Monitoring of Cardiac Output Using a New Smartphone Application (Capstesia) vs. Vigileo FloTrac System

Abstract

(1) Background: We tested Capstesia against a reference system, Vigileo FloTrac, in patients undergoing major vascular surgery procedures. (2) Methods: Twenty-two adult patients (236 data pairs) were enrolled. Cardiac output (CO), stroke volume (SV), systemic vascular resistance (SVR), and related indexed parameters from the two monitoring systems were collected and compared at eleven time points during surgery. Intraclass correlation coefficients with 95% confidence intervals (CIs) and Bland–Altman plots with percentages of error were used. (3) Results: The interclass correlation coefficients for CO, SV, and SVR were 0.527 (95%CI 0.387 to 0.634), 0.580 (95%CI 0.454 to 0.676), and 0.609 (95%CI 0.495 to 0.698), respectively. In the Bland–Altman analysis, bias (and limits of agreement) of CO was 0.33 L min⁻¹ (−2.44; 3.10), resulting in a percentage error of 61.91% for CO. For SV, it was 5.02 mL (−36.42; 46.45), with 57.19% of error. Finally, the bias (and limit of agreement) of SVR was −75.99 dyne sec cm⁻⁵ (−870.04; 718.06), resulting in an error of 69.94%. (4) Conclusions: Although promising, cost-effective, and easy to use, the moderate level of agreement with Vigileo and the high level of error make Capstesia unsuitable for use in the intraoperative setting of vascular surgery. Critical errors in acquisition or digitalization of the snap might have a strong impact on the accuracy and performance. Further standardization of the acquisition technique and improvements in the processing algorithm are needed.