Geisinger Medical Laboratories Microbiology Specimen Collection Instructions
BLOOD CULTURE COLLECTION
- INDICATIONS
- Blood cultures are indicated for a
sudden relative increase in patient's pulse rate and temperature,
change in sensorium or blood pressure, chills, or prostration.
- Prolonged or intermittent and mild
fever in association with heart murmur is also an appropriate indication.
- In general, any time bacterial, fungal, or mycobacterial sepsis is suspected, with the possible exception of minor mucocutaneous infections or of lower urinary tract infections.
- Blood cultures are indicated for a
sudden relative increase in patient's pulse rate and temperature,
change in sensorium or blood pressure, chills, or prostration.
II. RECOMMENDATIONS
- Obtain cultures prior to initiation of antimicrobial therapy if possible.
- For bacterial or fungal sepsis, two cultures per patient collected by separate venipuncture is the standard in the Geisinger system for all adults and children, except in unusual circumstances (e.g., neonates). For mycobacterial sepsis, three cultures collected on separate days is recommended.
- Numerous studies have been published
regarding both the appropriate volume and numbers of blood cultures.
The consensus of experts is that, except in very unusual cases,
no more than four sets of blood cultures should be collected in
one 24-hour period. If all four sets are negative after 24 hours
and sepsis is still suspected, more cultures may be collected.
- No more than four sets of blood cultures are to be accepted for culture by the laboratory each 24 hours (calendar day) unless approved by the Microbiology doctoral director or Pathology resident on call.
- Separate venipunctures are required for each set of cultures. Exceptions may occur, such as in the case of a patient having poor veins or a bleeding problem. In these cases, the blood cultures may be collected with a single venipuncture; however, this should be avoided if at all possible. In addition, for young pediatric patients, two cultures may be collected from one venipuncture if specifically requested by the attending clinician. The two separate volumes should still be collected as for two separate venipunctures.
- Severe life-threatening septicemia:
Two cultures, taken by separate venipuncture, should be collected
immediately before starting treatment. There is no benefit for
delaying a second venipuncture by 30 minutes when taking two blood
cultures. We require that the blood cultures be obtained in duplicate
from two separate venipunctures at the same sitting; however, as
previously noted, no more than four total cultures should be collected
in a 24-hour period.
- Suspected SBE or low-grade intravascular
infection: Four cultures should be taken within the first 24 hours
at intervals. Timing is not critical. In other situations, timing
is difficult because bacteremia may precede the
onset of fever or chills.
- A larger number of cultures may have
to be collected from persons already receiving antimicrobics. Cultures
should be taken immediately before the next dose of parenteral
antimicrobial agent.
- Infants and small children: Two blood cultures usually are sufficient (one may suffice in the neonate).
III. DESCRIPTION AND OPTIONS
- One blood culture consists of a FAN
(Fastidious Antibiotic Neutralization) aerobic and a FAN anaerobic
bottle. For patients < 13 kg, either one FAN aerobic bottle
or one Pediatric FAN bottle is used (see table).
- FAN aerobic bottle = 30 mL BacT Alert
bottle (green cap).
FAN anaerobic bottle = 40 mL BacT Alert bottle (orange cap).
FAN pediatric bottle = 20 mL BacT Alert bottle (yellow cap) - There are two routine methods of blood
culturing in the Geisinger system:
- Routine blood culture: This is used for culture of both bacteria and yeast: Two BacT Alert bottles (FAN aerobic and FAN anaerobic).
- Isolator
blood cultures (these should be collected by phlebotomists
if possible):
- Routine isolator blood culture needs Infectious Disease (I.D) referral.
- Fungal isolator blood cultures are used for detection of dimorphic fungi (primarily Histoplasma) and may be ordered by an I.D. physician only. Refer to Section V: Collection of Isolator Blood Cultures.
- AFB is cultured using the MB BacT blood culture bottle. If unavailable, collect in SPS or sodium heparin blood collection tube.
- Viral blood cultures: Lavender-top tube containing 7-10 mL of blood (EDTA anticoagulant).
IV. COLLECTION OF ROUTINE BLOOD CULTURES
- Materials needed:
- BacT Alert Blood Culture Bottles – consists of a FAN (Fastidious Antibiotic Neutralizations) aerobic (green) and a FAN anaerobic bottle (orange). For patients <13 kg, one FAN aerobic bottle is used (yellow).
- Chloraprep One-Step Frepp Applicator
- A butterfly apparatus and one Saf-T holder Blood Culture device (CUP)
for each set of cultures or one butterfly and one 20m> syringe for each set. - ChloraPrep Sepp applicator for cleaning the bottle tops.
