Carbon monoxide is a colorless, odorless gas from fires, faulty heaters, generators and car exhaust that binds to hemoglobin much more tightly than oxygen. It starves the brain and heart of oxygen, and several people in one home with headaches is a classic clue.
Key symptoms
- Headache, dizziness and nausea
- Fatigue, confusion or flu-like illness without fever
- Chest pain or shortness of breath
- Fainting, seizures or coma in severe cases
What you find on exam
- Scene safety: leave the area and use a CO detector
- Level of consciousness and a neurological exam
- Heart rate, blood pressure and breathing
- Normal pulse oximetry does not rule it out; cherry-red skin is rare
Tests
- Carboxyhemoglobin level by CO-oximetry or blood gas
- ECG and troponin for heart injury
- Pregnancy test in women of childbearing age
- Lactate; cyanide level if smoke from a fire
Treatment basics
- Remove the patient from the source
- High-flow 100 percent oxygen by non-rebreather mask
- Ventilation support and airway control if needed
- Hyperbaric oxygen for coma, seizures, pregnancy or very high levels
- Check other people in the home and the heating source
Red flags
- Loss of consciousness or seizures
- Chest pain, ECG changes or a raised troponin
- Pregnancy
Practice it in Making Synapses
Making Synapses cases
Related guides
Sources: NASEMSO National Model EMS Clinical Guidelines; National EMS Education Standards (2021). Written by Making Synapses. Making Synapses is not affiliated with these organizations.