Abstract 279: Real-time Cerebral Hemoglobin Concentration Changes From NIRS; a Valid Evaluation Method for Quality CPR Chest Compression in Out-of-Hospital Cardiac Arrest

Abstract

Background: Near-Infrared Spectroscopy (NIRS) is a non-invasive real-time measurement device capable of monitoring the cerebral perfusion volume and may potentially represent the efficacy of chest compression. Introduction: NIRS assesses cerebral hemoglobin concentration changes ([[Unable to Display Character: ⊿]]cHb) independently of pulse by utilizing adhesive sensors that are placed on the forehead where [[Unable to Display Character: ⊿]]cHb measurements are evaluated within the segment of cerebral tissue analyzed. [[Unable to Display Character: ⊿]]cHb waveforms are displayed real-time and reflect chest compression quality which we defined as compressions of adequate depth capable to increase cerebral perfusion manifesting as waveforms on monitor. We set out to identify whether a relationship between [[Unable to Display Character: ⊿]]cHb and quality chest compressions could be determined with NIRS. Method: We prospectively enrolled eight out-of-hospital cardiac arrest (OHCA) patients admitted to our ED. The exclusion criteria included trauma and age < 15. Seven (87.5%) underwent both [[Unable to Display Character: ⊿]]cHb evaluation with the NIRO200NX (Hamamatsu Photonics) using NIRS and compression depth evaluation with the MRx-QCPR (Philips Healthcare). Each 2-minute CPR session is administered by one same operator and may be relegated in-between CPR sessions. From the whole resuscitation process, we randomly selected from 3 CPR sessions over 100 [[Unable to Display Character: ⊿]]cHb waveforms for every subject (~30 waveforms per session) and investigated correlations between the selected [[Unable to Display Character: ⊿]]cHb waveforms amplitudes and the depth of their respective chest compression. Results: 2 (29%) were strongly correlated. Within each single 2-minute CPR session, significant correlation was observed, whereas the totality of three CPR sessions demonstrated poor correlations attributable to several CPR manipulators. Conclusion: Strong correlation appears to exist between [[Unable to Display Character: ⊿]]cHb waveforms and chest compression depth. NIRS can evaluate in real-time[[Unable to Display Character: ⊿]]cHb waveform and may potentially serve as an index to evaluate quality CPR chest compression.