- Gauze.
B. Procedure for the collection of routine blood cultures:
- Patient Identification - two forms of identification as per proper identification procedure. (If using Collection Manager scan bracelet and print labels at bedside)
- Wash hands and apply gloves
- Apply a tourniquet and palpate arm for suitable vein.
- Release tourniquet.
- Using the Chloraprep One-Step Frepp Applicator, clean the patient's skin by scrubbing up and down and side-to-side. Scrub for 30 seconds. Allow to air dry.
- While drying, prepare the blood culture bottle(s) by cleaning the top of the bottles with Chloraprep Sepp applicator and marking a fill line on the blood culture bottles (10 mL’s each).
- Do not touch the venipuncture site unless your finger has been similarly disinfected.
- Venipuncture using Saf-T HOLDER Blood Culture Device with a Male luer adapter:
- Attach butterfly, perform venipuncture.
- Insert blood culture bottles green (aerobic) first, orange (anaerobic)
- Remove bottles, and insert adaptor for venipuncture tube back in cup; continue drawing tubes with correct order of draw.
- Remove needle, activate safety device and apply pressure to venipuncture site.
- Venipuncture using butterfly and syringe.
- Remove syringe from package. Holding empty syringe, move plunger barrel out and then in as far as possible. This will serve to make it
easier to draw plunger back when actually drawing blood, and remove any excess air from syringe. - Place butterfly apparatus needle on syringe.
- For routine blood cultures, collect 20 mL of blood (if pediatric patient,
volume of blood is determined by patient weight; refer to table. - Remove needle, activating safety device and apply pressure to
venipuncture site. - Without allowing needle to become potentially contaminated by
touching bedding, remove the butterfly needle and replace with the 18 gauge transfer needle, place syringe directly into one blood culture bottle. For routine cultures, distribute 10 mL into each bottle. Inoculate the anaerobic (orange) first, aerobic (green) bottle second.
C. Procedure for blood culture collection from Mediport and Broviac.
- Mediport: Clean and disinfect the skin as for a venipuncture and
proceed to draw blood accordingly. - Broviac:
- Clean the port with a ChloraPrep One-Step FREPP applicator.
- Disinfect the port using 2% tincture of iodine applicator. Do not allow iodine to pool in the stopper.
- Allow iodine to dry for one minute and collect the specimen.
- Write the time of collection, date, type of stick (straight or butterfly) and
your tech code on the requisition form. Blood cultures will not be
accepted by the Microbiology laboratory unless all of this information is
provided
D. Volume of blood to be collected for routine blood cultures:
- Adults: 20 mL of blood should be collected by syringe and equally
divided between each BacT Alert bottle. If this amount cannot be
obtained, a lesser amount may be used and equally divided between
the bottles. (If 5 mL or less is collected, place the entire amount in
the green aerobic bottle.) Notify the laboratory if this occurs by writing
amount collected on the laboratory requisition form. - Pediatrics: Collect as follows:
Total
Volume to Collect
|
Divide
Among the Following
|
|||
FAN
BacT Alert |
FAN BacT Alert (Aerobic) |
FAN BacT Alert (Anaerobic) |
||
| < 1.5 (3.3) | 1.0 |
X |
||
| < 4.0 (8.8) | 1.0 |
X |
||
| 4-13 (8.8-28.6) | 3.0 |
X |
||
| 13-25 (28.6-55.0) | 10.0 |
X |
X |
|
| > 25.0 (55) | 20.0 |
X |
X |
|
Pediatric guidelines were developed in conjunction with pediatric physicians at GMC, following guidelines developed at Mayo Clinic.
- Deliver bottles to the laboratory immediately so that incubation can be initiated. Be sure that the tech code of the phlebotomist is properly located on the label or requisition form. NOTE: Due to the critical importance of these culture results, every effort should be made to deliver inoculated blood culture bottles to Microbiology on the same day they are collected; however, if this is not possible, bottles must be kept at room temperature and delivered to the lab within 24 hours of collection.
V. COLLECTION OF ISOLATOR BLOOD CULTURES
A. This test is available from 0700 to 2300 hours daily. Phlebotomy should be notified by phone (Client Services 800-695-6491) when an Isolator culture (Routine, Blood Culture, or Fungal) is required. These requests must be approved by the Infectious Disease Service.
B. Isolator Specimen Collection
1. General Information: Isolator blood culture tubes will be supplied by Microbiology to phlebotomists when necessary.
- If patient weighs < 13 kg (28.6 lb), use one pediatric Isolator. If patient weighs >13 kg, use two pediatric Isolator tubes.
