Board Review: Carbon Monoxide Poisoning
Carbon Monoxide Poisoning
33 year old healthy female presents to the ED via EMS after she was found unconscious in a burning house. On your initial physical exam the patient is awake but confused. She has normal vital signs with a pulse oximetry of 94%. You suspect carbon monixide poisoning and send labs. What is the minimal carboxyhemoglobin level that hyperbaric oxygen therapy would be indicated for this non-pregnant female? (scroll down for the answer)
The correct answer is D) 25%
A carboxyhemoglobin level >25% is an indication for hyperbaric oxygen therapy for any non-pregnant patient regardless of symptoms.
Carbon Monoxide Pearls
- Colorless, odorless gas
- Peak incidence in fall and winter
- Normal physiologic levels are approximately 1% in nonsmokers but in smokers can reach as high as 10%
- Standard pulse oximetry is unreliable as oxygen saturation readings will be artificially high
- Commonly used indications for hyperbaric oxygen treatment: pregnancy with carboxyhemoglobin level >15%, non-pregnant carboxyhemoglobin level >25%, syncope, evidence of acute myocardial ischemia, altered mental status, seizure, coma, focal neurologic deficit
1 Stapczynski, J. Stephan,, and Judith E. Tintinalli. Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York, N.Y.: McGraw-Hill Education LLC., 2011.