Noninvasive Blood Pressure Measurement in Maintenance Hemodialysis Patients: Comparison of Agreement between Oscillometric and Finger-Cuff Methods

Abstract

Background: The Nexfin monitor is a device used for measuring arterial blood pressure (BP) continuously and noninvasively through finger-cuff technology. Since it was validated against the auscultatory method using a sphygmomanometer, the aim of this study was to test the ability of the Nexfin to evaluate brachial arterial pressure (BAP) in maintenance hemodialysis patients, quantifying accuracy and precision. Methods: Forty hemodynamically stable hemodialysis patients underwent serial measurements of Nexfix arterial pressure (NAP) and BAP, respectively, through Nexfin and oscillometric devices. All BP measurements were recorded before starting hemodialysis. Results: The mean age of the patients was 68.9 ± 14.9 years with 65% older than 65 years and 30% older than 75; eleven subjects (27%) were diabetic. Vascular calcification, evaluated from the aortic arch to the iliac bifurcation, was detected in 87.5% of patients. Bland-Altman analysis comparing NAP measurements with BAP revealed the following outcomes: a mean bias ± limits of agreements (LA) of 15.3 ± 34.8 mm Hg (29% error) for systolic BP, a mean bias ± LA of -0.9 ± 20.34 mm Hg (32% error) for diastolic BP and a mean bias ± LA of 4.5 ± 21.34 mm Hg (26% error) for mean arterial pressure (MAP). Nexfin had poor precision in the reconstruction of diastolic and mean BP and was extremely inaccurate when evaluating systolic BP. Diabetes mellitus, peripheral neuropathy, and increase in systolic BAP significantly predicted the disagreement in systolic pressure measurement between NAP and MAP, F (3.34) = 10.787, p < 0.005, R² = 0.488. Conclusion: The Nexfin does not meet the criteria of interchangeability with oscillometric method in our hemodialysis patients. The negative influence of diabetes, neuropathy, and increase of systolic BAP on the reconstruction of systemic systolic pressure raises concerns about the feasibility of Nexfin in patients with a high prevalence of vasculopathy.

Continuous noninvasive monitoring of arterial pressure using the vascular unloading technique in comparison to the invasive gold standard in elderly comorbid patients: A prospective observational study

“…The authors suggested that the reason for the poor results of the Nexfin system might be related to the high prevalence of vasculopathy in their patient cohort with a mean age of 68.9 years. 13 In accordance to our study, best results were shown for MAP and SAP while performance for DAP again was worst. The diastole marks the lowest part of the arterial curve between two heartbeats.…”

“…Previous studies also described a rather poor performance of the Nexfin device and pulse contour analysis techniques during hypotension. 18,19,38 In a prospective study by Alfano et al, 13 the vascular unloading technique did not correspond to oscillometric blood pressure recordings in 40 hemodynamically stable patients requiring hemodialysis. The authors suggested that the reason for the poor results of the Nexfin system might be related to the high prevalence of vasculopathy in their patient cohort with a mean age of 68.9 years.…”

“…12 This noninvasive technique using different devices has already been investigated for its valid application for blood pressure monitoring in different clinical settings and patient categories, compared to either invasive or noninvasive blood pressure measurement. [13][14][15][16][17] Poor performance of noninvasive finger blood pressure monitoring was mostly related to critically ill patients and clinical situations with reduced perfusion due to severe hypotension, disease-related peripheral oedema, use of vasopressors or hypothermia. 18,19 Furthermore, an early study described age-dependent differences in the clinical reliabilty of arterial pressure measurements due to a degenerative decline in peripheral reflection coefficient resulting from decreased distensibility of peripheral arteries.…”

Improving Perioperative Outcomes Through Minimally Invasive and Non-invasive Hemodynamic Monitoring Techniques

“…According to the Association for the Advancement of Medical Instrumentation (AAMI), product standard uses the mean difference in BP measurements between these devices and “gold standard” measurements should be <5 mmHg, with a standard deviation <8 mmHg ( 3 ). Alfano et al compared finger-cuff with a conventional oscillometric method in 40 hemodynamically stable hemodialysis patients ( 14 ) and found that the measured values were significantly different between the two methods. This study included an elderly population (65% of whom were over 65 years of age), where vascular calcifications are recognized in up to 88% of the patients.…”

Measurement of Vital Signs Using Lifelight Remote Photoplethysmography: Results of the VISION-D and VISION-V Observational Studies

“…The software captures the average color of multiple regions of interest 30 times every second for 60 seconds; subtle changes in coloration are used to determine VSs (Figure 1). [15][16][17] Weighted average of performance of 3 devices 2.2 (9.2) Pulse rate (beats per minute) [15,16,18,19] Weighted average of performance of 4 devices 2.3 (5.0) Respiratory rate (respirations per minute) Finger photoplethysmography monitor [20][21][22][23][24][25] Weighted average of performance of 6 devices 6.7 (15.3) Systolic blood pressure (mmHg) [20][21][22][23][24][25] Weighted average of performance of 6 devices 5.5 (8.9) Diastolic blood pressure (mmHg) a Relevance and quality scores: 3.0-3.16 for pulse rate, 2.83-3.16 for respiratory rate, 2.83-3.5 for systolic/diastolic blood pressure. Here, we report early validation steps of the Lifelight software for the measurement of PR, RR, SBP, and diastolic BP (DBP; in line with the intended purpose of Lifelight) [26].…”