)
  • Antibiotic Stewardship Data from the 2014 National Healthcare Safety Network Annual Hospital Survey (Clin Infect Dis, 2016) [MEDLINE]
    • De-Escalation of Antibiotic Therapy is Associated with Less Resistant Microorganisms, Fewer Side Effects, and Lower Costs
    • Blood Cultures are Required to Facilitate Future Antibiotic De-Escalation When the Organism is Identified and its Sensitivity is Elucidated
      • De-Escalation of Antibiotic Therapy is Associated with Less Resistant Microorganisms, Fewer Side Effects, and Lower Costs (Clin Infect Dis, 2016) [MEDLINE]
    • Blood Culture Antigen Detection Assays (VERIGENE, etc) are Routinely Utilized to Rapidly Identify the Organism and its Resistance Pattern

Recommendations (2016 Surviving Sepsis Guidelines; Intensive Care Med, 2017) [MEDLINE]

  • Routine (Appropriate) Cultures are Recommended Prior to Starting Antibiotic Therapy in Patients with Suspected Sepsis (Best Practice Statement): assuming that this results in no significant delay (<45 min) in starting antibiotics
  • At Least Two Sets of Blood Cultures (Aerobic and Anaerobic) with a Single Time of Draw are Recommended (Best Practice Statement)
  • In Patients with an Intravascular Catheter in Place with a Suspicion of Line-Related Sepsis, at Least One Set of Blood Cultures Should Be Obtained from the Catheter (with Simultaneous Peripheral Blood Cultures)
  • In Patients with an Intravascular Catheter in Place without a Suspicion of Line-Related Sepsis, at Least One Set of Blood Cultures Should Be Obtained Peripherally (No Recommendation is Made Regarding the Second Site of Blood Culture)

Technique


References