Kerber R E, McPherson D, Charbonnier F, Kieso R, Hite P
Circulation. 1985 Jan;71(1):136-40. doi: 10.1161/01.cir.71.1.136.
In defibrillation, current flow depends on the energy selected and the transthoracic impedance. If transthoracic impedance is high, current flow may be inadequate to defibrillate. We developed a method by which high transthoracic impedance is automatically compensated for by an increase in operator-selected energy when impedance is high. Transthoracic impedance was predicted in advance of the first shock by passing a low-level current between the defibrillator electrodes during the defibrillator charge cycle; a microprocessor monitored current flow and determined impedance. In 28 mongrel dogs we manipulated transthoracic impedance by placing glycerin-soaked gauze pads between the paddle electrodes and the chest. If the predicted impedance exceeded a preset value, the delivered energy was automatically increased by 40% or 100%. Using this impedance-based energy adjustment technique, we found significant improvements in current flow and success rate of shocks when energy was automatically increased to compensate for high transthoracic impedance. The use of transthoracic impedance as a basis for energy adjustment appears a promising technique to minimize the hazards of high electrical energy; it allows low-energy shocks in most patients while avoiding inappropriate low energies in patients with high impedance. Clinical trials are justified.
在除颤过程中，电流的流动取决于所选能量和经胸阻抗。如果经胸阻抗较高，电流流动可能不足以实现除颤。我们开发了一种方法，当阻抗较高时，通过增加操作者选择的能量来自动补偿高经胸阻抗。在除颤器充电周期期间，通过在除颤器电极之间施加低水平电流来预先预测首次电击前的经胸阻抗；微处理器监测电流流动并确定阻抗。在28只杂种狗中，我们通过在电极板与胸部之间放置甘油浸泡的纱布垫来控制经胸阻抗。如果预测阻抗超过预设值，输送的能量会自动增加40%或100%。使用这种基于阻抗的能量调整技术，我们发现当能量自动增加以补偿高经胸阻抗时，电流流动和电击成功率有显著提高。将经胸阻抗用作能量调整的基础似乎是一种很有前景的技术，可将高电能的危害降至最低；它能使大多数患者接受低能量电击，同时避免高阻抗患者接受不适当的低能量电击。临床试验是合理的。
