Abstract 274: Pulse Detection with Photoplethysmography (PPG) in Hemodynamic Instability
Pulse detection could guide therapy but noninvasive methods accurate in emergencies remain elusive. We investigated feasibility of noninvasive pulse detection in hemodynamic instability in an emergency department.
Hypothesis: Pulse detection in hemodynamic instability may be feasible using PPG.
Methods: An algorithm detected pulses in signals from commercial oximeters (NICO, Oxypleth - Philips) applied to a peripheral (fingertip) and two central (nasal septum, ear pinna) sites and pressure catheters in radial arteries (Intellivue - Philips). Heart rates from average interpulse intervals in 3 s periods, were updated each second. Data was classified by systolic pressure. Rates from each oximeter site were compared to the arterial rate.
Results: We recorded over 140 hours of PPG signals from 30 patients during CPR, post-resuscitation care, shock and syncope from October 2012 to May 2013. Technical difficulties excluded 3 patients from analysis.
Even weak pulses were evident in PPG waveforms (figure).
Pulse detection was accurate for all sensors at all sites and pressures (table). Central sites tended to be more accurate than the finger at low pressures.
Conclusions: A noninvasive pulse detector using PPG appears feasible and may be useful in initial patient assessment, during pauses in CPR and during chest compressions.
- © 2013 by American Heart Association, Inc.