Give blood pressure its due with accuracy

Getting it right the first time

Today, it’s not uncommon for people to get their blood pressure readings at the grocery store while they’re waiting to get a pound of shaved ham, or at the local pharmacy while waiting for a prescription refill. It seems a few quarters and a few minutes are all it takes.

The truth is far from it, however, and as those in the home care field are well aware, there are myriad variables that can affect a reading’s accuracy.

A recent article in the the Journal of Clinical Hypertension written by Raymond R. Townsend, MD, director of the renal-electrolyte and hypertension division at the University of Pennsylvania Medical Center in Philadelphia, cited his finding that it’s not only laypeople who are taking false readings.

"I have been impressed with how often a home blood pressure is poorly done, even by very intelligent people whom I had assumed knew better," Townsend writes.

As such, he shares these tips for getting the best and most accurate blood pressure readings possible:

Take five.

A "quick" blood pressure read with virtually no time of rest, he says, won’t yield accurate data. Instead, he reminds health care practitioners that patients need to sit for at least five minutes with their back and feet supported. He recommends reminding patients who take their own blood pressure at home that their blood pressure will reflect their most recent activity unless the body is given at least five minutes to properly rest.

Third time’s the charm.

Townsend says when it comes to frequency, he recommends that patients take their blood pressure three times a week (once in the morning, once in the evening, and once in the afternoon) for the best overview.

Write it down.

"Patients with atrial fibrillation or other rhythm problems may not tell their physician that it took a dozen tries to get a single reading other than error,’ which makes the obtained data questionable at best," Townsend writes.

To help verify the quality of the data, he advises his patients to use a spiral notebook and enter their readings and other vital statistics (date, time, positions: sitting, standing, etc.) at the time they take their blood pressure. He also requests that they separate the heart rate from the diastolic value. "It is worth the few minutes it takes during a visit to ask the patient to tell you exactly how they take their blood pressures at home. Correcting faults in technique early on, and periodically checking the home monitors against a mercury-based cuff to ensure proper calibration can result in a well-trained patient who takes an active part in their blood pressure management," Townsend notes.

[For more information, contact:

Raymond Townsend, MD, Renal-Electrolyte and Hypertension Division, 210 White Building, University of Pennsylvania Medical Center, 3400 Spruce St., Philadelphia, PA 19104. Telephone: (800) 789-PENN.]

Recommended reading

Townsend R. Journal of Clinical Hypertension 2000; 2(4):288-289.