Abstract 19355: Sequential Shock-No Shock Algorithm to Reduce Interruption During Cardiopulmonary Resuscitation
Introduction: Pauses in CPR especially those around shocks have been associated with lower likelihood of survival in cardiac arrest. Chest compressions (CC) can induce artifacts that obscure ECG signals and challenge rhythm analysis. Currently all defibrillators require a pause in CC to determine if defibrillation is needed. This study evaluated the potential of a shock-no shock algorithm that would operate during CC as a strategy to reduce CC interruption.
Methods: We evaluated a 2-step sequential algorithm. The algorithm continuously analyzes rhythms during CC to identify underlying shockable rhythm. If the algorithm does not identify a shockable rhythm after a time period, CCs are interrupted for further rhythm analysis. This approach was tested with data from 236 out-of-hospital cardiac arrest patients recorded by Philips MRx defibrillators using a 1 minute time period as a point to report algorithm accuracy. ECG segments were reviewed manually by rhythm experts. The rhythm was classified as shockable when the rhythms immediately before and after the CC period were shockable and without intervening shock (n=96), and as non-shockable when the rhythms before and after the CC period were non-shockable (n=461). We evaluated the time-dependent sensitivity/specificity (SE/SP) of the algorithm.
Results: The SE/SP for identifying shockable rhythm was 81.3%/99.4% after the first 11 seconds of analysis during CC (Figure). With ongoing analysis through 1 minute of CC, the SE/SP was 91.7%/98.5%. After CC-free analysis, the algorithm achieved a SE/SP of 100%/97.6%.
Conclusions: An algorithm that reads through CC provides a strategy to forgo CC interruption to identify shockable rhythms in over 90% while still achieving a high level of accuracy for the shock-no shock decision consistent with algorithms that require CC interruption for every rhythm analysis. Such an approach has the potential to substantially reduce CC interruptions to identify shockable rhythms.
Author Disclosures: C. Liu: Employment; Significant; Philips. S. Gehman: Employment; Significant; Philips. D. Jorgenson: Employment; Significant; Philips. T. Lyster: Employment; Significant; philips. J. Coult: None. M.S. Eisenberg: None. P.J. Kudenchuk: None. T.D. Rea: Research Grant; Modest; Medtronic Foundation, Medic One Foundation, Life Sciences Discovery Fund. L.D. Sherman: None.
- © 2016 by American Heart Association, Inc.