Cuff Under Pressure for Greater Accuracy

Abstract

Purpose of ReviewTo present the evidence that describes what is being measured by upper-arm cuff blood pressure (BP) and the level of accuracy compared with invasive central aortic and brachial BP. Potential causes of inaccuracy and emerging methods are also discussed. Recent FindingsOn average cuff systolic BP systematically underestimates invasive brachial systolic BP, although in a given individual it may substantially under-or over-estimate central aortic systolic BP. Such errors may affect individual health management outcomes and distort population level data on hypertension prevalence and control.Oscillometric cuff BP is particularly susceptible to inaccuracy in people with high arterial stiffness and with pathophysiological BP waveform shapes. Emerging cuffless BP methods will be susceptible to inaccuracy if oscillometric cuff BP is used for calibration. SummaryThe original purpose of cuff BP was to estimate central aortic BP. Recent evidence has shown substantial inaccuracy of oscillometric cuff BP exists for the measurement of invasive central aortic and brachial BP. Thus, development of more accurate BP methods, through better understanding of oscillometric and BP waveform morphology, is needed to improve health outcomes related to high BP.

Comparison between cuff-based and invasive systolic blood pressure amplification

“…As an example, two people with similar peripheral (brachial) SBP may have vastly different central SBP due to different levels of SBP amplification. In this situation, the person with higher central SBP has theoretically greater cardiovascular risk but this cannot be discerned using standard cuff measurement methods [10,22,23]. Despite this, few clinical trials have to date attempted to assess the implications of this theory using targeted central BP management [24,25], nor confirmed in large trials with hard clinical outcomes.…”

Textbook of Arterial Stiffness and Pulsatile Hemodynamics in Health and Disease

“…Thus, the underlying tenet of accurate BP measurement is to determine the pressure loading and consequent vascular risk at the central arterial beds. 4 This measurement has been coined "central BP," as distinct from standard upper arm cuff BP and represents BP at the ascending aorta. 5 The upper arm is the nearest site at which a cuff can safely be inflated to perform mercury auscultation, and even though this is distal to the central arterial beds, the technique can provide a reasonable determination of an individual's true intra-arterial central BP.…”