A series of case studies on detection of spontaneous pulse by photoplethysmography in cardiopulmonary resuscitation.

Objective: This work investigates the potential of photoplethysmography (PPG) to detect a spontaneous pulse from the linger, nose or ear in order to support pulse checks during cardiopulmonary resuscitation (CPR). Methods: In a prospective single-center cross-sectional study, PPG signals were acquired from cardiac arrest victims who underwent CPR. The PPG signals were analyzed and compared to arterial blood pressure (ABP) signals as a reference during three distranaisco; Date: 2/2/2020; Time:18:44:23inct phases of CPR: compression pauses, on-going compressions and at very low arterial blood pressure. Data analysis was based on a qualitative subjective visual description of similarities of the frequency content of PPG and ABP waveform. Results: In 9 patients PPG waveforms corresponded to ABP waveforms during normal blood pressures. During ABP in the clinically challenging range of 60 to 90 mmHg and during chest compressions and pauses. PPG continued to resemble ABP, as both signals showed similar frequency components as a result of chest compressions as well as cardiac activity. Altogether 1199 s of PPG data in compression pauses were expected to show a spontaneous pulse, of which 732 s (61%) of data were artifact-free and showed the spontaneous pulse as visible in the ABP. Conclusions: PPG signals at all investigated sites can indicate pulse presence at the moment the heart resumes beating as verified via the ABP signal. Therefore, PPG may provide decision support during CPR, especially related to preventing and shortening interruptions for unnecessary pulse checks. This could have impact on CPR outcome and should further be investigated. (C) 2019 The Authors. Published by Elsevier Inc.