[Downloaded free from http://www.ijaweb.org on Monday, August 13, 2018, IP: 109.167.108.140] Original Article Cardiac output monitoring: A comparative prospective observational study of the conventional cardiac output monitor Vigileo™ and the new smartphone‑based application Capstesia™ Address for correspondence: Shagun Bhatia Shah, Ajay Kumar Bhargava, Uma Hariharan1, Dr. Shagun Bhatia Shah, Gayatri Vishvakarma2, Chamound Rai Jain, Anamica Kansal H. No. 174-175, Ground Floor, 2 Pocket-17, Sector-24, Rohini, Rajiv Gandhi Cancer Institute and Research Centre, Research Department, Rajiv Gandhi Cancer Institute and Research Centre, 1Department of Anaesthesia, Dr. Ram Manohar Lohia Hospital and PGIMER, CHS, New Delhi - 110 085, India. New Delhi, India E-mail: drshagun_2010@ rediffmail.com ABSTRACT Background and Aims: Capstesia is a software designed for smartphones (AndroidTM/iOSTM) to estimate the cardiac output and other haemodynamic variables from the waveform obtained from an invasive arterial cannula. The technology has been validated by studies in simulated environmental conditions. We compared the cardiac output (CO) and stroke volume variation (SVV) obtained by conventional cardiac output monitor VigileoTM with CO and pulse pressure variation (PPV) extracted from CapstesiaTM, under clinical conditions, intraoperatively. Methods: In a Samsung smartphone in which the Capstesia software had been downloaded, the application was opened and a snapshot of the arterial waveform from the monitor screen of anaesthesia workstation was taken. The application instantaneously calculates the CO and PPV after inputting the heart rate and the systolic and diastolic blood pressure variables. These values were then compared Access this article online with readings from the VigileoTM monitor. Data was collected from 53 patients and analysed. Website: www.ijaweb.org Results: Five hundred and thirty data pairs of CO and an equal number of SVV and PPV pairs were analysed. Cardiac index by Capstesia (CIcap) was found to have a positive correlation with DOI: 10.4103/ija.IJA_783_17 cardiac index by Vigileo (CIvig) using the intraclass correlation for raters, the strength of correlation Quick response code being 0.757. Upper and lower 95% confidence limits were 1.43 l/min/m2 and − 1.14 l/min/m2 (Bland Altman’s plot). A positive correlation was found between SVV and PPV using the Pearson’s correlation (r = 0.732). Conclusion: CapstesiaTM is a reliable and feasible alternative to VigileoTM for intraoperative CO monitoring in oncosurgical patients. Key words: Capstesia, cardiac output, smartphone application, stroke volume variation, Vigileo INTRODUCTION pulse pressure variation (PPV), rate of left ventricular pressure rise during systole (dP/dt max), and stroke Accessibility and cost are two major constraints volume resistance (SVR) from pulse contour analysis for sophisticated haemodynamic monitoring in the perioperative period, besides the time consumed in This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, setting up of the monitor and technical expertise which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under required. Smartphones have emerged as an inseparable the identical terms. part of our daily routine. Capstesia™ (GalenicApp, For reprints contact: [email protected] Vitoria, Spain) smartphone application for AndroidTM/ iOSTM systems is a potentially transformative device How to cite this article: Shah SB, Bhargava AK, Hariharan U, that can make advanced cardiac monitoring simpler, Vishvakarma G, Jain CR, Kansal A. Cardiac output monitoring: A comparative prospective observational study of the conventional more affordable, and universally accessible. It can cardiac output monitor Vigileo™ and the new smartphone-based calculate the cardiac output (CO), cardiac index (CI), application Capstesia™. Indian J Anaesth 2018;62:584-91. 584 © 2018 Indian Journal of Anaesthesia | Published by Wolters Kluwer - Medknow Page no. 22 [Downloaded free from http://www.ijaweb.org on Monday, August 13, 2018, IP: 109.167.108.140] Shah, et al.: Haemodynamic monitoring – Capstesia and Vigileo compared of a snapshot of the arterial pressure waveform.