Carbon Monoxide Poisoning

Key points

• CO: binds haemoglobin with ~240× oxygen affinity → carboxyhaemoglobin → tissue hypoxia.
• Features: headache (often household/seasonal pattern), confusion, cherry-red skin (rare), normal SpO₂ on pulse oximetry.
• Diagnose: carboxyhaemoglobin level (arterial/venous blood gas co-oximetry).
• Management: 100% oxygen via tight-fitting mask until COHb normal.
• Hyperbaric oxygen considered if COHb > 25%, neurological features, pregnancy, or myocardial ischaemia.

Decision points in this pathway

• COHb > 25% · neuro features · pregnancy · myocardial ischaemia?

The full step-by-step algorithm, including what to do at each branch, opens in the app for approved members.