Blood culture samples are collected for culture set-up using sterile technique to reduce the chance of contamination.
II. Clinical Significance:
A blood culture is valuable in detecting the presence of organisms in the blood, in establishing the phase of infection, in determining the effectiveness of antibiotic treatment and in assessing the prognosis of the patient.
1. Timing and Number:
A. Optimal times for the collection of blood cultures:
a. As soon as possible after the onset of fever or chills.
b. Whenever serious infection is suspected.
B. Most cases of bacteremia are detected by using two to three sets of separately collected blood cultures drawn in the initial 24 hour period of onset. More than three sets of blood cultures yield little additional information. Conversely, a single blood culture may miss intermittently occurring bacteremia and make it difficult to interpret the clinical significance of certain isolated organisms.
C. The ideal time interval between blood collections is 30 - 60 minutes. However, in medically urgent situations, in which antibiotic therapy is to be started immediately in the critically ill patient, two separate blood culture specimens are collected within a few minutes and then antibiotic therapy is started. When two or more specimens are collected within a few minutes, these collections are made separately and taken from different arms.
2. Volume of blood
The volume of blood is critical because the concentration of organisms in most cases of bacteremia is low, especially if the patient is on antimicrobial therapy. In infants and children, the concentration of organisms during bacteremia is higher than in adults, so less blood is required for culture.
Note: The preferred collection method is to use a winged blood collection device and inoculate blood directly into the blood culture bottle(s).
A. Adult routine draw:
When SPS yellow-topped vacutainer tubes are used; 8.3 ml of blood is collected into each tube. When blood is inoculated directly into the BacT/Alert bottles, a winged blood collection device is used, and 8-10 ml is collected into each bottle (BacT/Alert FA FAN Aerobic and BacT/Alert SN Standard Anaerobic).
B. Adult difficult draw:
Draw 3-10 ml of blood with a syringe and using a Saf-T Holder, inoculate only the BacT/Alert FA FAN Aerobic bottle. A winged blood collection device may also be used.
C. Pediatric and Nursery routine draw:
Use the following table to determine the recommended volume of blood and placement of blood drawn from nursery and pediatric patients.
A. If a Fungus only blood culture is ordered; using a winged blood collection device, collect blood in two separate BacT/Alert FA FAN Aerobic bottles.
B. If a Fungus culture is ordered in addition to a routine culture, no special handling is required and the specimens are collected and handled as outlined in III.2.A.
C. A separate order for a Fungus Blood Culture is requested in the LIS.
D. If Histoplasmosis is suspected, a heparin tube is also drawn. The blood from this tube is plated directly onto fungal media.
4. Mycobacteria culture or Mycobacterium avium intracellularae (MAI) requested:
Draw 1 Yellow top SPS 10 ml Vacutainer® tube. Send the tube to Cathedral Square Microbiology with the requisition for Acid-fast Culture.
B. Bone Marrow:
Prior to the bone marrow procedure, prep the top of the yellow-top vacutainer tube with an alcohol wipe. Using a sterile needle and syringe, remove approximately half of the liquid from the tube. Immediately after marrow aspiration, remove the tube stopper and dispense a portion of the aspirate into the tube. Send the tube to Cathedral Square Microbiology Dept with a requisition for an Acid Fast Culture.
C. Grossly Bloody Body Fluid:
Send 1-5 ml of the sterile fluid in a sterile container to Cathedral Square Microbiology Dept with a requisition.
Total Circulating Blood Volume
Recommended Volume of Drawn Blood for Blood Culture
≤ 2.2 lbs
Draw one culture (not the recommended 2). Draw 2 ml of blood into a pediatric blood culture bottle.
Draw two separate blood cultures from two venipuncture sites (as recommended). Draw 2 ml from the first venipuncture into a pediatric bottle. Draw 2 ml from the second venipuncture into a pediatric bottle for the second culture draw.
> 200 ml
Draw two separate blood cultures from two venipuncture sites (as recommended). Draw 4 ml into the first pediatric bottle. Draw 2 ml from the second venipuncture into a pediatric bottle for the second culture draw.
> 800 ml
Draw two separate blood cultures from two venipuncture sites (as recommended). Draw 5 ml from each venipuncture site into pediatric bottles.
> 80 lbs
> 2,200 ml
Draw as an adult. Use the adult blood culture bottles.