[1,2] METHODS CapstesiaTM has immense clinical potential in patient care and monitoring intraoperatively, extending This single blind prospective observational single into the intensive care units. The smartphone can arm study is registered with the Clinical Trial Registry now double as an innovative, real time, advanced of India (Reg No: CTRI/2017/03/008198). It was haemodynamic monitor. CapstesiaTM may prove conducted from April 2017 to September 2017 in the instrumental in making advanced haemodynamic Major Operation Theatre of a tertiary care oncology monitoring accessible to remote operating rooms and centre after obtaining approval from the Scientific critical care units in the developing and developed Committee and Institutional Review Board of the world. A single android smartphone with online centre. The study was conducted in accordance with facility can simultaneously monitor the CO in any the Helsinki Protocol after taking written informed consent from all the patients. A total of 53 adult patients number of patients at a cost of five Euros a month. of either sex, aged between 20 and 75 years, weighing The mobile feature extraction technology utilised by between 40 and 90 kg, with ASA physical status II and CapstesiaTM has been validated by studies in simulated III undergoing elective major oncosurgery requiring environmental conditions,[3] but ours is the first placement of an arterial line and CO monitoring were reported study in the intraoperative period. included in the study. Patients with a Negative Allen’s test in bilateral radial arteries and in whom a radial Pulse contour analysis devices are broadly classified arterial line could not be secured were excluded from into (i) Devices requiring an indicator dilution CO the study. Patients having a pacemaker or automated measurement for pulse contour calibration (LiDCO implantable cardioverter-defibrillator in situ, persistent System; LiDCO, Cambridge, UK; and PiCCO System; arrhythmias, a history of heart and/or lung transplant, and intra-aortic balloon pump or other mechanical Pulsion, Munich, Germany), (ii) Devices requiring cardiac support were also excluded from the study. patient demographic and physical characteristics All patients scheduled for major surgery requiring CO for the estimation of arterial compliance (Vigileo; monitoring were considered to be potentially eligible. Flo-trac; Edwards Lifesciences, Irvine, CA, USA).[3] We Out of these, the patients who met our age and weight now have devices that do not require calibration or inclusion criteria were eligible. preloaded data (CapstesiaTM; Android/iOS smartphone application and MostCare System; Vyetech Health, Capstesia™ (GalenicApp, Vitoria, Spain) smartphone Padua, Italy). application for AndroidTM/iOSTM systems, is a software downloaded into a smartphone. It calculates the CO Our aim was to study the correlation and agreement by pulse contour analysis of a snapshot of the arterial between CI values (calculated from CO) obtained pressure waveform clicked by the smartphone. The by two different pulse contour analysis cardiac systolic blood pressure, diastolic blood pressure, TM TM output monitors, Vigileo and Capstesia . We and heart rate values have to be inputted into the recorded the cardiac output-vigileo (COvig), smartphone, and an internet connection is required stroke volume variation-vigileo (SVVvig), to obtain the CO and other advanced haemodynamic cardiac output-capstesia (COcap), pulse pressure parameters within seconds on the smartphone screen. variation-capstesia (PPVcap), dP/dt max (capstesia), No external calibration is required. The pulse contour heart rate (HR), systolic, diastolic and mean arterial analysis model is based on the interrelationship pressure at various time points and derived the CI by between blood pressure, SV, arterial compliance, dividing the CO with the body surface area (BSA). and SVR.[4] SV can be deduced from the arterial pressure waveform if the arterial compliance and Our primary objective defined and established a SVR are known. Aortic compliance is age-related[4] priori at initiation of the study design was to study and nonlinear, being high at low distending pressures if agreement and interchangeability exist between but rapidly reducing at higher pressures, which is an the CI measured by VigileoTM and that measured inbuilt mechanism to prevent overstretching.[5,6] SV by CapstesiaTM and to ascertain the strength of any multiplied by the HR provides the CO. Commercially existing correlation. Our secondary objectives were to available pulse contour systems, although based on the study if a correlation exists, first, between SVVvig and same basic principle, use dissimilar pressure-volume PPVcap, and second, between COcap and dP/dtmax. conversion algorithms.[6-8] Indian Journal of Anaesthesia | Volume 62 | Issue 8 | August 2018 585 Page no. 23 [Downloaded free from http://www.ijaweb.org on Monday, August 13, 2018, IP: 109.167.108.140] Shah, et al.: Haemodynamic monitoring – Capstesia and Vigileo compared VigileoTM (Edwards Lifescience, USA) CO monitor is infusion and peripheral nerve stimulator-guided attached to a Flo Trac sensor (disposable