A Comparison Of Invasive And Non-invasive Blood Pressure Measurements For Determ[ining Arterial Vascular Compliance

ABSTRArn A non-invasive arterial blood pressure waveform monitor was compared to standard brachial artery pressure monitoring for both mean, diastolic and systolic pressure measures and pulse contour derived proximal and distal arterial vascular compliance. The study was performed on 23 cases from 17 individual healthy volunteer subjects. Compliance was calculated from a modified Windkessel model of the peripheral vasculature, utilizing parameters from the pulse contour analysis of simultaneously recorded non-invasive and invasive pressure waveforms. There were no statistically significant differences between any of the paired pressure values. Pressure measures varied by less than 20% between methods for the majority of cases (from 52% of diastolic to 91% of systolic cases). Compliance differences were greater, with systematically higher values for non-invasively derived proximal and distal compliance than those obtained from direct brachial cannulation. This study demonstrated that pulse contour derived compliance can be determined from a non-invasive blood pressure waveform monitor. Studies in our laboratory using noninvasive methodology are comparing compliance in healthy subjects and hypertensive and heart failure patients to see if differences in compliance between these groups can be detected, as has been shown previously using invasive