- Blood should be collected directly into the Isolator tube. To avoid clotting, do not collect via butterfly needle if possible. A butterfly may be used when collecting Isolators when other blood work is ordered. Collect the Isolator first in this case.
- STRICT ASEPTIC TECHNIQUE is necessary for collection.
- CAUTION: Do not allow the contents of the tube to touch the yellow stopper in order to prevent the possibility of back flow of reagents from the tube which may cause an adverse patient reaction.
- CAUTION: The Isolator tube reagent can cause eye irritation if it contacts the eyes. If contact occurs, flush the eyes with water and seek medical attention.
2. Materials Required: Isolator tube - pediatric
ChloraPrep One-Step FREPP
ChloraPrep SEPP
Venipuncture supplies (Vacutainer)3. Collection Procedure (Adult and Pediatric):
- Prepare arm according to procedure for the collection of routine blood cultures (Section IV.B1.-B5).
- Disinfect stopper of the tube with a Chloraprep SEPP Applicator.
- Collect blood using a vacutainer setup. Allow tube to fill completely. The patient’s arm should be lowered so that the tube is lower than the needle to allow for complete fill.
NOTE: Any tubes not completely filled must be approved by Microbiology. Lack of blood volume may cause EDTA toxicity and decrease recovery of some organisms. - Invert the tube 4-5 times to prevent clotting and allow the red blood cells to be lysed.
- Label the tubes and request cards appropriately, making sure to record the time of collection and your tech code on the request card. Do not apply identification stickers to the Isolator tube. Write the patient information on the existing label.
- Transport (hand-carry) to the lab as soon as possible. Use of the pneumatic tube system is NOT allowable as it may cause hairline cracks in the glass, which may lead to breakage during the high-speed centrifugation process used to process these tubes.
4. Rejection Criteria
- Isolator tubes that contain less than a full tube (1.5 mL of blood) may not be processed. Microbiology may reject the specimens depending on the circumstances.
- Extended delay in transport that would not allow processing within 16 hours of collection time will merit rejection.
- Blood Culture Requests (examples of options available)
Test Requested |
May Be Requested By |
Please Collect |
Order and Chart As |
Blood Culture |
Any physician |
BacT Alert Set 1 |
Blood Culture (BLC) or Blood Culture 2 (BLC) |
Isolator Blood Culture2 |
Infectious Disease Service |
2 Pediatric Isolator Tubes 1 |
Blood Culture (BLC) Source: Isolator Blood |
Fungus, Blood, for Histoplasmosis |
Infectious Disease Service |
2 Pediatric Isolator Tubes1 |
Fungus Culture- Blood (FCB) |
AFB Blood Culture |
Any physician |
MB BacT Blood Culture Bottle 1 |
AFB Culture (AFBC) |
1For pediatric patient weighing less than 13 kg (28.6 lb), collect single aerobic BacT Alert or Pediatric Isolator, as appropriate.
2This will usually be ordered along with routine (BacT Alert) Blood Cultures but should be a separate request.
VI. HANDLING OF CULTURES
- Storage of blood culture bottles:
- Nursing units, clinics, and GML clients may store limited amounts of blood culture bottles.
- Store the blood culture bottles in a cabinet in a secure, low-traffic area separate from storage of other nursing items. The outside of the cabinet must be labeled with identification of contents.
- All BacT Alert bottles must be incubated at 35°C upon receipt in the testing
laboratory (the Microbiology Laboratory at GMC).
- Blood cultures are usually incubated for five days. Some organisms such as Brucella and certain streptococci may take longer than five days to grow. Brucella blood cultures are incubated for 21 days. The physician must obtain clearance from the Infectious Disease Department and notify the laboratory if he wants cultures held longer than five days. If approved by the doctoral director of Microbiology, any culture held longer than five days will be held for 21 days.
VII. HANDLING BREAKAGE AND SPILLS OF BLOOD CULTURE BOTTLES.
- Refer to hazardous clean-up procedure (Safety Manual).
- Fill out Employee Accident/Exposure Form.
References:
Baron, Ellen, et al, 2005. Cumitech IC: Blood Cultures IV. American Society for Microbiology, Washington DC.
Biomerieux. Durham, NC. BacT Alert Culture Bottle product insert, September 2003.
Biomerieux. Durham, NC. BacT Alert PF bottle product insert, October 2004.
Wampole Isostat Microbial System, Instructions for use. 2003.
Washington, JA: 1985, p 27. Laboratory Procedures in Clinical Microbiology, 2nd ed. Springer Verlag, Princeton.
Revised: 3/4/2011