- The Washington Times - Tuesday, December 31, 2002

There's a quiet revolution taking place in hospitals and doctors' offices: More and more are getting rid of blood-pressure cuffs that for a century have been the standard, in favor of newer models that don't contain the environmental pollutant mercury.
But these new devices may not be as reliable, some specialists say, and even a small discrepancy could cause mistaken diagnoses that could harm thousands of people.
These specialists want hospitals to hold off replacing all their mercury-containing cuffs until such concerns are settled.
"What we're cautioning against is not overreacting to the environmental concerns and giving up accuracy," says Dr. Daniel W. Jones of the American Heart Association, which is pushing for quick research. "We just don't know how good many of the replacements are."
On the other side of the debate are about two dozen hospitals that have replaced mercury-containing cuffs as part of a broader government-industry effort to virtually eliminate mercury in hospital waste by 2005.
Led by the Mayo Clinic, proponents of the new models say they can work as well as the old ones if they are tested every few months to make sure they're not wearing out.
The new gauges have more parts than the mercury versions, "so they are subject to more wear and tear," says Dr. Vincent Canzanello. His three-year study of Mayo's new type, called aneroid cuffs, found only a 1 percent failure rate, thanks to good maintenance.
Any hospital can run the maintenance checks, says Dr. Canzanello, who is working with the National Institutes of Health to post Mayo's cuff-testing program on the Internet so other hospitals can copy it.
It's not clear how many doctors even know maintenance is necessary, much less perform it.
Dr. Clarence Grim of the Medical College of Wisconsin surveyed Green Bay doctors who were using aneroid cuffs and found one-third were reading blood pressure too low, by an average of six points. In the worst case, one obstetrician's aneroid cuff was 30 points off.
"There's no law that says you have to inspect your blood-pressure device every six months," says Dr. Grim, who'd like to see such a rule. "That just leaves the public open to severe problems because of bad blood-pressure measurement."
Even critics say blood-pressure cuffs are a tiny contributor to mercury pollution. Hospitals use many mercury-containing devices. On the rare occasions when a blood-pressure cuff breaks, the spilled mercury is supposed to be recycled. But that's expensive Mayo spent $26,000 on spills in two years.
Still, the heart association advises hospitals to keep a few mercury cuffs on hand until it can determine the best alternative.
Considering these risks is a balancing act for health workers across the country, who check blood pressure 1 million times a day.
"We can't just be interested in blood pressure and stick our head in the sand and pollute the environment," says Dr. Ed Roccella of the NIH, which has replaced most of its mercury gauges.
Still, he keeps a mercury cuff in his own office, one of several that NIH doctors can use for maintenance checks of their newer models.
And the doctors' debate draws attention to a bigger issue: Harried health workers frequently measure blood pressure incorrectly regardless of which device they use.
Anything from a patient's legs swinging off the exam table feet should be flat on the floor to a too-fast check can throw off the results. Dr. Grim and Dr. Roccella advise people to ask for another check if the first one seems wrong.
One in five Americans has high blood pressure. To measure blood pressure, a cuff is inflated to stop blood flow in the arm's main artery.
When the cuff is deflated, pressure from the resuming blood flow is measured by one of the following:
A gauge containing mercury.
A gauge containing a metal, springlike device instead of mercury. The most popular alternative to mercury, the aneroid devices are considered highly accurate if properly maintained.
An automated device using electronic waves to calculate the pressure. They're not reliable in patients with irregular heartbeats or stiff arteries, Dr. Roccella says. But those made to national manufacturing standards are useful when patients need continual care, or for easy at-home use.

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