Lab Dept:

Microbiology/Virology

Test Name:

BLOOD CULTURE

General Information

Lab Order Codes:

BC

Synonyms:

Culture, Blood; BC

CPT Codes:

87040 – Culture, bacterial; blood, with isolation and presumptive identification of isolates

The following testing may be added if appropriate based on findings for organism identification (multiple additions are possible if more than one organism is identified) and to aid in patient treatment management.

87076 – Anaerobic isolate, additional methods required for definitive identification of isolates
87077 – Aerobic isolate, additional methods required for definitive identification, each isolate (if appropriate)
87106 – Culture, fungi, definitive identification, each organism, yeast (if appropriate)
87107 – Culture, mold, definitive identification, each organism, mold (if appropriate)
87206 – Smear, primary source with interpretation, fluorescent and/or acid fast stain for bacteria, fungi or cell types (if appropriate)
87184 – Susceptibility studies, disk method, per plate (if appropriate)
87185 – Enzyme detection (eg, beta lactamase), per enzyme (if appropriate)
87186 – Susceptibility studies, microdilution or agar dilution, each multi-antimicrobial, per plate (if appropriate)

Test Includes:

Aerobic and anaerobic culture with isolation and identification of isolates. Susceptibility testing will be performed on significant isolates. All positive results are reported immediately by phone to the physician or patient’s nurse.

Logistics

Lab Testing Sections:

Microbiology

Phone Numbers:

Minneapolis:

Saint Paul:

612-813-5866

651-220-6555

Test Availability:

Daily, 24 hours

Turnaround Time:

Preliminary results are available at 24 hours. All positive blood cultures are reported when received. Negative cultures are final at 5 - 7 days.

Special Instructions:

Draw blood before starting antimicrobial therapy. Specific site and date/time of collection are required for specimen processing. Specify organism suspected. If mycobacteria (AFB), viruses or yeast/fungi are suspected, see separate listings.

Specimen

Specimen Type:

Whole blood

Container:

The blood culture set consists of 2 bottles, BACTEC^™ PEDS PLUS/F aerobic medium (pink cap) and PLUS Anaerobic/F medium (orange cap)

Volume:

2 – 6 mL of blood per set; inject 1 – 3 mL into each bottle using the following guidelines:

Weight

Volume per bottle (mL)

<1.5 Kg / 3.3 lb

1.0

1.5 - 3.9 Kg / 8.6 lb

1.0

4.0 - 13.9 Kg / 31 lb

2.0

>14 Kg / >31 lb

3.0

Geisinger Med. Ctr., Danville, PA

Sampling Time:

Draw 2-3 sets of blood cultures per febrile episode at least 60 minutes apart. Do not draw more than 3 sets in a 24-hour period. This provides maximum recovery of microorganisms in patients with intermittent bacteremia, and documentation of persistent bacteremia in patients with intravascular infections (e.g., endocarditis, intravenous catheter site infections).

Collection:

BLOOD:
Venipuncture for patients greater than 26 weeks gestation OR greater than 2 weeks of age:

Prep with ChloraPrep Sepp® Applicator with 2% CHG

1. Remove the protective cap from the bottle, disinfect the stopper of the bottle with 70 % alcohol and allow to dry.
2. Break the Sepp® ampule to release the 2% CHG.
3. Apply the ChloraPrep® solution using a back-and-forth friction scrub for 30 seconds.

4. Allow the area to dry for 30 seconds.
5. If the site must be touched during venipuncture, disinfect the gloved fingers.
6. Collect 2-6 mL of blood per set and aseptically inoculate the bottles using a blood transfer device.

Prep with ChloraScrub™Swab with 3.15% CHG

1. Remove the protective cap from the bottle, disinfect the stopper of the bottle with 70 % alcohol and allow to dry.
2. Open the Chlorascrub™Swab package, do not unfold wipe.
3. Apply the Chlorascrub™ wipe using a back-and-forth friction scrub for 15 seconds.
4. Allow the area to dry for 30 seconds.
5. If the site must be touched during venipuncture, disinfect the gloved fingers.
6. Collect 2-6 mL of blood per set and aseptically inoculate the bottles using a blood transfer device.
7. If <= 1 mL blood is obtained, inoculate only the aerobic (pink) bottle only.