1. BacT/Alert blood culture bottles:
The BacT/Alert vials are ready for use as received and require no reconstitution or dilution. Store in a cool, dry place (2 - 25°C), out of direct sunlight. Do not use vials past their expiration date. Prior to use, examine the vials for evidence of damage or deterioration. Do not use vials displaying turbidity, contamination, or discoloration (yellow or orange on the bottom of the bottle). If an inoculated vial leaks or spills, treat the leak or spill with caution, pathogenic organisms may be present. Refer to “Spills, Biological” in the “Engineering and Workplace Practice Controls” section of the Exposure Control Plan for cleanup and handling instructions.
A. BacT/Alert FA FAN Aerobic (BioMerieux #BM-259791)
100/case; supplemented with pyridoxine and hemin with activated charcoal.
B. BacT/Alert SN Standard Anaerobic (BioMerieux #BM-259790)
100/case; 0.035% SPS and CO2 in Nitrogen.
C. BacT/Alert PF Pediatrics FAN (BioMerieux #BM-259794)
100/ case; supplemented with pyridoxine and hemin with activated charcoal.
2. 70% Isopropyl Alcohol Wipes (CardinalHealth #40000-090)
3. 2% Tincture of Iodine Sepp Applicator (CardinalHealth #B3063-83)
4. ChloraPrep Single Swabstick (CardinalHealth #MF260100)
5. SPS (Sodium-Polyanetholesulfonate) yellow top vacutainer tubes (CardinalHealth #B3006-54)
6. Saf-T Holder device with male luer (Smith’s Medical #96004) 50/case
7. Saf-T Holder device with female luer (Smith’s Medical #96005) 50/case
8. Refer to the “Venipuncture” procedure for supplies related to blood collection.
V. Reagents: N.A.
VI. Standardization: N.A.
A. Observe Universal Precautions. Refer to the “Venipuncture” procedure for policies regarding glove usage and hand washing.
B. Assemble the venipuncture set immediately prior to preparing the patient.
Note: A Vacutainer® system, sterile syringe or winged blood collection device, may be used to collect the specimen. If multiple specimens are required, the same venipuncture site may be used, however, the blood cultures are drawn first. When using the winged blood collection device, insert the adapter into the Saf-T Holder device with male luer after drawing the cultures, if additional specimens are needed.
C. Tube preparation:
a. Prepare the SPS Vacutainer® tubes by wiping off the top of the tubes with 2% tincture of iodine.
b. Prepare BacT/Alert bottles by wiping off the top with 70% isopropyl alcohol. Do not use iodine.
D. Apply the tourniquet and select the site for venipuncture. Avoid drawing blood through indwelling intravenous or intra-arterial catheters unless blood can’t be obtained by venipuncture. Refer also to the “Venipuncture” procedure for the site selection process. After the site has been selected, remove the tourniquet.
E. Open a ChloraPrep applicator package and remove the sterile swab. Care must be taken to have the package facing away from the patient while opening it, to avoid splashing or spraying of extra liquid onto the patient. Thoroughly cleanse the site for a full 30 seconds using a continuous back-and-forth/up-and-down friction scrub. Cover approximately a 3 inch area on the skin. Allow the area to dry for a full 30 seconds before performing the blood collection. Do not repalpate or touch the venipuncture site after cleansing.
Note: Do not use on infants less than 2 months of age because of the potential for excessive skin irritation and increased drug absorption.
a. Cleanse the venipuncture site with a 70% isopropyl alcohol pad for 30 seconds using an up-and-down/back-and-forth motion.
b. Let dry for 30-60 seconds.
c. Wipe the site again concentrically outward.
d. Again let air dry for 30-60 seconds.
e. Do not touch the site before performing the venipuncture.
f. Do not use on patients with known allergies to chlorhexidine gluconate or isopropyl alcohol.
F. Remove the needle guard and perform the venipuncture.
Blood is routinely collected directly into the blood culture media using a winged blood collection device and a Safe-T Holder device with male luer. Fill the aerobic vial first (as the tubing has air in it). Avoid backflow by keeping the culture bottle lower than the collection site. Do not allow the blood culture media to contact the stopper or needle during collection.
Note: It is not acceptable to use a vacutainer needle and a tube holder assembly and put the BacT/Alert bottle in the tube holder to fill as with other vacutainer tubes. Only SPS vacutainer tubes may be collected in this way, if necessary.
b. Adult-difficult draw
Prepare the BacT/Alert bottles as described in the bottle inoculation section. Collect 3.0 - 10.0 ml of blood with a syringe and then, using a Saf-T Holder device with female luer, immediately inoculate the BacT/Alert FA FAN Aerobic bottle.
c. Pediatric or Nursery
Prepare the BacT/Alert bottles as described in the bottle inoculation section. Collect 2 - 4 ml of blood with a syringe and then, using a Saf-T Holder device with female luer, immediately inoculate the BacT/Alert PF Pediatric FAN bottle.
d. The blood culture bottles have a vacuum, but it is not precisely measured as in other vacutainer tubes. It is important to watch the bottles as they fill or place a mark on the bottles to ensure that enough, but not too much, blood enters the bottle.
