Novel CPR system that predicts return of spontaneous circulation from amplitude spectral area before electric shock in ventricular fibrillation

作者：Nakagawa Yoshihide^*; Amino Mari; Inokuchi Sadaki; Hayashi Satoshi; Wakabayashi Tsutomu; Noda Tatsuya

来源：Resuscitation, 2017, 113: 8-12.

DOI：10.1016/j.resuscitation.2016.12.025

• Ventricular fibrillation
• Defibrillation
• Out-of-hospital cardiac arrest
• Waveform analysis
• Amplitude spectral area

Aim: Amplitude spectral area (AMSA), an index for analysing ventricular fibrillation (VF) waveforms, is thought to predict the return of spontaneous circulation (ROSC) after electric shocks, but its validity is unconfirmed. We developed an equation to predict ROSC, where the change in AMSA (Delta AMSA) is added to AMSA measured immediately before the first shock (AMSA1). We examine the validity of this equation by comparing it with the conventional AMSA1-only equation.
Method: We retrospectively investigated 285 VF patients given prehospital electric shocks by emergency medical services. Delta AMSA was calculated by subtracting AMSA1 from last AMSA immediately before the last prehospital electric shock. Multivariate logistic regression analysis was performed using post-shock ROSC as a dependent variable.
Results: Analysis data were subjected to receiver operating characteristic curve analysis, goodness-of fit testing using a likelihood ratio test, and the bootstrap method. AMSA1 (odds ratio (OR) 1.151, 95% confidence interval (CI) 1.086-1.220) and Delta AMSA (OR 1.289, 95% CI 1.156-1.438) were independent factors influencing ROSC induction by electric shock. Area under the curve (AUC) for predicting ROSC was 0.851 for AMSA1-only and 0.891 for AMSA1 + Delta AMSA. Compared with the AMSA1-only equation, the AMSA1 + Delta AMSA equation had significantly better goodness-of-fit (likelihood ratio test P < 0.001) and showed good fit in the bootstrap method.
Conclusions: Post-shock ROSC was accurately predicted by adding Delta AMSA to AMSA1. AMSA-based ROSC prediction enables application of electric shock to only those patients with high probability of ROSC, instead of interrupting chest compressions and delivering unnecessary shocks to patients with low probability of ROSC.

• 出版日期2017-4