BLOOD GASES

Lab Section Category	Clinical Biochemistry View write-up
Specimen Required	3 mL arterial blood in heparinised sealed syringe immersed in crushed ice. Precaution: Ensure that there is no air space in the syringe and air bubbles present in the syringe are expelled. Tightly seal the syringe nozzle to avoid exposing collected blood to air. The syringe should be gently rotated between the palms of the hands to ensure good mix of blood and heparin. The specimen should then be clearly labelled, placed in a biohazard bag and immersed in another bag with crushed ice and despatched immediately to the laboratory.
Storage/Transport	Keep cold with ice and send immediately to the laboratory.
Method	Electrochemistry
Reference Interval / Value	From 0 day pH : 7.350 - 7.450 pCO2 : 35.0 - 45.0 mmHg pO2 : 75.0 - 100 mmHg Standard Base Excess : -2.0 - 2.0 mmol/L O2 Sat : 95.0 - 100.0% Actual Bicarbonate : 21.0 - 27.0 mmol/L
Turnaround Time	Mean = 4 hrs, Range: 3 – 5 hrs
Day(s) Test Set up	Daily, 24 hrs STAT

Change History Notes

31 Jul 2024 09:00 AM

Reference Interval field is updated on 31 Jul 2024:
"Base Excess" has been replaced with "Standard Base Excess";
"Standard Bicarbonate" has been replaced with "Actual Bicarbonate".
02 Apr 2020 05:05 PM

Specimen Required, and Storage and Transport are updated on 02 Apr 2020.

Last Updated - 13 Jun 2025