Automated Blood Pressure Measurement of Systolic Hypertension Is More Accurate than Manual Measurement and Helps to Overcome White Coat Hypertension in Primary Care Physicians’ Offices — a Finding with Potentially Significant Impact on Medical Practice

© 2011 Peter Free

 

07 March 2011

 

 

Pay attention to how medical staff take your blood pressure — their protocol is almost always wrong — and that means you might be put on medications that you do not need

 

Over the years, with the pharmaceutical industry’s self-interested drive to get anyone with even marginally elevated blood pressure onto medication, I have noticed a parallel, well-intended, response from a significant proportion of medical providers.

 

Two concealed problems arose:

 

First, most medical offices violate proper blood pressure measurement protocol (which is actually a more mechanically and temporally complex procedure than most people assume).

 

Second (and compounding the first), many patients suffer from “white coat hypertension.”  Our blood pressure goes up when someone is looming over us in an often fast-moving, anxiety-provoking situation.

 

(For example, being an ex-cop, I don’t like someone invading my personal space and latching onto my arm.  I suspect that many people feel the same way.)

 

These two problems probably contribute to the issuance of unnecessary prescriptions for anti-hypertensive drugs.

 

Canadian researchers, writing in the British Medical Journal, said of these two problems:

 

Despite intensive efforts to promote proper techniques for the measurement of blood pressure, widespread concern about the quality and accuracy of blood pressure measurement in “real life” clinical settings continues.

 

Studies from routine clinical practice often report imprecise and inconsistent manual office blood pressure readings owing to poor measurement technique, patient-physician interaction such as conversation during readings, and failure to minimise patient related factors such as anxiety.

 

Recent studies suggest that an accurate office blood pressure reading requires at least 14 minutes, including a period of rest before the first measurement.

 

The likelihood of such careful adherence to protocols for blood pressure measurement in routine, community based, office practice would seem to be low.

 

© 2011 Martin G. Myers et al., Conventional versus automated measurement of blood pressure in primary care patients with systolic hypertension: randomised parallel design controlled trial, British Medical Journal [BMJ], doi: 10.1136/bmj.d286 (7 February 2011) (footnotes omitted, paragraph split)

 

Notice, here, that proper blood pressure measurement requires rest and takes at least 14 minutes.  What busy medical office has time to invest medical personnel for that duration of time into what is usually conceptually regarded as a simple measurement?

 

 

Ways around the blood pressure mis-measurement problem

 

According to Professor Myers, some experts have proposed emphasizing home measurements and 24-hour ambulatory monitoring.

 

The advantage to the home and monitoring procedures are that they eliminate white coat hypertension (and therefore unnecessary medication), and they are probably more reliable predictors of cardiovascular illness.

 

The research team noted that in-office blood pressure measurement problems can also be reduced by automating the process.  Automated, professional-use sphygmomanometers reduce some of the protocol errors involved with manual cuffs.

 

Automated cuffs also permit the patient to rest alone in a quiet room, without medical staff being present to stimulate anxiety.

 

 

The results of in-office automated blood pressure measurement

 

The question for the research team was, in essence, how much of difference would in-office automated blood pressure measurement make?

 

After studying a total of 555 patients with systolic hypertension (303 patients from 36 medical practices in the automation group, and 252 patients from 31 medical practices in the manual measurement group), the team concluded:

 

The introduction of automated office blood pressure into routine clinical practice could be thus expected to decrease systolic blood pressure readings by at least 5 mm Hg and probably by 9 to 13 mm Hg depending on the population of patients.

 

© 2011 Martin G. Myers et al., Conventional versus automated measurement of blood pressure in primary care patients with systolic hypertension: randomised parallel design controlled trial, British Medical Journal [BMJ], doi: 10.1136/bmj.d286 (7 February 2011) (from the Discussion section)

 

 

That’s a potentially significant finding — and it is one patients need to be aware of

 

Long ago, I began carrying copies of my home-monitored blood pressure measurements to physicians’ offices.  (You can do the same with either a manual cuff or an automated home device.)

 

I am averse to being encouraged to take medications that I don’t need.