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Test Code VBG Blood Gases, Venous, LAB79


Ion-Selective Electrode (ISE)

Includes pH, pCO2, pO2, bicarbonate (HCO3), CO2, base excess, and % O2 saturation.

Performing Laboratory

St. Luke's Hospital Cedar Rapids

Specimen Requirements


Preferred: Heparinized syringe with venous blood.

Acceptable: Dark Green Heparinized tube (must be full)

Specimen Volume:150 uL of heparinized blood

Stability: Samples should be placed in ice water if they cannot be run within 30 min.

Collection Instructions: Specimen must be kept as anaerobic as possible.

Reference Values

pH: 7.35-7.45 units
Critical values

0-30 days: <7.2 units or >7.5 units

≥1 month: <7.2 units or >7.6 units

Males: 36-50 mm Hg

Females: 34-48 mm Hg
pO2: 30-50 mm Hg
HCO3: 25-28 mmol/L

Males: 26-31 mm Hg

Females: 24-29 mm Hg

Base excess: -2 to +2 mmol/L
% O2 saturation: 50-70%

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding


Useful For

Blood gas analyses are usually performed for the assessment of either the acid-base status or the respiratory oxygenation status of the patient.