Health professionals must put accidental carbon monoxide (CO) poisoning back on their radar when talking to patients with relevant symptoms or risk sending them home to a potentially fatal environment, according to a Perspective published in the Medical Journal of Australia.
Dr Barbara Robertson, from Albury Wodonga Health's anaesthetics department, and coauthor wrote that the symptoms of CO poisoning - headaches, malaise, nausea, dizziness - are non-specific, vague and difficult to diagnose in a general practice setting.
"Further questioning should elucidate whether the symptoms are occurring in other members of the household (including pets), and whether the patient feels better when outside the house", the authors wrote.
"At highest risk are older people, patients with comorbidities, children, pregnant women and their unborn babies."
"The diagnosis of CO poisoning is based on history and examination, in conjunction with an elevated carboxyhaemoglobin level determined using pulse CO-oximetry, arterial blood gas analysis or CO breath testing", the authors wrote.
One of the diagnostic challenges is that the half-life of CO in the blood is 4 hours when the patient is breathing room air (less once high-flow oxygen is commenced) and "the level may have fallen significantly by the time of testing".
The authors explained that CO binds strongly with haemoglobin, preventing the efficient transport of oxygen and its use in the tissues, which can lead to organ damage.
"The treatment of CO poisoning involves immediately removing the patient from the source and instituting high-flow oxygen", the authors wrote.
"The patient should be transferred to an emergency department for full investigation and for consideration of hyperbaric oxygen therapy."
To prevent CO poisoning in the home, the authors recommended that doctors advise patients to use accredited professionals to install gas appliances and service them every 2 years to avoid gas leaks; never to tamper with air vents on gas heaters or use external gas heaters in enclosed areas; to install a CO alarm in the house; and to learn how to recognise CO poisoning.