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Carbon monoxide poisoning - Management
When should I suspect carbon monoxide poisoning?

  • Always consider carbon monoxide poisoning as a cause of symptoms, particularly if more than one member of a household (including pets) is affected. Carbon monoxide poisoning can easily be mistaken for a flu-like illness, food poisoning, or depression.
  • Suspect carbon monoxide poisoning when:
    • Clinical features of poisoning are present, and
    • Exposure to a potential source of carbon monoxide has occurred, particularly if
    • Symptoms correlate with exposure.
  • Clinical features
    • With lower level carbon monoxide poisoning the person has no abnormal physical signs and has mild symptoms, including:
      • Headache.
      • Nausea.
      • Poor concentration/memory.
      • Subjective weakness.
    • With higher level carbon monoxide poisoning the above symptoms are more severe and are associated with:
      • The appearance of intoxication or a personality change.
      • An impaired mini mental-state examination.
      • Vertigo and ataxia.
      • Breathlessness and tachycardia.
      • Chest pain (due to angina or myocardial infarction).
      • Loss of consciousness (with very high levels of carbon monoxide, this may be followed by death within a few minutes).
      • Seizure or multiple seizures.
      • Abnormal neurological signs. A wide range of neurological abnormalities may occur including structural damage to the brain, blindness, deafness, and extrapyramidal effects. In people surviving severe carbon monoxide poisoning, the onset of neurological deterioration may be delayed by several days. Memory impairment and changes in personality may persist long term.
  • Potential sources of carbon monoxide poisoning
    • Oil, gas, or solid fuel burnt for domestic heating or cooking, particularly if:
      • The appliance has not been serviced regularly.
      • The appliance is producing fumes or bad odours or there is excessive condensation in the room.
      • Soot or stains have developed around the appliance.
      • There is a yellow or orange, instead of a blue, flame from a gas appliance or boiler pilot light. This does not apply to 'decorative' flame fires.
      • The pilot light goes out frequently.
    • Smoke in burning buildings.
    • Petrol or diesel engine exhaust gases retained in an enclosed space, for example from vehicles or portable generators.
    • Burnt gases from gas or solid fuel appliances intended for outdoor use only, such as charcoal barbecues or camping stoves.
  • Correlation of symptoms and exposure
    • Symptoms develop following exposure and improve slowly when exposure stops.
    • Other people exposed to the same possible source develop similar symptoms correlating with exposure.

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