Minimise Blood Culture Contamination-DO’s & DON’Ts

1.1 DON’T’s

  • DO NOT draw blood for culture from groin area when other sites are available
  • DO NOT draw blood for culture from vascular access device unless the patient is suspected of having Central line-associated bloodstream infection (CLABSI)
1.2 DO’s
  • Timing for Blood Culture: Before the administration of antimicrobial agents as far as possible.
  • Skin Disinfection Time: Wait for disinfectants to action & AIR DRY before venipuncture.
First Choice:
2% Chlorhexidine solution in 70% alcohol OR SoluPrep Swab (For at least 30 seconds)
Second Choice:
First apply Povidone-iodine solution, then 70% alcohol solution (For 1.5 to 2 minutes + 30 seconds = 2 to 2.5 minutes

Prepare Blood Sampling Equipment

Prepare Blood Culture Bottles
3.1 Types of Blood Culture Bottles

For Adults:
BACTEC Plus Aerobic/F + BACTEC Lytic/10 Anaerobic/F —> 8-10ml
For Paediatrics:
BACTEC Peds Plus/F —> 1-3ml

3.2 Check & Prepare Bottles
3.2.1 Do not use expired bottles, and those show signs of damage or contaminated, e.g. cracks, excessive cloudiness, and bulging or indented septums. 突出或凹入的隔膜

3.2.2 Remove plastic “flip-off cap” from culture bottles

4. Recommended Blood Volumes
4.1 For Adult Cases: Use BACTEC Plus Aerobic/F & BACTEC Lytic/10 Anaerobic/F culture bottles, recommended volume are 8 to 10 ml for each bottle.
4.2. For Paediatric Cases: Use BACTEC Peds Plus/F culture bottle, recommended volume are 1 to 3 ml.
4.3 DO NOT Overfills Bottles: It may cause a false positive reading
  • (Vacuum is inside the bottle but it will not draw the optimal amount. Rather, if allowed, it will fill to the top). For best volume control, mark fill level on side of bottle prior to collection
5. Identify Patient
5.1 Confirm Patient’s Identity.
5.2 Bottle labelling: Affix the specimen label on the blood culture bottles. DO NOT place label over barcode label or the lot number of the bottles. Stick GCRS label longitudinally. If using Microbiology Request Form, mark the date and time of collection on request form. Label the culture bottles with patient’s name and ID number.

6. Identify Vein
6.1 Identify Vein: Observe for phlebotomy restriction such as warning sign “NO VENIPUNCTURE: for particular limbs or sites. Apple tourniquet, palpate to identify the vein. Clean the site with 70% alcohol swab.

7. Disinfection
7.1 Disinfect Bottles’ Septum: Disinfect the septum by using 70% alcohol swab. Use a fresh swab for each bottle. Allow bottle tops to air dry.
7.2 Skin disinfection:
7.2.1 1st Choice: 2% Chlorhexidine solution in 70% alcohol or SoluPrep Swab: Contraindication: children less than 2 months of age, or patients with known allergies to Chlorhexidine gluconate or alcohol.
  • Dry Sites: e.g. arm, apply 2% Chlorhexidine solution in 70% alcohol or SoluPrep Swab from inner to outer area 5-7cm for 30 seconds.
  • Moist Sites: e.g. inguinal fold, apply 2% Chlorhexidine solution in 70% alcohol or SoluPrep Swab for 2 minutes. ALLOW AIR DRY BEFORE VENIPUNCTURE.
7.2.2  2nd Choice: Alcohol & Povidone-iodine solution: Contraindication: patients with known allergies to iodine or alcohol.
  • Use aseptic technique. Scrub the selected site with Povidone-iodine solution for 1.5 to 2 minutes. Then apply with 70% alcohol for 30 seconds. ALLOW AIR DRY BEFORE VENIPUNCTURE.
  • For neonates especially premature babies: Apply Povidone-iodine solution for 1.5 to 2 minutes. ALLOW AIR DRY. Remove iodine solution with sterile water or saline solution before venipuncture.