Pittsburgh, PA – By Anita Srikameswaran, Pittsburgh Post-Gazette

Last summer, Amy Davis took a power washer inside a stable to clean stalls. It was a mistake she won’t make again.

She used the gasoline-powered device in the enclosed space for 40 minutes before taking a break for lunch.

“I didn’t realize until I stopped power washing that anything was wrong,” said Davis, 38, of Ligonier. “That’s when I realized that I was so dizzy [and had a] terrible, horrible headache.”

Her symptoms were those of carbon monoxide, or CO, poisoning. Though usually associated with malfunctioning furnaces during cold weather, CO is a year-round hazard whenever gas-powered devices are used in confined spaces.

So far this summer, four people have been treated for CO poisoning at the University of Pittsburgh Medical Center after using gas-powered devices.

In Davis’ case, landscapers working near the stables called her doctor when her symptoms persisted after getting some fresh air. The doctor sent her to the Latrobe Area Hospital emergency department.

At first, Davis “was sort of clueless,” as she put it, about why she felt ill, but the strong smell of gasoline in the barn was a big hint for her co-workers and doctors.

She was sent by ambulance to the hyperbaric unit at UPMC Presbyterian and during the next 24 hours had three treatments inside the high-oxygen chamber before she was well enough to go home.

“When you’re going to power-wash something, you’re not really reading the directions and the warning labels,” Davis noted. But CO poisoning “can happen so quickly.”

Carbon monoxide poisonings occur more often in the winter when faulty furnaces leak the colorless, odorless gas into homes during heating, said Dr. Kevin O’Toole, director of UPMC’s hyperbaric unit.

“It may be a statistical fluke that we’re seeing more now,” he said.

All the cases treated at UPMC occurred outside Allegheny County. The county and state health departments keep track of CO poisonings; neither agency has noted an unusual number of cases this summer.

According to the U.S. Centers for Disease Control and Prevention, 500 people die annually of accidental CO poisoning and more than 2,000 use it to commit suicide.

Carbon monoxide is deadly because it prevents oxygen from getting to cells and tissues. It binds to hemoglobin far more strongly than oxygen does.

Victims of the poisoning are treated in hyperbaric chambers where a high oxygen level helps displace the carbon monoxide from hemoglobin-containing red blood cells and also directly supplies tissues with the needed gas, O’Toole said.

Poisoning symptoms, which include headache, nausea, dizziness, weakness, chest pain and confusion, can mimic other conditions.

But “just like a [heart attack] or a stroke, time to treatment is really important,” O’Toole said. “People who are treated within six hours of exposure do a lot better than people who are treated later.”

If there is a suspicion of CO contamination, “open the windows [and] turn off the potential source of it,” advised Dr. Peter Kaplan, director of the respiratory diseases division at Allegheny General Hospital. “Certainly get out of the environment. That’s the most important thing.”

The National Institute for Occupational Safety and Health cited cases in which several people were poisoned while using pressure washers in underground parking lots and a plumber got sick using a gasoline-powered concrete saw in a basement with open windows and doors and a fan.

“The misconception is if you keep the windows and doors open that you’re going to be OK, and you’re really not,” O’Toole said.

He said that hoses and other extensions can be used inside, but the engine component should stay outside.