Blood Culture, Routine Synonyms Culture, Blood

Applies to Aerobic Blood Culture; Anaerobic Blood Culture; Blood Culture, Aerobic/Anaerobic

Test Includes Isolation and identification of both anaerobic and aerobic microorganisms; susceptibility testing is performed on all significant aerobic isolates.

Laboratory Clinical Microbiology, BHS-03-312

Request Form Microbiology

Phone (212) 305-6276

Availability Daily, 24 hours

Turnaround Time 6 days for final culture report; all positive blood cultures are reported immediately by phone and written report.

Special Instructions The following information must be provided to the laboratory for the proper processing of the specimen: current antibiotic therapy, age and sex of patient, collection time and date, physician's name and pager number, and clinical diagnosis.

Specimen Blood

Volume Pediatrics: 1-5 mL (1-5 mL per bottle); adults: 16-20 mL (8-10 mL per bottle)

Minimum Volume Pediatrics: 0.5 mL per bottle; adults: 5 mL per bottle

Container Pediatrics: Peds Plus bottle; adults: standard 10 aerobic/F and lytic/10 anaerobic/F

Collection Blood cultures should be drawn prior to initiation of antimicrobial therapy. If more than one culture is ordered, the specimens should be drawn from separately prepared sites. A syringe and needle, transfer set or pre-evacuated set of tubes containing culture media may be used to collect blood. Collection tubes should be held below the level of the venipuncture to avoid reflux. A sample volume of 20 mL in adults, 1-5 mL in pediatric patients is usually collected for each set. If a syringe and needle or transfer set is used, the top of the blood culture bottles should also be aseptically prepared. The following protocol may be followed for drawing blood cultures under varying conditions:

Sepsis, meningitis, osteomyelitis, septic arthritis, bacterial pneumonia: two sets of cultures - one from each of two prepared sites, the second drawn after a brief time interval, then begin therapy.

Fever of unknown origin (eg, occult abscess, empyema, typhoid fever, etc): two sets of cultures - one from each of two prepared sites, the second drawn after a brief time interval (30 minutes). If cultures are negative after 24-48 hours, obtain two more sets, preferably prior to an anticipated temperature rise.

Endocarditis (acute): Obtain three blood culture sets within 2 hours, then begin therapy.

Endocarditis (subacute): Obtain three culture sets on day 1, repeat if negative after 24 hours. If still negative or if the patient had prior antibiotic therapy, repeat again.

Immunocompromised host (eg, AIDS), septicemia, fungemia, mycobacteremia: Obtain two sets of cultures from each of two prepared sites; consider lysis concentration technique (Isolator^TM tube) to enhance recovery for fungi and mycobacteria.

Transient bacteremia caused by brushing teeth, bowel movements, etc or by local irritations caused by scratching of the skin, may cause positive blood cultures as can contamination by skin flora at the time of collection. Interpretation of results can be enhanced by collecting blood cultures from more than one site and after a time interval (15-30 minutes). Cultures should be taken as early as possible in the course of a febrile episode.

Storage Instructions Transport specimen to the laboratory immediately. Do not refrigerate.

Patient Preparation Collect under aseptic conditions. See procedure in Bacteriology section of Appendix.

Aftercare Iodine used in the skin preparation should be carefully removed from the skin after venipuncture.

Reference Range No growth

Use Isolate and identify potentially pathogenic organisms causing bacteremia, septicemia, etc

Methodology Bactec® culture system