Blood Gases

BC0049

Synonym(s):
Specimen Container
Adult and paed: Heparinised syringe
Neonates: Heparinised capillary tube
Specimen Requirement

Arterial blood sampling should be done at the radial artery in adults unless contraindicated. Before puncturing the radial artery, Allen's test should be performed to assess the adequacy of ulnar blood supply to the same hand and digits. A positive Allen's test means the ulnar blood supply is adequate and therefore the radial artery can be sampled. A negative Allen's test means that another limb is needed for arterial blood sampling. 


Click here for more details on Allen's test.


Collect 2 mL of blood in a heparinised syringe. Expel air bubbles, cap the syringe and roll the specimen between the hands for 15 seconds to gently mix it. Place this in a biohazard specimen bag and then immerse this bag into another bag with crushed ice. Send immediately to Lab. Clotted specimen or air bubble in the specimen will be REJECTED.


Invert blood 5 times after blood collection ensures the anticoagulant is well mixed with the blood. This will ensure results are reliable.

Specimen Storage/Transport
Collect blood in a syringe. Place syringe in a biohazard specimen bag and then immerse this bag into another bag with crushed ice. Send immediately to Lab. 
Orderable as Urgent? Yes
Turn Around Time
Average 30 mins ( 25 - 35 mins )
Reference Value(s)
Adult:
-pH: 7.35 - 7.45 pH units (pH: Reference interval for pH in Arterial blood: 7.35 to 7.45 ; Venous blood : 7.32 to 7.43) 
-pCO2: 35 - 45 mmHg  (pCO2: Reference interval is for arterial blood.) 
-pO2: 80 - 100 mmHg (pO2: Reference interval is for arterial blood.) 
-BE: -2 - 2 mmol/L
-O2ST: 95 - 100 %
-HCO3: 18 - 23 mmol/L
-Ionised Ca: Refer to Test Name 'Calcium, Ionised'
Testing Laboratory Location KKH
Laboratory Clinical Chemistry
Contact Number 6394 1383
Day and Time Performed
Daily, 24 hrs
Orderable on CPOE? Yes
Downtime Form

Clinical Chemistry - Form A

Additional Information
Critical Results:
-pH: Low: <7.2 and High: >7.6
-pCO2: Low: <20 mmHg and High: >50 mmHg
-pO2: Low: <40 mmHg and High: >150 mmHg

Change History Notes

  • 11 Jul 2023 10:00 AM

    ​Update for Specimen storage and transport. 


  • 16 May 2023 03:00 PM


    Update on Specimen requirement for Allen's test.

  • 19 Oct 2021 02:10 PM

    ​Updated Specimen Requirement.

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Last Updated - 05 Apr 2025