Continuous Non-invasive finger cuff CareTaker® comparable to invasive intra-arterial pressure in patients undergoing major intra-abdominal surgery

Abstract

BackgroundDespite increased interest in non-invasive arterial pressure monitoring, the majority of commercially available technologies have failed to satisfy the limits established for the validation of automatic arterial pressure monitoring by the Association for the Advancement of Medical Instrumentation (AAMI). According to the ANSI/AAMI/ISO 81060–2:2013 standards, the group-average accuracy and precision are defined as acceptable if bias is not greater than 5 mmHg and standard deviation is not greater than 8 mmHg. In this study, these standards are used to evaluate the CareTaker® (CT) device, a device measuring continuous non-invasive blood pressure via a pulse contour algorithm called Pulse Decomposition Analysis.MethodsA convenience sample of 24 patients scheduled for major abdominal surgery were consented to participate in this IRB approved pilot study. Each patient was monitored with a radial arterial catheter and CT using a finger cuff applied to the contralateral thumb. Hemodynamic variables were measured and analyzed from both devices for the first thirty minutes of the surgical procedure including the induction of anesthesia. The mean arterial pressure (MAP), systolic and diastolic blood pressures continuously collected from the arterial catheter and CT were compared. Pearson correlation coefficients were calculated between arterial catheter and CT blood pressure measurements, a Bland-Altman analysis, and polar and 4Q plots were created.ResultsThe correlation of systolic, diastolic, and mean arterial pressures were 0.92, 0.86, 0.91, respectively (p < 0.0001 for all the comparisons). The Bland-Altman comparison yielded a bias (as measured by overall mean difference) of −0.57, −2.52, 1.01 mmHg for systolic, diastolic, and mean arterial pressures, respectively with a standard deviation of 7.34, 6.47, 5.33 mmHg for systolic, diastolic, and mean arterial pressures, respectively (p < 0.001 for all comparisons). The polar plot indicates little bias between the two methods (90%/95% CI at 31.5°/52°, respectively, overall bias = 1.5°) with only a small percentage of points outside these lines. The 4Q plot indicates good concordance and no bias between the methods.ConclusionsIn this study, blood pressure measured using the non-invasive CT device was shown to correlate well with the arterial catheter measurements. Larger studies are needed to confirm these results in more varied settings. Most patients exhibited very good agreement between methods. Results were well within the limits established for the validation of automatic arterial pressure monitoring by the AAMI.

Wireless vitals—Proof of concept for wireless patient monitoring in an emergency department setting

“…Also, data may be easily fed directly into most electronic health record systems and potentially integrated with tools for clinical decision support. Several wireless monitoring systems have been presented , but they still make some use of tubes or wires to connect the unit to the patient. As an alternative, solutions using acoustic detectors, infrared cameras or radar have been suggested.…”

Review of emerging methods and techniques for arterial pressure and flow waves acquisition and analyses

“…Accuracy of the noninvasive finger cuff CareTaker® has been studied according to the AAMI recommendations. 70 The correlations of SAP, DAP, and MAP were 0.92, 0.86, 0.91, respectively. The Bland-Altman comparison showed a bias of -0.57 (SD 7.34), -2.52 (SD 6.47), 1.01 (SD 5.33) mmHg accordingly.…”

Cuffless Blood Pressure Monitors: Principles, Standards and Approval for Medical Use

“…The time difference between the arrival of P1 and the second reflection pulse (P3) is referred to as T1-3, and corresponds to changes in arterial PP. The BP was estimated from the pulse peaks and parameters included in the PDA model [9][10][11][12][13].…”