Neumann Tobias, Finke Simon-Richard, Henninger Maja, Lemke Sebastian, Hoepfner Ben, Steven Daniel, Maul Alexandra C, Schroeder Daniel C, Annecke Thorsten
University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Anaesthesiology and Intensive Care Medicine, Research Group "Clinical Research and Teaching", Kerpener Str. 62, 50937 Cologne, Germany.
University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Electrophysiology, Kerpener Str. 62, 50937 Cologne, Germany.
Resusc Plus. 2020 Jun 1;1-2:100006. doi: 10.1016/j.resplu.2020.100006. eCollection 2020 Mar-Jun.
Prognosis in out-of-hospital cardiac arrest (OHCA) depends on cardiopulmonary resuscitation (CPR) duration. Therefore, the optimal biphasic defibrillation waveform shows high conversion rates besides low energy. Matthew Fishler theoretically predicted it to be truncated ascending exponential. We realised a prototypic defibrillator and compared ascending with conventional rectangular waveforms in modelled OHCA and CPR.
Approved by the authorities, 57 healthy swine (Landrace × Piétrain) were randomised to ASCDefib ( 26) or CONVDefib ( 26). Five swine served as sham control. We induced ventricular fibrillation (VF) electrically in anaesthetised swine randomised to ASCDefib or CONVDefib and discontinued mechanical ventilation. After 5 min of untreated cardiac arrest, we started CPR with mechanical chest compressions and ventilation. We performed transthoracic biphasic defibrillations after 2, 4, 6 and 8 min CPR targeting 4 J/kg in either group. Depending on the randomised group, the defibrillation protocol was either three ascending followed by one rectangular waveform (ASCDefib) or three rectangular followed by one ascending waveform (CONVDefib).
Under our model-specific conditions, VF was initially terminated by 13/80 ascending waveforms and 13/79 rectangular waveforms and persistent return of spontaneous circulation was achieved in 8/26 (ASCDefib) vs. 10/26 (CONVDefib) animals. Mean current rather than waveform design was predictive for defibrillation success in a generalised linear model.
Contrary to theoretical assumptions, transthoracic biphasic defibrillation with ascending waveforms is not superior to rectangular waveforms in modelled OHCA. We advocate defibrillation dosage to be guided by current, that has proven its predictive value again.
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院外心脏骤停（OHCA）的预后取决于心肺复苏（CPR）持续时间。因此，除了能量较低外，最佳双相除颤波形还应具有高转化率。马修·菲什勒从理论上预测其为截断上升指数波形。我们制作了一台原型除颤器，并在模拟的OHCA和CPR中比较了上升波形与传统矩形波形。
经当局批准，将57头健康猪（长白猪×皮特兰猪）随机分为ASCDefib组（26头）或CONVDefib组（26头）。5头猪作为假手术对照。我们对随机分为ASCDefib组或CONVDefib组的麻醉猪进行电诱导室颤（VF），并停止机械通气。在未经治疗的心脏骤停5分钟后，我们开始进行机械胸外按压和通气的CPR。在CPR 2、4、6和8分钟后，两组均进行经胸双相除颤，目标能量为4 J/kg。根据随机分组情况，除颤方案要么是三个上升波形后接一个矩形波形（ASCDefib），要么是三个矩形波形后接一个上升波形（CONVDefib）。
在我们特定模型的条件下，最初13/80个上升波形和13/79个矩形波形终止了VF，8/26只动物（ASCDefib组）与10/26只动物（CONVDefib组）实现了自主循环持续恢复。在广义线性模型中，平均电流而非波形设计可预测除颤成功。
与理论假设相反，在模拟的OHCA中，采用上升波形的经胸双相除颤并不优于矩形波形。我们主张除颤剂量应以电流为指导，电流再次证明了其预测价值。
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