The Weil Institute of Critical Care Medicine, Rancho Mirage, CA 92270, USA.
Resuscitation. 2009 Nov;80(11):1312-7. doi: 10.1016/j.resuscitation.2009.08.004. Epub 2009 Aug 31.
Impedance compensation methods differ markedly among manufacturers and can play an important role in defibrillation success. In this study we compared the efficacy of two different commercial defibrillators based on defibrillation success in a high impedance porcine model of cardiac arrest. The first defibrillator (A) compensates high impedance by controlling current with fixed shock duration, while the second defibrillator (B) by prolonging the shock duration.
In 10 domestic male pigs weighing between 17 and 28 kg, ventricular fibrillation was electrically induced and untreated for 15s. Animals were randomized to receive defibrillations with either defibrillator A or defibrillator B, at maximum energy settings of which were 200 J for the defibrillator A and 360 J for the defibrillator B. A grouped up-down defibrillation threshold testing protocol was used to compare the success rate between the two defibrillators. A variable resistance, ranging from 80 to 200 ohm was placed in series with the defibrillation pads. After a recovery interval of 5 min, the sequence was repeated for a total of 60 test shocks for each animal.
The measured total pathway impedance was in a range of 108-278 ohm. The combined success rate was 49.5% for the two defibrillators in a total of 600 testing shocks. The success rate was significantly higher when the defibrillator A was employed in comparison with defibrillator B (63% vs. 36%, p=0.0001).
For transthoracic impedances greater than average, the current-based compensation technique was more effective than the duration-based compensation technique.
制造商之间的阻抗补偿方法差异显著，在除颤成功中起着重要作用。本研究比较了两种不同商业除颤器在高阻抗猪心搏骤停模型中的除颤效果。第一种除颤器（A）通过控制固定电击持续时间的电流来补偿高阻抗，而第二种除颤器（B）通过延长电击持续时间来补偿。
在 10 只体重 17 至 28 公斤的雄性国内猪中，通过电刺激诱导心室颤动，且未进行治疗 15 秒。动物随机接受两种除颤器的除颤治疗，其中除颤器 A 的最大能量设置为 200 J，除颤器 B 的最大能量设置为 360 J。采用分组上下除颤阈值测试方案比较两种除颤器的成功率。在除颤垫上串联一个可变电阻，范围为 80 至 200 欧姆。在 5 分钟的恢复间隔后，对每个动物重复进行总共 60 次测试电击。
测量的总通路阻抗在 108 至 278 欧姆范围内。两种除颤器在总共 600 次测试电击中，总成功率为 49.5%。与除颤器 B 相比，除颤器 A 的成功率显著更高（63%对 36%，p=0.0001）。
对于大于平均阻抗的经胸阻抗，基于电流的补偿技术比基于持续时间的补偿技术更有效。