Venipuncture for patients less than 26 weeks gestation AND less than 2 weeks of age:

Prep with 2% tincture of iodine:

1. Remove the protective cap from the bottle, disinfect the stopper of the bottle with 70 % alcohol and allow to dry.
2. Scrub venipuncture site with 70% alcohol for 1 minute using the Frepp® applicator. Allow to dry.
3. Using the Sepp® applicator, apply 2% tincture of iodine to site starting at the center and moving outward in concentric circles. Allow to dry, approximately 30 seconds.
4. If the site must be touched during venipuncture, disinfect the gloved fingers.
5. Collect 2-6 mL of blood per set and aseptically inoculate the bottles using a blood transfer device.
6. If <= 1 mL blood is obtained, inoculate only the aerobic (pink) bottle only.
7. Following collection, remove the iodine using the Frepp® applicator or an alcohol pad.

Line Draw (All ages):

1. Prep catheter port by scrubbing the hub for 30 seconds using chlorhexidine gluconate (CHG) and allowing to dry.
2. Aseptically collect 2-6 mL of blood through the injection port. Blood may be collected without first drawing a discard.
3. Aseptically inoculate the bottles using a blood transfer device.

Transport/Storage:

● Transport to the Microbiology Laboratory immediately at room temperature. Do not refrigerate.
● If cultures become soiled during collection, clean the tip of the bottle using an alcohol pad before transporting.
● If sending bottles through the pneumatic tube system, package bottles separately to avoid breakage.

Sample Rejection:

Specimen with a transit time exceeding 2 hours after collection; specimen not submitted in appropriate transport container; improperly labeled specimen; insufficient volume; external contamination. If an unacceptable specimen is received, the physician or nursing station will be notified and another specimen will be requested before the specimen is discarded.

Interpretive

Reference Range:

No growth

Critical Values:

● Any bacterial isolate should be considered significant and evaluated clinically. All positive results will be called to the physician or patient’s nurse. Susceptibilities will be performed on significant isolates.

● Infection Prevention will be notified with gram stain results that appear to be gram-negative cocci/diplococci.

Limitations:

Factors influencing culture results:

● Volume of blood directly influences recovery rate. A single negative culture does not rule out infection. The likelihood of a false negative result with a single blood culture is approximately 20%. Although a relationship between the volume of blood cultured and detection of pathogens is relevant for low-level bacteremia, the volume of blood removed can be important in children and especially in neonates, whose blood volumes are limited.
● Skin preparation prior to collection is critical to avoid contamination with skin flora. Blood culture contamination (i.e., false-positives) cause substantial negative financial impact that includes laboratory costs, hospital stay, pharmaceutical costs, and associated side effects of inappropriate therapy.
● Yeast often is isolated from routine blood cultures. However, if yeast or fungi are suspected, a separate fungal culture should be drawn. Refer to Blood Culture, Fungus.
● Previous antimicrobial therapy may delay the growth of organisms.
● Other considerations: Patients suspected of having brucellosis, tularemia, leptospirosis, AFB, viruses or cell wall deficient bacteria must be indicated on requisition. These organisms cannot grow in basic media and require special processing or inoculation into specially formulated or supplemented media.

Methodology:

BACTEC^™ 9240 Fluorescent series

References:

Cook, JH, and M Pezzlo (1992). Specimen receipt and accessioning. Section 1. Aerobic bacteriology, 1.2.1-4. In HD Isenberg (ed) Clinical Microbiology Procedures Handbook. American Society for Microbiology, Washington DC

Miller, J Michael (1999) A Guide To Specimen Management in Clinical Microbiology, American Society for Microbiology, Washington DC

Miller, J Michael, and HT Holmes (1999) Specimen Collection, Transport, and Storage In PR Murray et al, (ed), Manual of Clinical Microbiology, 7^th edition, American Society for Microbiology, Washington DC, pp 33-104

Updates:

3/2/2009: Updated collection information for venipuncture options.
3/23/2010: CPT Updates
6/16/2010: Line draw preparation update
3/7/2011: CPT Updates
6/20/2012: Critical Value statement updated