Blood Gas, Arterial

Includes: pH, pCO2, pO2, Bicarbonate, Base Balance, O2 Sat. (measured)

Specimen Type

Test ID LAB76
CPT Code(s) 82805
Group/Individual Test Group
Laboratory Core Laboratory-Blood Gas
Tube Station 31
Specimen Routine: 1.5 mL whole blood in 3cc syringe w/ lyophilized heparin in BG Kit or SafePICO Collection Kit.
PLEASE SPECIFY: source; See important COMMENTS
Micro: 0.5 mL whole blood in syringe w/ lyophilized heparin in BG Kit or full capillary tube; PLEASE SPECIFY: source; See important comments
Room Temp - 30 mins
Refrigerated - 1 hr
Frozen - NO
Availability Routine: 24 Hours/Day
Turnaround Time 10 minutes
Reference Range Normal: See Table below
Critical: See Table below

Deliver Immediately. The time between specimen collection and analysis should not exceed 30 minutes.
Syringes with needles attached will NOT be accepted
Heparinized capillary samples can be analyzed if at least 200 µL of clot-free blood is present. Blood Gas Syringes may be obtained from Central Distribution. Blood collection tubes are not acceptable.
If temperature-corrected results are required, see test
LAB5301 (Blood Gas, Arterial Temperature Corrected).

Oxygen Saturation is a measure of the fraction of oxygenated hemoglobin in relation to the amount of hemoglobin capable of transporting oxygen. Oxygen Saturation can be clinically misleading in the presence of dyshemoglobins such as carboxyhemoglobin and methemoglobin. This is because the oxygen-carrying capacity of the blood will be decreased but the saturation will often remain within reference limits.

Reflex testing for Carboxyhemoglobin (CPT 82375) and Methemoglobin (CPT 83050) will automatically be performed if 02 gap is > 10.0

Reference Range Critical Range
pH 7.35-7.45 <7.20 or >7.65
pCO2 35-45 mmHg <20 or >65 mmHg
pO2 80-110 mmHg (at R.A.) <40 mmHg (arterial)
HCO3 22-27 mmol/L
BB ±2 mmol/L
O2 Sat 94-100% <75%

Reviewed by jcayless on January 12, 2022

Note: Reference ranges provided on this web site are for guidance only, and may not reflect the most recent changes. Refer to laboratory reports for current reference data.

UNC Hospitals
McLendon Clinical Laboratories
101 Manning Drive
Chapel Hill, NC 27514