The importance of cuff width in measurement of blood pressure indirectly

Blood pressure was measured indirectly in young adults with arm circumferences ranging from 21 to 35 cm using three standard blood pressure cuffs (thigh, adult, and child). The auscultatory method was used with Phase 1 and Phase V to indicate systolic and diastolic pressures respectively. It was found that use of the narrow cuff provided values higher than those obtained with the adult cuff; use of the thigh cuff produced value lower than those obtained with the adult cuff. These data, and a careful review of the literature, reveal the fundamental nature of the effect of the ratio of cuff width to member circumference with respect to the accuracy of indirect blood pressure measurements. The order of error expected with narrow and wide cuffs is discussed.