The symptoms of carbon monoxide poisoning are so similar to those of the flu, it can be difficult to spot, writes SYLVIA THOMPSON
THE DEATH of Miriam Reidy last week of suspected carbon monoxide poisoning in a Co Cork hotel has brought into sharp focus the threat of this odourless, colourless and tasteless gas, which is sometimes dubbed the silent killer because inhaling it can result in death in rare cases.
That up to five other guests staying at the same hotel as Reidy showed similar sets of symptoms in the same 24 hours has led to much speculation as to why carbon monoxide poisoning was not quickly considered to be the cause of their illnesses.
“If there is an outbreak of illness at a hotel, you think it could be the flu, a gastric bug or food poisoning,” says Dr Mel Bates, the spokesman for the Irish College of General Practitioners.
According to Dr Bates, a diagnosis of carbon monoxide poisoning would rarely be considered, principally because the symptoms patients show are so similar to those linked to a range of viral and bacterial infections that are much more common than carbon monoxide poisoning.
Dr Bates says he has never come across a case of carbon monoxide poisoning so far in his career as a doctor. “It’s difficult to diagnose because it mimics a lot of other illnesses and it happens so extremely rarely that the average GP won’t have come across it in their working lives,” he says.
Carbon monoxide poisoning is caused by the inhalation of carbon monoxide, which is produced when fuels such as gas, oil, coal or wood do not burn fully.
When a fire burns in an enclosed room, the oxygen in the room is gradually used up and replaced with carbon dioxide. Following a build-up of carbon dioxide in the air, the fuel is prevented from burning fully and it starts to release carbon monoxide.
Carbon monoxide is most likely to leak from incorrectly installed, poorly maintained or poorly ventilated cooking and heating appliances.
Symptoms of carbon monoxide poisoning include headaches, tiredness, drowsiness, dizziness, shortness of breath and chest pains. They may also include confusion, irritability, nausea, impaired judgment and, in rare cases, loss of consciousness.
A blood test is the only accurate way to test the levels of carbon monoxide in the blood to confirm whether carbon monoxide poisoning is the cause of the symptoms.
The key difference between these symptoms and those of an infection is that generally, they start to disappear within hours of leaving the room in which the carbon monoxide is present. This means a leak of carbon monoxide poses a higher danger to those who are sleeping or intoxicated because the fumes can reach fatal levels before they realise there is a problem.
When you breathe in carbon monoxide, it enters the bloodstream and mixes with haemoglobin (part of the red blood cells that carry oxygen around the body to vital organs and cell tissues) to form carboxyhaemoglobin. This causes blood vessels to leak which can ultimately lead to brain swelling, unconsciousness and nerve damage.
The response to any suspected exposure to carbon monoxide is to get into fresh air immediately and seek medical care.
Treatment involves the replacement of carbon monoxide with oxygen as quickly as possible. This is often done via an oxygen mask placed over the nose and mouth.
Ultimately, prevention is the best solution and the installation of carbon monoxide detectors in public and private buildings would offer reassurance to all. In some countries, these are compulsory. Some suggest a combined smoke and carbon monoxide alarm would be a useful invention. However, as with smoke alarms, the battery would need to be checked regularly.
Annual maintenance checks on all heating and cooking alliances would be the best way to prevent further deaths from this gas.
More information from carbonmonoxide.ie and poisons.ie