Comparison of a Novel Non-Invasive Photoplethysmography Device, Capable of Continuous-Monitoring of Advanced Hemodynamic and Cardiac Parameters, to the Existing Invasive Gold Standard Device, in a Porcine Model of Shock

Introduction: Organ failure is a common complication of shock. Balanced fluid resuscitation can improve tissue damage and prevent multiple system failure. Existing means of measuring hemodynamic status are invasive, expensive, complex to use and associated with complications. In this study, the reliability of an innovative noninvasive photoplethysmography device (PPG) for hemodynamic monitoring was compared it to the invasive gold standard.

Methods: Hemorrhagic shock was induced in ten swine. Animals were continuously monitored by the PPG device and a Swan Ganz Catheter. Readings of Systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), cardiac output(CO) and oxygen saturation(SO2) were compared.

Results: 290 data points were collected for each of the parameters at different baseline and different stages of hemodynamic shock. A significant correlation was found between the two monitoring devices (a slope not different from 1, P<0.05) for all four parameters. In all parameters, the average difference between the devices readings were insignificant (P<0.05), with the exception of CO for which a borderline difference was found. In addition, the total of all measurements which diverged from the standard deviation for all parameters was between 4.1% and 5.8%.

Discussion: There is a clear need for a technology capable of monitoring advanced hemodynamic signs. In this study, we have found that the novel PPG device offers a high level of reliability comparable to the existing invasive standard device. Pursuant to further trials, a device like this can offer a simple and reliable monitoring in a variety of clinical settings even in prehospital care.