clinical features

Last reviewed 02/2023

Features of toxicity include:

  • headache 90%
  • vertigo 50%
  • nausea and vomiting 50%
  • alteration in consciousness 30%
  • subjective weakness 20%

Other features of exposure to high concentrations of carbon monoxide may include:

  • confusion
  • cardiac - tachyarrhythmias, myocardial ischaemia
  • neurologic deficits such as hemi- and monoplegia, cerebellar signs, parkinsonism, akinetic mutism, coma
  • cherry red skin colour produced when COHb concentrations exceed 20% is rarely seen in life.

Exposure to lower concentrations of carbon monoxide may lead to the symptoms and signs of food poisoning and influenza (1).

Concomitant cyanide poisoning should be excluded especially in survivors of, e.g. house fires.

Reference:

  • 1. PL/CMO/2008/8, PL/CNO/2008/8: Recognising Carbon Monoxide Poisoning – 'Think CO'
  • 2. PL/CMO/98/5, PL/CNO/98/8 Carbon Monoxide: the Forgotten Killer.