Carbon Monoxide Poisoning (http://biology.about.com/library/weekly/aa062200a.htm)

Dateline: 06/22/00
Sources: University of Toronto and ScienceDaily
Scientists at the Toronto General Hospital announced an effective and simple way of "speeding up" the removal of carbon monoxide from the body. The treatment can be applied by paramedics even before a patient arrives at a hospital. Information from the original news release about the study is reported below.
-- A new treatment for carbon monoxide poisoning may save thousands of lives around the world. This treatment helps victims of carbon monoxide (CO) exposure eliminate the poison from their bodies faster than the current treatment. In a paper published in the American Journal of Respiratory and Critical Care Medicine, Toronto General Hospital researchers describe a simple new way of speeding up the elimination of carbon monoxide, which can be applied by paramedics even while en route to a hospital.
"Carbon monoxide is the leading cause of fatal poisoning in the industrialized world, as well as being endemic in many parts of the developing world," says Dr. Joseph Fisher, an anesthesiologist at Toronto General Hospital, University Health Network. "In North America, it results in as many as 70,000 emergency room visits a year and in thousands of deaths. Up to 30 per cent of survivors of severe poisoning are left with disabling psychological and neurological symptoms, which sometimes last for years."
Carbon monoxide is an odorless colorless gas formed during combustion. When carbon monoxide is inhaled--even in tiny concentrations--it combines with the hemoglobin in the red blood cells to prevent the delivery of oxygen to the body. This results in few symptoms until the poisoning is advanced. Those suffering from carbon monoxide poisoning may initially complain of headache, nausea and fatigue but the symptoms can rapidly progress to coma and even death. It is therefore critical that carbon monoxide be eliminated from the body as soon and as quickly as possible.
The only currently available emergency treatment for carbon monoxide poisoning is giving the patient 100 per cent oxygen. "We developed a device that greatly increases the rate of carbon monoxide elimination compared to the current treatment, yet is very easy to apply to patients no matter where they are," says Dr. Fisher, who is also Assistant Professor of Medicine at University of Toronto. The device is easily portable, and consists of a few simple additions to the oxygen mask and oxygen tank found in every ambulance. When treating CO poisoning, oxygen is administered via a standard facemask placed on a patient. However, Dr. Fisher and his team found that adding a simple mechanical device which provides a mixture of oxygen and carbon dioxide in a specific way to the mask markedly increases the rate of carbon monoxide elimination. "The device is so simple that it can be assembled from a few components available in any SCUBA diving store" says Dr. Fisher.
The novel treatment has been compared to conventional treatment with 100 per cent oxygen in seven men who volunteered for the study. The volunteers were first exposed briefly to carbon monoxide and then received either the conventional treatment or the new treatment. They then returned for a second session and were treated with the other treatment and the rates of carbon monoxide elimination were then compared. The new treatment increased the rate of carbon monoxide elimination by up to three times. Dr. Fisher's team has since confirmed these results with additional tests. A study from the University of Washington in Seattle presented last month at the American Thoracic Society conference in Toronto also confirmed the efficacy of the method.
"We are still at an early stage, but since the technology is so simple and inexpensive to implement, and there are no foreseeable side effects, we hope that it can quickly become available to firefighters and paramedics as well as physicians for the emergency treatment of carbon monoxide poisoning" says Dr. Fisher. (More information is available on Dr. Fisher's laboratory website: isocapnia.com.)
Toronto General Hospital is a partner in the University Health Network, along with the Toronto Western Hospital and the Princess Margaret Hospital. Building on the strengths and reputations of each of these remarkable hospitals, the University Health Network brings together the talent, resources, technology and skills that make it an international leader in health care, research and teaching.