Inaccuracies introduced by single width blood pressure cuffs

Abstract

Blood pressure (BP) cuff dimensions directly affects accuracy of BP measurements. For accurate BP measurements the width of the cuff must be proportional to arm circumference. A cuff that is too narrow results in falsely high BP values, and a cuff that is too wide results in falsely low values. Some BP standards permit a single cuff regardless of arm circumference.The purpose of this study was to evaluate whether 12 cm single width cuffs currently permitted by the British Hypertension Society (BHS) standard are sufficiently accurate.Each of 101 subjects was tested sequentially with both a single and a proportional width cuff in random order. Auscultatory BP was determined by 2 observers using a double binaural stethoscope.The single width cuff BP failed the Association for the Advancement of Medical Instrumentation and BHS standards for clinically acceptable accuracy. The magnitude of failures ranged from a mean of 6.6 to 11.3 mmHg.In conclusion, this could result in a significant number of people being misdiagnosed and mistreated for hypertension. Therefore, to avoid “cuff hypertension” and “cuff hypotension”, the cuff width should be proportional to arm circumference.