Medical practitioners guidance on diagnosis and treatment of CO in patients

Medical awareness on CO

The Interim Chief Medical Officer and Chief Nursing Office November 2010 letter to General Practitioners in England brings together the most up-to-date information on CO poisoning:

PL/CMO/2010/02, PL/CNO/2010/02: Carbon monoxide poisoning: needless deaths, unnecessary injury

The letter updates the CMO/CNO letter of November 2008. It describes the signs and symptoms which should be looked for; explains the investigations which may be necessary to establish whether CO poisoning has occurred; describes how cases should be managed; sets out the main sources of CO in the home and gives sources of further advice and information. A copy of a diagnostic tool developed by the Health Protection Agency, Department of Health, Royal College of General Practitioners and College of Emergency medicine is attached to the letter.

• Recognising the symptoms of CO poisoning is not easy.  The most common - headache, nausea and vomiting, tiredness - are also symptoms of a number of other conditions such as food poisoning, flu, migraine or depression.  Patients who present with these symptoms should be asked key questions to identify whether CO poisoning may be the cause.
• Tests to check for CO poisoning include measuring the levels of the gas in expired air and the levels of carboxyhaemoglobin in venous blood.
• Remove patient and relatives from the source of exposure.  In addition, the patient should be provided with an increased inspired concentration of oxygen.  In many cases, providing 100% oxygen using a well-fitting mask is adequate.  In severe cases of poisoning, and in cases involving pregnant women, doctors should consider using hyperbaric oxygen.

• Find out more about this letter

Leaflet on carbon monoxide

• Carbon Monoxide. Are you at risk?
  A NHS information leaflet for patients and the public is available giving guidance on preventing CO poisoning and what to do if they suspect they have been poisoned.