Skip to main content

Carbon Monoxide

Alias: COHb

Discipline: Clinical Chemistry

Test information: Carbon monoxide (CO) poisoning is the most common form of unintentional poisoning.
CO induces toxic effects by tightly binding to haemoglobin to form carboxyhaemoglobin (COHb) and reducing the oxygen carrying capacity of red blood cells. It also interferes with cellular respiration by binding to mitochondrial cytochrome oxidase.
CO poisoning may be misdiagnosed as an acute self-limited illness because its early symptoms are nonspecific (headache, dizziness, weakness, and confusion).
The diagnosis is confirmed by detecting increased COHb % saturation in either venous or arterial blood.

Specimen Type(s)
  • Blood;
Other Acceptable Specimen Type(s)
Specimen Container - Adult
  • Green Top BD;
Specimen Container - Paediatric
  • Light Green Top Microtainer BD;
  • N/A;
Part of a test profile?
Volume (min) of sample to be sent to laboratory
Patient Preparation, Sample Handling and Transport
Maximum add on time
24 hours
Units and Reference Ranges / Interpretation
Smokers upto 6%
UKAS number
UKAS accredited test?
Blood gas measurements include COHb

If you have any queries about a test or results interpretation please contact us.

Last updated: 03-05-2024