Cardiac output monitoring: A comparative prospective observational study of the conventional cardiac output monitor Vigileo™ and the new smartphone-based application Capstesia

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 with readings from the VigileoTM monitor. Data was collected from 53 patients and analysed. 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 cardiac index by Vigileo (CIvig) using the intraclass correlation for raters, the strength of correlation 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.