Kerber R E, Martins J B, Kienzle M G, Constantin L, Olshansky B, Hopson R, Charbonnier F
Cardiovascular Division, University of Iowa, Iowa City.
Circulation. 1988 May;77(5):1038-46. doi: 10.1161/01.cir.77.5.1038.
The purposes of this study were two. First, we wanted to evaluate in patients a technique for automated adjustment of selected energy for defibrillation or cardioversion based on transthoracic impedance. Second, we wanted to define the relationship of peak current and shock success in various arrhythmias. Applying a previously validated method of predicting transthoracic impedance in advance of any shock, we modified defibrillators to automatically double the operator-selected energy if the predicted impedance exceeded 70 omega. Success rates of shocks given for ventricular and atrial arrhythmias from these modified energy-adjusting defibrillators were compared with success rates for shocks given from standard defibrillators. We prospectively collected data on 347 patients who received a total of 1009 shocks. Low-energy (100 J) shocks given to high-impedance (greater than or equal to 70 omega) patients had a poor success rate; in such high-impedance patients significant improvement in shock success rate was achieved by the energy-adjusting defibrillators. For example, when 100 J shocks were selected for high-impedance patients in ventricular fibrillation the energy-adjusting defibrillators achieved a shock success rate of 75%, whereas standard defibrillators achieved a shock success rate of only 36% (p less than .01). Similar improvements were seen for ventricular tachycardia and atrial fibrillation. Thus, automated energy adjustment based on transthoracic impedance is a beneficial approach to defibrillation and cardioversion. For ventricular fibrillation, atrial fibrillation, and atrial flutter there was a clear relationship between peak current and shock success.(ABSTRACT TRUNCATED AT 250 WORDS)
本研究有两个目的。其一，我们想在患者中评估一种基于经胸阻抗自动调整除颤或心脏复律所选能量的技术。其二，我们想明确各种心律失常中峰值电流与电击成功之间的关系。我们应用一种先前经验证可在任何电击前预测经胸阻抗的方法，对除颤器进行了改良，使其在预测阻抗超过70欧姆时自动将操作者所选能量加倍。将这些改良后的能量调整除颤器用于室性和房性心律失常的电击成功率与标准除颤器的电击成功率进行比较。我们前瞻性收集了347例患者的数据，这些患者共接受了1009次电击。对高阻抗（大于或等于70欧姆）患者给予低能量（100焦耳）电击的成功率较低；在这类高阻抗患者中，能量调整除颤器使电击成功率有了显著提高。例如，在心室颤动时为高阻抗患者选择100焦耳电击，能量调整除颤器的电击成功率为75%，而标准除颤器的电击成功率仅为36%（P<0.01）。室性心动过速和心房颤动也有类似改善。因此，基于经胸阻抗的自动能量调整是除颤和心脏复律的有益方法。对于心室颤动、心房颤动和心房扑动，峰值电流与电击成功之间存在明确关系。（摘要截选至250字）
