Blood Cultures

Blood Culture Bottle Selection

Blood culture bottles should be selected based on the patient's age.  The following table lists the types of bottles and collection volumes:

 AGE   

BOTTLES 

VOLUME 

NOTES 

>14y

One Set consists of:  1 Green - Aerobic & 1 Orange - Anaerobic

10 mL each bottle

Collect 2 sets from 2 separate sites.
Collect green bottle first.

>3mo., <14y
Large Children

Yellow - Pedi-BacT & Orange - Anaerobic

4 mL in yellow (minimum 3 mL) & 10 mL in orange (minimum 3 mL)

One set is collected.
Collect yellow bottle first.

>3 mo., <14y
Small Children

Yellow - Pedi-BacT & Orange - Anaerobic

3 ml in each bottle (minimum 1.5 mL in each)

One set is collected.
Collect yellow bottle first.

<3 mo.

 Yellow - Pedi-BacT

1.5 mL blood

One bottle is collected.

 

 

 

 aerobic

(green)

anaerobic

(orange) 

pediatric only
aerobic
(yellow) 

Collection Procedure

Adult collection requires two sets of blood cultures drawn with each set consisting of 1 green aerobic bottle and 1 orange anaerobic bottle, for a total of 4 bottles per patient.  Each set of two requires a separate venipuncture site.

Prepare st Set of Blood Culture Bottles

  • Draw a line on each blood culture bottle to indicate fill line.  This is very important, as the bottles will draw more than 10 mL resulting in false negative results.

Cleanse Venipuncture Site

  • Cleanse the site with 70% isopropyl alcohol using a circular motion starting at the centre of the site and working outwards.
  • Cleanse for a minimum of 30 seconds and let air-dry.
  • Cleanse the site with 10% PVP iodine using a circular motion starting at the centre of the site and working outwards.  Cleanse for a minimum of 30 seconds and let air-dry.
     

Disinfect Bottle Tops

  • Cleanse tops of bottles with 70% isopropyl alcohol and let air-dry.
  • Do not use iodine.
  • Disinfect gloved finger if re-palpation of venipuncture site is required in order to prevent contamination of specimen.

Collect First Set of Blood Culture Bottles

  • Using a butterfly needle, fill the green bottle up to the fill line drawn on the bottle.
  • Once the bottle reaches the fill line, fill the orange bottle up to the fill line drawn on the bottle.
  • Ensure bottles are in an upright position at all times when filling. 

Label Blood Culture Bottles

  • Ensure both bottles are labelled with the minimum patient identifiers.
  • If both sets of blood culture bottles are being sent to the lab in one bag, ensure each bottle is also labelled with "number 1" for the first set and "number 2" for the second set.

Mix Bottles

  • Gently mix bottles to prevent clotting. 

Collect 2nd Set of Blood Culture Bottles

  • Repeat the above steps for the second set of blood culture bottles. 

Considerations

  • If drawing blood from an IV, lock, or other type of line, only 1 set of cultures may be drawn from this line.  The second set must be drawn by venipuncture.
  • Always collect the green bottle first.  Do not use yellow Pedi-BacT bottles for adults.
  • If collecting above an IV site, a discard tube must be collected prior to drawing blood culture bottles.  Wipe the tube stopper with alcohol before filling to ensure needle stays sterile.
  • Collect the blood culture bottles first before collecting other blood work.
  • Avoid placing labels over the bottle bar codes.
  • Always check the bottom of the blood culture bottles before proceeding with the collection.  If the bottom of a bottle is yellow in colour, do not use that bottle.  A yellow colour can be an indication that the bottle is contaminated.
    Never     collect all 4 bottles from the same venipuncture.
  • Write the volume collected in each bottle on the requisition, especially if you have a bottle with less than optimum volume of specimen collected.

Over Filling

  • The vacuum in the bottle will exceed the desired draw amount.  Therefore, it is important to watch the volume going into the bottles and make sure they do not overfill.  Overfilling can lead to false negative results. 

Under Filling

  • If unable to collect the optimal amount, try to place the maximum amount in the first bottle (green for adults and yellow for children) and then place as much as possible in the second bottle.