Optimizing the duration of CPR prior to defibrillation improves the outcome of CPR in a rat model of prolonged cardiac arrest

AimsThis study was to investigate whether optimal duration of CPR prior to defibrillation could be guided by Amplitude Spectrum Analysis (AMSA) in the setting of prolonged VF on outcome of CPR.MethodsVF was induced in thirty Sprague-Dawley rats and untreated for 8 minutes. Animals were then randomized into 3 groups prior to CPR: The duration of CPR prior to defibrillation was guided by AMSA (CC+AMSA); guidelines-based with delayed defibrillation that simulated the AED algorithm (GL+AED); and guidelines-based with immediate shock (GL+shock ready).ResultsRegardless of groups, the majority of the animals (85%) required over 5 min of CPR to achieve restoration of spontaneous circulation (ROSC). Significantly greater rate of ROSC after first defibrillation (70% vs 0%, p < 0.01), lesser CPR interruptions and the number of defibrillations were observed in the CC+AMSA group when compared to both guidelines-based groups (p < 0.001). This was associated with a significantly better post-resuscitation myocardial and neurological function and longer durations of survival.ConclusionsAfter prolonged VF, optimal duration of CPR prior to defibrillation guided by AMSA improves the outcome of CPR.