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Test Code ABGS Blood Gases, Arterial, LAB76


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 arterial 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 minutes.

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: 34-45 mm Hg

Females: 31-42 mm Hg
pO2: 80-90 mm Hg
Critical values

0-23 months: <50 mm Hg or >300 mm Hg

≥2 years: <50 mm Hg or >200 mm Hg

HCO3: 22-26 mmol/L

Males: 24-30 mm Hg

Females: 21-30 mm Hg

Base excess: -2 to +2 mmol/L
% O2 saturation: 94-97%

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. 

Arterial blood is the specimen of choice when evaluating the body's respiratory system.