New cuffs may be less accurate in measuring blood pressure

Tuesday, December 31, 2002

WASHINGTON -- 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.

They 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," said 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 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.

Has more parts

Led by the Mayo Clinic, proponents of the new models say they can work just 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 version, "so they are subject to more wear and tear," said 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 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 unclear how many doctors even know maintenance is necessary, much less perform it.

The doctors' debate draws attention to a bigger issue: Harried health workers frequently measure blood pressure incorrectly regardless of which machine 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.

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