UMEM Educational Pearls

Category: Toxicology

Title: Carbon Monoxide (CO) Poisoning

Keywords: carbon monoxide, CO, hyperbarics, HBO (PubMed Search)

Posted: 12/4/2008 by Ellen Lemkin, MD, PharmD (Updated: 12/6/2022)
Click here to contact Ellen Lemkin, MD, PharmD

CO is formed from the incomplete combustion of carbon materials, eg. fires, stoves, portable heaters CO reversibly binds hemoglobin, producing carboxyhemoglobin (HbCO). This causes oxygen to bind more tightly to hemoglobin, releasing less in the tissues. Because of this, it affects the organs with the highest oxygen requirements most profoundly (eg. brain and heart).

Symptoms are mainly neurological and cardiovascular, but may include a wide variety of non-specific symptoms. The initial symptoms of CO poisoning may include headache and flu-like illness progressing to confusion, agitation, lethargy, seizures and coma.

Place patients on 100% oxygen to decrease the half-life of HbCO. Though controversial, HBO therapy is thought to decrease the incidence of neurologic sequelae. HBO therapy should be considered for patients with a HbCO level above 20%, severely symptomatic patients with lower levels, and pregnant patients. Remember that pulse oximetry will not be accurate.

References

-Poisondex