Carboxyhemoglobin, COHb

This is a blood test used to determine carbon monoxide poisoning. It measures the amount of serum COHb, which is formed when the hemoglobin (oxygen carrying part of the blood) combines with carbon monoxide.

PREPARATION FOR TEST

No preparation or fasting is necessary.

NORMAL FINDINGS

  • Adults: <2.3% (0.023)

  • Adult smokers: 2.1% - 4.2% (0.021 - 0.042)

  • Adult heavy smokers (more than 2 packs/day): 8% - 9% (0.08 - 0.09)

  • Hemolytic anemia: Up to 4%

  • Newborn: greater than 12%

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.

MEANING OF TEST

Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.

OBTAINING THE TEST RESULTS

It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.