A misplaced arm position can skew blood pressure readings (Will Stone on NPR, Oct 2024)
(from NPR) “Think back to the last time you had your blood pressure taken. How were you sitting? Where exactly was the cuff? And what specifically was your arm doing? It’s such a familiar ritual of going to the doctor’s office that most of us scarcely think about the ins and outs, but in reality, even small missteps can leave you with an inaccurate reading. Research has shown that this can happen for all kinds of reasons. The cuff size may be incorrect. A patient’s legs are crossed or dangling from the exam table. Simply the stress of being in the clinic — what’s known as “white coat hypertension,” can spike the numbers.
Now add to the list a relatively common faux pas: holding your arm in the wrong position.
A trial from researchers at Johns Hopkins University found that simply deviating from the guidelines for arm position can produce an overestimate of a patient’s blood pressure. The inflated readings might be substantial enough to even lead to a misdiagnosis of hypertension and decisions to start medication, says Dr. Tammy Brady, a professor of pediatrics at Johns Hopkins University School of Medicine and senior author of the study, which was published in JAMA Internal Medicine on Monday. “People take blood pressure screening for granted,” says Brady, “but a lot of decisions are made based on what that reading is on the device.”
In the trial, more than 130 adults had their blood pressure measured in three different scenarios, all using an automated device.
The first scenario stuck to the guidelines: Their arm was supported, in this case resting on a desk, with the cuff positioned at about heart level on their arm. The other two scenarios, however, strayed from the protocol in ways that Brady sees quite often in clinical practice, with the arm either resting on the patient’s lap or hanging at their side. Both positions produced substantial overestimates of blood pressure.
