Carbon monoxide poisoning a long-term killer

A new study says that even when people survive a toxic encounter with carbon monoxide,the damaged heart muscle leaves them at risk of death years later.

Despite a decline in the annual death rate, carbon monoxide remains the most common type of accidental poisoning in the United States, with 40,000 emergency department visits made each year because of the effects of the colorless, odorless gas.

Carbon monoxide poisoning can happen with abnormal exposure to gases from any type of combustion, including furnaces and automobiles.

Most victims believe that the one-time exposure to carbon monoxide, would immediately result in problems but in fact the problems may appear much further down the line.

The researchers say that heart injury due to carbon monoxide poisoning increases long-term risk of death.

Christopher R. Henry, B.S., of the Minneapolis Heart Institute Foundation, and colleagues, found that of 230 patients treated for moderate to severe carbon monoxide poisoning, 37 percent suffered heart muscle injury, and almost a quarter died within the next seven years.

According to Henry, the key result of the study is the long-term effect of carbon monoxide poisoning.

He says the fact that almost 40 percent of patients had heart damage related to the carbon monoxide poisoning was much higher than expected.

The Centers for Disease Control and Prevention reported that from 1968 through 1998 carbon monoxide poisoning contributed to an average of 1,091 unintentional deaths and 2,385 suicidal deaths in the U.S. annually.

Symptoms of carbon monoxide poisoning include weakness, nausea, dizziness, lethargy, confusion and headache.

The report recommends that victims be screened for heart damage and that more study be done on the risks they face.

The report is published in this week's Journal of the American Medical Association.