Comparing noninvasive blood pressure monitoring technologies: the challenge of between-arm differences.

Continuous noninvasive blood pressure monitoring technologies are increasingly being evaluated against invasive arterial pressure measurements. Berkholz and colleagues demonstrate that a finger-cuff system satisfies International Organization for Standardization (ISO) performance criteria for mean arterial and diastolic blood pressure, although not for systolic blood pressure, and it appeared to show closer agreement with invasive monitoring than oscillometric measurements. However, because oscillometric measurements were necessarily obtained from the contralateral arm, physiological inter-arm blood pressure differences may have contributed to the observed differences in agreement with the invasive reference standard. In this editorial, we describe how the study supports mean arterial pressure monitoring with a finger-cuff system and why it does not establish superiority over conventional oscillometric monitoring.