Abstract 151: Software Annotation of Defibrillator Files: Ready for Prime Time?

Abstract

Introduction: Defibrillators record important information about the quality of chest compressions during CPR. Software made for reviewing defibrillator files automatically annotate and measure chest compression metrics. However, evidence is limited regarding the accuracy of such measurements. Objective: To compare chest compression fraction (CCF) and rate measurements made with software annotation vs. manual annotation of defibrillator files. Methods: This is a retrospective, observational study from the Dallas Fort-Worth site of the Resuscitation Outcomes Consortium. We reviewed chest compression waveforms from the bioimpedance channel of defibrillator recordings (Physio-Control Lifepak 12 and 15, Redmond, WA) of 100 prehospital patients enrolled in the DFW Cardiac Arrest Registry from 9/8/2018 to 3/9/2019. Included cases were ≥18 years, had presumed cardiac cause of arrest, and continuous chest compressions. We assessed chest compression waveforms from the time of initial CPR until the time the defibrillator was removed. A trained reviewer revised the software annotations by marking the start and end of CPR and adding or removing chest compressions. Software annotated and manual reviewer annotated measurements were compared for CCF and rate using intraclass correlation coefficient (ICC) statistical analysis. Results: Mean patient age was 63 years with 59% male. The mean (±SD) duration of CPR was 30.4 ± 10.6 min. The overall mean CCF for files annotated by software vs. manual annotation was 0.64 ± 0.19 vs. 0.86 ± 0.07, respectively, and the ICC was 0.14. For software vs. manual annotation, the overall mean rate was 109 ± 10 vs. 108 ± 10, respectively, and ICC was 0.99. The software misidentified epochs before the start of chest compressions, failed to capture epochs after resuscitation ended, and after return of spontaneous circulation, resulting in low ICC for CCF. The ICC was excellent for compression rate because the software only counted epochs where chest compressions were actually given. Conclusions: Software annotation performed poorly for chest compression fraction and very well for chest compression rate. Defibrillator files must be reviewed and annotated manually before quality of chest compression measurements are calculated.