The impact of arm circumference on noninvasive oscillometric blood pressure referenced with intra-aortic blood pressure.

Abstract

To investigate the influence of arm circumference (AC) on the brachial blood pressure (BP) measured with an adult cuff. This study included 208 patients (150 men, 61.0±8.0 years) for coronary angiography. Intra-aortic BP and noninvasive right brachial oscillometric BP (noninvasive BP) were measured simultaneously before coronary angiography. The noninvasive BP was measured using an electronic oscillometric device with an adult cuff (12×22 cm). The mid-ACs were measured. Thus, proper cuff-arm (≤26 cm) and small cuff (>26 cm) groups were created. The difference in intra-aortic and noninvasive BP was calculated as BPi-n. The correlation coefficients (r) between noninvasive and invasive systolic blood pressure (SBP), mean artery pressure, and diastolic blood pressure (DBP) were 0.88, 0.76, and 0.58, respectively. The SBPi-n was higher (7.9±1.6 vs. 5.2±1.1 mmHg), but the DBPi-n (3.9±1.4 vs. 6.1±1.0 mmHg, P<0.05) was lower in the group ≤26 cm than in the group >26 cm. Among the four subgroups divided by 20-23, 24-26, 27-30, and 31-37 cm of AC, as the AC increased, the SBPi-n increased, but DBP decreased, resulting in noninvasive SBP 4.6 mmHg higher and noninvasive DBP 4.6 mmHg lower in the 31-37 cm group in comparison with the 20-23 cm group. When an adult cuff was used, the noninvasive oscillometric SBP was overestimated, but DBP was underestimated in the individuals with large arms against the intra-aortic BP.