Abstract 137: A Photoplethysmography Signal Can Show the Presence of a Spontaneous Pulse at Sub--Life-Supporting Blood Pressure During Experimental Cardiopulmonary Resuscitation
Introduction: Detecting return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR) is challenging, time-consuming and interrupts chest compressions. Previously, in pigs undergoing 30:2 automated-CPR, we have shown that a spontaneous pulse can be recognized in a photoplethysmography (PPG) signal during compressions, supporting ROSC detection. When a spontaneous pulse appeared in the PPG signal during compressions, complexity of the signal increased, as frequency components associated with the spontaneous pulse appeared in addition to compression frequency components (Fig. 1). Here we determine at what arterial blood pressure (ABP) a spontaneous pulse appears.
Methods: We analyzed data from 9 pigs. The ABP was measured in the aortic arch. We calculated the mean arterial pressure (MAP) over 2.4 s (4 compression periods). We determined the MAP when a spontaneous pulse appeared in the PPG signal for the first time, the average MAP in the interval with increased complexity of the PPG signal, and the minimum pulse pressure (PP) in the first ventilation pause showing a spontaneous pulse in the PPG signal (Fig. 1).
Results: Figure 1 shows an example of PPG, ABP and MAP signals during CPR. In the 9 animals, when a spontaneous pulse appeared in the PPG signal for the first time, the MAP varied from 23 to 43 mmHg (mean 33 mmHg), and the minimum PP in the ventilation pause varied from 11 to 40 mmHg (mean 20 mmHg). In the interval with increased complexity of the PPG signal, the average MAP in the 9 animals varied from 48 to 129 mmHg (mean 77 mmHg).
Conclusion: A PPG signal can show myocardial viability through an underlying spontaneous pulse, which increases the complexity of the signal. This occurs over a wide range of MAPs and PPs, including those considered sub-life-supporting. Figure 1: At about 32:22, a spontaneous pulse appears in the PPG (0.3 Hz high-pass filtered) and ABP signals. CPR is delivered throughout the episode, with a 30:2 compression-ventilation ratio.
Author Disclosures: R. Wijshoff: Research Grant; Significant; This work was supported by NL Agency, IOP Photonic Devices, IPD083359 HIP – Hemodynamics by Interferometric Photonics. W. Peeters: None. A. Venema: None. R.M. Aarts: None. G. Noordergraaf: Consultant/Advisory Board; Significant; Gerrit Jan Noordergraaf is a consultant for Philips Research.
- © 2014 by American Heart Association, Inc.