Test Name
CO2
Specimen Type & Acceptability
Serum
5 days refrigerated
(CO2 is only acceptable for 5 days if it is in an unopened, refrigerated SST)
General Use
Screening for acid-base balance in a patient.
High value can indicate respiratory acidosis with CO2 retention, or metabolic alkalosis (eg, prolonged vomiting).
Low value may indicate respiratory alkalosis as in hyperventilation or metabolic acidosis (eg, diabetes with ketoacidosis).
CPT Code(s)
82374
Special Instructions
Let clot for 10-20 minutes. After the sample is fully clotted, centrifuge the sample. Verify complete separation between cells and serum. DO NOT OPEN TUBE and refrigerate.
Container/Tube Type
Volume
0.5 mL Min. vol. = 100 ul
Suggested Tube Types
Description
Typical Volume
Gold Top Serum Separator Tube (SST)
⋜ 5 mL
Tiger Top Serum Separator Tube (SST)
^For larger volume tests
> 5 mL
Red Top Tube (No additive)
⋜ 5 mL
EDTA Whole Blood
3 mL
3.2 % Sodium Citrate Whole Blood
2.7 mL
Lithium Heparin Plasma Separator Tube
⋜ 5 mL