"Do I Have to Take Off My Shirt?"

Reading blood pressure on a sleeved arm might be fine, but one expert urges caution.
Measuring blood pressure on a sleeved arm violates long-established guidelines for this procedure, but, in busy clinical settings, it’s done all the time. Does taking the time to extract patients’ arms from their sleeves really make any difference?
Canadian researchers used automatic oscillometric cuffs to obtain two blood pressure measurements — taken 3 minutes apart — in 376 adult medical-clinic patients. In 180, both measurements were performed on unsleeved arms, and, in 196, the second reading was taken on sleeved arms. In both groups, the mean systolic and diastolic values in the second reading were slightly lower than those from the first (as would be expected after more time in a seated position); however, the presence of sleeves resulted in no significant difference in the size of the decrement. In the subset of patients with hypertension, the presence of sleeves was similarly unimportant. The researchers estimated the mean thickness of the sleeves at 4.3 mm, equivalent to that of a shirt or light sweater.
Comment: In several other studies, researchers have concluded that the bare-arm requirement in blood pressure measurement probably is not warranted. But an editorialist says that an immediate guideline change might be premature, because automated devices, such as the one used in this study, were all validated on bare arms, and individual models could lose accuracy at highly variable rates when clothing interferes with oscillometry.
— Abigail Zuger, MD
Published in Journal Watch General Medicine March 13, 2008
Citation(s):
Ma G et al. A comparison of blood pressure measurement over a sleeved arm versus a bare arm. CMAJ 2008 Feb 26; 178:585.