G. Mix all tubes by inverting them 4-5 times, after withdrawing them from the needle holder.
H. After bleeding from the puncture site has stopped care for the puncture site according to the “Venipuncture” procedure.
I. Label the SPS vacutainer tubes or blood culture bottles according to the “Specimen Identification” policy.
Note: Do not place the label over the barcode on the side of the blood culture bottle.
J. Transport the SPS vacutainer tubes to the lab as quickly as possible for transfer into the BacT/Alert bottles.
2. Bottle Inoculation from SPS Tubes:
Note: Transfer the specimen in the SPS vacutainer tubes to the BacT/Alert bottles as soon as possible because SPS may inhibit organisms, i.e. Neisseria meningitidis, N. gonorrhoeae, Peptostreptococcus anaerobius, and Gardnerella vaginalis.
A. Remove the caps from the BacT/Alert FA FAN Aerobic and BacT/Alert SN Standard Anaerobic bottles. Wipe off the tops of the bottles and the SPS vacutainer tubes with a 70% isopropyl alcohol wipe and allow to air dry. Do not use iodine.
B. Using a Saf-T Holder device with female luer, withdraw the contents of one SPS vacutainer tube into a 10 ml syringe. Using the Saf-T Holder, transfer the blood into a BacT/Alert FA FAN Aerobic bottle. Using another syringe and Saf-T Holder device with female luer, transfer the contents of the second SPS vacutainer tube to a BacT/Alert SN Standard Anaerobic bottle. Care must be taken not to subject the specimen to any air.
C. Once the appropriate BacT/Alert bottles have been inoculated, label the bottles with the accession number and a patient demographic label.
Note: Do not place the labels over the bar code on the side of the bottle.
3. Bottles are loaded onto the BacT/Alert instrument immediately after blood collection (or inoculation, if needed). Follow the BacT/Alert procedure for placement of the inoculated bottles in the instrument for incubation and monitoring.
Note: MMC-DV: Maintain bottles at room temperature and ship them with the next available courier. Bottles must be loaded on the BacT/ALERT instrument within 24 hours of collection.
4. Spill Clean Up:
Refer to “Spills, Biological” in the “Engineering and Workplace Practice Controls” section of the Exposure Control Plan for clean-up instructions.
VIII. Limitations: N.A.
IX. Results Derivation: N.A.
X. Expected Result(s) and/or Critical Values: N.A.
XI. Quality Control: N.A.
1. Clinical Laboratory Nursing Station Manual, 1984 Edition
2. Barlett, R.C. Ellner, P.D. Washington, J.A. Blood Cultures, Cumitech 1 ASM, October 1974
3. Reller, L. Barth, Blood Cultures, Cumitech 1-A, ASM, June 1982
4. Becton Dickinson Laboratories Bactec Bottles Product Insert
5. Strand, C.L., Bloodstream Infections, ASCP Press, Chicago
6. Hoeltke, Lynn; The Complete Textbook of Phlebotomy; 1994, pp 176-178.
7. Mayo Medical Laboratories Mycology Workshop; November 2004.
8. Ernst, Dennis; Center for Phlebotomy Education; personal communication; February 2005.
9. Cumitech 1B; April, 1997. pp 2-5.
10. Cumitech IV; 1C; January, 2007. p. 4.
12. ChloraPrep.com; Labeled Warnings.
13. BacT/Alert Package insert, July 2008.
i. February 2005 R. Schaefer (Revised: I., III.2., 3.D., IV.7., VII.1.B-K., XII.6-8.)
ii. January 2007 R. Maiers, R. Schaefer (Revised: for BacT/Alert System & use of ChloraPrep)
iii. May 2008 S. Hosch (Revised: VII.3.Note)
iv. July 2008 R. Schaefer (Revised: IV.4.; VII.E.)
v. August 2010 R. Schaefer (Revised: VII.1.E.)
March 2011 R. Schaefer (Revised: VII.1.E.Note.; XII.12.)
July 2011 R. Schaefer (Revised:VII.2.A.; XII.13.)