There is an increasing public health concern that new devices that measure blood pressure are poor replacements for the old-fashioned, mercury-gauged cuffs.
"Sometimes these new devices give readings that are very wrong. If we don't know whether we as physicians have an accurate reading, we can't be sure patients are receiving proper -- even safe -- treatments," said Dr. Daniel W. Jones, an internationally known hypertension expert who is high blood pressure spokesman for the American Heart Association (AHA). Jones also is associate vice chancellor for health affairs at the University of Mississippi Medical Center (UMC) in Jackson.
A public health alert about the devices was issued in a joint statement from the AHA, with spokesman Jones, and the National Heart, Lung and Blood Institute (NHLBI) of the National Institutes of Health.
Older, mercury-gauged arm cuff units that were standard equipment (and very accurate) in doctor's offices and hospitals are being replaces with dial or electronic cuffs (much less accurate). The mercury cuffs are disappearing since mercury is a toxic pollutant that needs proper disposal, hospitals and physicians nationwide have been returning mercury-gauged sphygmomanometers to their manufacturers to comply with a 1998 federal waste reduction standard. Unfortunately the newer types of blood pressure units are much more likely to give inaccurate readings with prolonged use or if they have been bumped or dropped. Even new units have been found to be inaccurate.
Inaccurate readings from the non-mercury devices can be as high as 50 (diastolic or systolic) points in some patients, especially the elderly, Jones said. The ramifications may be false diagnosis and, subsequently, improper treatment of patients -- leading to severe problems.
Ensuring Accurate Blood Pressure Readings
- Hospitals and doctors offices need to retain at least one mercury-gauged cuff.
- In order to ensure accuracy of other blood pressure measuring units, those readings need to be verified against a mercury reading. If they are found to be inaccurate the units need to be recalibrated by the manufacturer if necessary.
- Patients using home dial or electronic units should continue to check their own blood pressure but should have the accuracy of those units checked against a mercury reading at the hospital or doctors office.
