Assessment of the Accuracy of Indirect Blood Pressure Measurements.

Abstract

SUMMARYThis study assessed the accuracy of indirect blood pressure (BP) measurements by simultaneously performing three kinds of indirect BP measurement on the left arm (auscultatory, microphone and oscillometric methods) and a direct BP measurement on the left arm. The subjects were 34 hospitalized patients, ranging in age from 18 to 73 years (average 47.5 years). Highly significant correlations in systolic or diastolic BP between a given pair of the three indirect methods. The indirect methods underestimated systolic BP and overestimated diastolic BP compared with the direct method, with differences ofmmHg with the auscultatory method. The difference in systolic BP between the auscultatory and direct methods was greater and the difference in diastolic BP was smaller in subjects older than 50 years than in those aged 50 years or less (p<0.001 for systolic BP, p<0.05 for diastolic BP). The auscultatory method revealed greater systolic BP in subjects with increased carotid arterial wall stiffness assessed by echoarteriography. Thus, it is concluded that there are inherent differences in BP between the indirect and direct methods which can be attributed to the changes in arterial wall physical properties partly due to aging. (Jpn Heart J 1997; 38: 393-407)

Estimation of central systolic blood pressure using an oscillometric blood pressure monitor

“…of 10.5/7.6 mm Hg (SBP/DBP), 9.7/8.9 mm Hg and 8.1/6.5 mm Hg with the oscillometric method, microphone method and the auscultatory method, respectively. 26 In this study, the accuracy of the oscillometric blood pressure monitor was reasonably good as shown by s.d. for SBP/DBP of 7.2/ 6.1 mm Hg at steady state and 9.7/8.1 mm Hg after NTG administration, respectively (Table 2).…”

“…14,24 Large variations between the indirect and direct blood pressure measurements have been well recognized. [25][26][27][28] A previous study assessing the accuracy of indirect blood pressure measurements at steady state clearly showed that the indirect methods underestimated SBP and overestimated DBP compared with the direct method, with s.d. of 10.5/7.6 mm Hg (SBP/DBP), 9.7/8.9 mm Hg and 8.1/6.5 mm Hg with the oscillometric method, microphone method and the auscultatory method, respectively.…”

“…29 Our study reconfirmed that the oscillometric method substantially underestimates brachial SBP and overestimates brachial DBP, while providing reasonably good estimates of the brachial MBP. 14,26,30 Although all current noninvasive methods for the estimation of aortic pressure are affected by the limited accuracy of the oscillometric blood pressure monitors, 31,32 the clinical values of the central blood pressure estimates remain evident. 5,7,8 Because brachial SBP2 represents a very significant weight in both the invasive and noninvasive prediction models, the accurate identification of SBP2 on a peripheral pulse without visible late systolic peak may deserve concerns.…”

Differences in blood pressure values by simultaneous auscultation of Korotkoff sounds inside the cuff and in the antecubital fossa

“…This could prevent the propagation of Korotkoff sounds to the distal auscultation site. This assumption is supported by a study of Ochiai et al, 22 who compared intra-arterially measured blood pressures with those obtained simultaneously by auscultation in the cubital fossa. They found that as well the systolic and the diastolic differences between both methods (auscultation-invasive) were positively correlated to the subject's age, probably due to fading compressibility of the arteries with increasing age.…”

A silent revolution in blood pressure measurement? Some late remarks in regards to the HOT study

“…(3) When testing the automatic devices, the relevant characteristics of the patients included in the trial, such as their age [6][7][8] and range of blood pressure, 9 must be representative.…”