Getting the recommended treatment for severe carbon-monoxide poisoning depends on where you live in Canada and who your doctor is, warn the country's specialists in hyperbaric medicine.
Putting a patient suffering from serious exposure to carbon monoxide inside a hyperbaric oxygen chamber is a recognized treatment for swiftly decreasing the amount of the gas in a person's system.
But only 10 hospitals in Canada have hyperbaric units, all located in major cities. The unit in St. John's, N.L., has been shut down since February because of staffing problems.
And a study to be published in Canadian Family Physician in January will suggest that an understanding of the uses of hyperbaric medicine is spotty among doctors in Canada.
Study co-author Dr. Ted Sosiak, one of Canada's few specialists in the area, said the chances someone living outside major cities would get access to the treatment is low.
Toronto General Hospital, where Sosiak often works, is the only one in Ontario to provide on-call emergency use of its chambers.
"Most physicians don't have the knowledge of hyperbaric medicine and there's also just this one facility right now providing on-call coverage 24 hours a day," said Sosiak.
Hyperbaric chambers are right out of a science fiction movie -- long cylindrical chambers that resemble a spaceship's escape pod. Patients go for "dives" as the chamber simulates the pressure of going underwater.
The theory behind hyperbaric treatment for carbon monoxide, or CO, poisoning is two-fold.
One, it expels harmful CO more quickly from the body with the blast of oxygen.
Two, it can theoretically stop processes in the body that continue to inflict damage to brain cells and other areas even after the carbon monoxide is gone. A 2002 study in the New England Journal of Medicine suggested that providing the therapy to victims reduced the incidence of serious brain damage.
"It's been more clearly understood now that you're actually using hyperbaric oxygen to stop a bunch of damaging chemical processes which the carbon monoxide starts," said Dr. Wayne Evans, founding chairman of the Ontario Medical Association's section on hyperbaric medicine.
Evans says he treats more than 100 people a year in the chambers for severe carbon-monoxide poisoning. The chambers are most often used to treat patients with diabetic ulcers or radiation wounds.
Still, there's debate in the medical community about whether the chamber has any better effect on patients than oxygen administered with a mask.
A 2005 review of the body of literature on treating carbon monoxide through hyperbaric oxygen therapy suggested there is no solid evidence it is any more effective in curtailing brain damage than simply giving a person oxygen the regular route.
Dr. Andrew Worster of McMaster University's faculty of medicine, a co-author of the study, said until research shows that another treatment works better or that hyperbaric chambers are actually harmful, the practice of prescribing oxygen therapy will continue.
Doctors are "faced with someone who has a very serious problem, and it's very hard for the physicians to sit there and do nothing," said Worster. "They would quite often rather do something, even if that something is ineffective."
Sosiak says Canadians need to realize that preventing poisoning in the first place is the bottom line.
"This stuff can be so utterly devastating," said Sosiak.
"I've seen people with personalities of lizards because it has a nasty predilection for knocking off the neo-cortex, from the outer part of the brain, and it can yield devastating consequences."
