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Test Code CO2 Carbon Dioxide (CO2) LAB55

Test Method

Rate pH Change, CO2 Electrodes; Beckman DXC600

Specimen Requirement

0.5 mL serum or plasma is required.

Additional Specimen Collection Information

Collect blood in a lithium heparin, green-top or red-top tube.
PST and SST (gel tubes) are acceptable. Serum or plasma should be
separated from contact with the cells within 2 hours of collection.
Specimens not centrifuged within 4 hours of collection may be
rejected. Refrigerate the specimen if unable to assay within 8
hours of collection. Hemolyzed specimens are not acceptable.
Samples with >3+ lipemia must be cleared prior to analysis.

Reference Values

22-32 meq/L

  • Critical Value:

    • Low: < 10 meq/L
    • High: > 40 meq/L


Testing is performed Monday through Sunday.

Routine: Typically completed within 4 hours after the
specimen arrives at the testing site.

Expedite: Typically completed within 1 hour after the
specimen arrives at the testing site.

STAT: Typically completed within 30 minutes after the specimen
arrives at the testing site.

Useful For

Carbon dioxide levels are important is assessing metabolic
acidosis and hyperventilation.

LOINC Code Information

2028-9 Carbon Dioxide, Total [Moles/Volume] In Serum Or

CPT Code Information

82374 Chemistry: Carbon dioxide (bicarbonate)