Carbon Dioxide

Test Code

CO2

CPT Codes
82374

Preferred Specimen

Serum (gold top) tube

Minimum Volume

0.5 mL

Other Acceptable Specimens

Lithium Heparin Plasma (green top) tube

Transport Container

Serum (gold top) tube or Lithium Heparin Plasma (green top) tube

Transport Temperature

Room Temperature or Refrigeration

Specimen Stability

Room Temperature - 24 hours; Refrigerated - 3 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Quantity Not Sufficient, EDTA (purple top tube) contamination, IV contamination

Methodology
Colorimetric

Setup Schedule

Daily upon receipt

Report Available

Upon completion of analysis

Reference Range

Birth - 1 Month:          17 - 24 mmol/L
1 Month - 2 Years:   20 - 28 mmol/L
2 Years - Adult:        22 - 30 mmol/L

Clinical Significance

The carbonic acid–bicarbonate buffer system is one of the important buffer systems that maintains the pH of the blood. Total CO2 (i.e., bicarbonate plus dissolved CO2) measurements are used together with other clinical and laboratory information (arterial pH and pCO2) for the evaluation of acid-base disorders. Total CO2 is generally increased in respiratory acidosis, metabolic alkalosis, and excessive alkali intake. CO2 is decreased in compensated respiratory alkalosis, metabolic acidosis, and in renal disorders where H+ ions cannot be excreted.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.