In This Section

Available Tests

  • Blood Gas, Venous

Blood Gas, Venous

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

Specimen Type

Test ID LAB79
EPIC Order
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 kit; PLEASE SPECIFY source; See important comments
30 mins
Refrigerated - 1 hr
Frozen - NO
Availability Routine: 24 Hours/Day
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 will not be accepted.
If temperature-corrected results are required, see test
LAB5300 (Blood Gas, Venous 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.

Reference Ranges: Blood Gases
Reference Range Critical Range
pH 7.32-7.43 <7.20 or >7.65
pCO2 40-60 mmHg <20 or >65 mmHg
pO2 30-55 mmHg (at R.A.)
HCO3 22-27 mmol/L
BB ±2 mmol/L
O2 Sat 40-85%

Reviewed by jcayless on December 11, 2019

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