Clinical starting point
Think through the case
After an enclosed-space fire, a patient has headache and confusion. The conventional pulse oximeter reads 99%. Can this reading exclude carbon monoxide poisoning?
Review the essentials
Open each section, then test your reasoning.
Assess the exposure
Establish the setting, exposure duration, symptoms, and other affected people. Evaluate airway and respiratory injury alongside possible systemic toxic exposures.
Know the measurement limit
Conventional pulse oximetry cannot reliably identify carbon monoxide poisoning. Evaluate carboxyhemoglobin using appropriate co-oximetry; time away from exposure and oxygen treatment affect interpretation.
Treat and escalate
Provide oxygen and assess neurologic and cardiac effects. Consider hyperbaric consultation based on severity and clinical context, including pregnancy. A CO level alone does not determine severity. Smoke exposure can involve additional toxins; seek specialist input when indicated.
Apply what you know
Knowledge check
0 of 3 answered
Source & learning scope
CDC · Clinical guidance for carbon monoxide poisoning ↗
New standalone learning edition · Prepared October 22, 2026. Professional education; apply current guidance and local protocols. This focused lesson is not a complete treatment pathway.