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Test Code COHB Carbon Monoxide, Blood

Additional Codes

Epic Code


Performing Laboratory

Bronson Laboratory Services-Chemistry

Reference Values

Nonsmoker: 0.0-2.5%

Smoker: up to 10%

Critical value (automatic call-back): ≥15.0% (If elevated >15.0%,

test is reported on any blood gas specimen that is tested whether carboxyhemoglobin [COHb] is ordered or not.)


Specimen Transport Temperature

Ambient or Refrigerate 7 days

Specimen Requirements

Specimen Type: Whole Blood, Venous or Arterial

Container/Tube: Lithium Heparin ('Green Top' tube)
Optimal Specimen Volume: 4 mL

Minimum Specimen Volume : 0.5 mL whole blood

Collection Instructions: Invert several
times to mix blood. Do not centrifuge.


Spectrophotometry (SP)

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding