Carbon Dioxide (CO2 Content)
Label Mnemonic: CO2
Epic Lab Code: LAB55
Order Form: Laboratory Requisition
Collection Medium:
Plasma Separator Tube 4.5 mL
Alternate Collection Media:
Call laboratory for additional acceptable specimen collection containers.
3 mL whole blood from light green top tube or ONE Microtainer® for pediatric patients
Testing Schedule:
24 hrs/day, 7 days a week, including holidays.
Turn Around Time:
1 hour (upon receipt in laboratory)
Reference Range:
13 years and older: 22-29 mEq/L
0-12 years old: 18-27 mEq/L
Cord blood: 15-20 mEq/L

Critical value: <10 mEq/L and >50 mEq/L
This test measures bicarbonate + dissolved CO2.
Test Limitations:
Plasma Icterus: No significant interference up to an I index of 60 (approximate conjugated and unconjugated bilirubin concentration: 60 mg/dL). Hemolysis: Significant negative interference at an H index greater than 600. Lipemia (Intralipid): Significant negative interference at an L index greater than 1800 (approximate triglycerides concentration: 3600 mg/dL). There is poor correlation between turbidity and triglycerides concentration.
Sample Processing:
Centrifuge at 3000 RPM for 10 minutes.
Aliquot plasma into labeled container and cap.
Sample Storage:
Transport Instructions:
Place specimen into zip-lock type bag, seal bag.
Place requisition into outside pocket of bag.
Transport in cooler with refrigerated coolant packs.
CPT Code:
See also:
Carbon Dioxide (CO2 Content)-Other, Body Fluid
See Additional Information:
Chemistry Critical Lab Values