Abstract 2688: Automated Rhythm Analysis To Reduce Pauses During Cardiopulmonary Resuscitation
Background: Pauses in cardiopulmonary resuscitation (CPR) for Automatic External Defibrillator (AED) ECG analysis may adversely affect cardiac arrest resuscitation. Thus, approaches that analyze the ECG rhythm during CPR may improve outcomes. We developed and tested an Analysis During CPR (ADC) algorithm to determine if it would meet the American Heart Association recommended 90% sensitivity for coarse (>0.2 mV peak-peak) ventricular fibrillation (VF) and 95% specificity for non-shockable rhythms.
Methods: Defibrillator ECG and impedance recordings from 162 patients were retrospectively gathered from 3 EMS systems. 1047 15-second CPR-artifacted segments (274 coarse VF + 773 non-shockable) were identified for analysis; their artifact and rhythm distributions reflect those found in the 162 patients. Each CPR artifacted segment was paired with an adjacent segment free of CPR artifact for reference. Independent reviewers manually annotated and verified Shock/No-Shock rhythm designations blinded to the ADC determination. The ADC algorithm automatically classified each segment into categories of Shock/No Shock/Pause CPR For Clean Analysis, where the last category is segments recognized by the ADC as too noisy for accurate Shock/No Shock determination. In those situations the device would revert to the current approach of a CPR pause for AED rhythm analysis.
Results: Of the 1047 CPR-artifacted segments, the ADC recommended to “Pause CPR For Clean Analysis” in 10% (n=109), including 4.4% of VF segments (12/274) and 12% (97/773) of non-shockable segments. Of the 938 remaining segments, the ADC correctly identified VF in 97% (sensitivity: 255/262) and correctly identified nonshockable rhythms in 96% (specificity: 650/676). Corresponding positive and negative predictive values were 91% and 99% respectively.
Conclusions: The ADC is the first algorithm for automated ECG rhythm analysis during ongoing CPR that has been demonstrated to meet the existing AHA sensitivity and specificity recommendations designed for traditional rhythm analysis during hands-off pauses. Incorporation of this algorithm into an AED may eliminate about 90% of analysis pauses without compromising analysis accuracy and in turn may improve the likelihood of resuscitation.