Test ID COHBB Carbon Monoxide, Blood
Useful For
Verifying carbon monoxide toxicity in cases of suspected exposure
Method Name
Carboxyhemoglobin-Co-oximetry
Reporting Name
Carbon Monoxide, BSpecimen Type
Whole Blood EDTAContainer/Tube: Lavender top (EDTA)
Specimen Volume: 1 mL
Collection Instructions: Avoid exposure of specimen to atmosphere.
Specimen Minimum Volume
0.1 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Whole Blood EDTA | Ambient (preferred) | 14 days |
Frozen | 14 days | |
Refrigerated | 14 days |
Clinical Information
Carbon monoxide (CO) poisoning causes anoxia, because CO binds to hemoglobin with an affinity 240 times greater than that of oxygen, thus preventing delivery of oxygen to the tissues. Twenty percent saturation of hemoglobin induces symptoms (headache, fatigue, dizziness, confusion, nausea, vomiting, increased pulse, and respiratory rate). Sixty percent saturation is usually fatal. This concentration is reached when there is 1 part CO per 1,000 parts air.
Carboxyhemoglobin diminishes at a rate of about 15% per hour when the patient is removed from the contaminated environment.
The most common cause of CO toxicity is exposure to automobile exhaust fumes. Significant levels of carboxyhemoglobin can also be observed in heavy smokers. Victims of fires often show elevated levels from inhaling CO generated during combustion. Susceptibility to CO poisoning is increased in anemic persons.
Reference Values
Normal Concentration
Non-Smokers: 0-2%
Smokers: ≤9%
Toxic concentration: ≥20%
Cautions
No significant cautionary statements
Day(s) Performed
Monday through Friday; 12 a.m.
Report Available
Same day/1 dayPerforming Laboratory

Test Classification
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
82375