Atkins D L, Kerber R E
Department of Pediatrics, University of Iowa, Iowa City 52242.
Pediatrics. 1994 Jul;94(1):90-3.
Current flow, the major determinant of defibrillation success, depends on delivered energy and transthoracic impedance. Previous experimental data suggest that transthoracic impedance is higher using "pediatric" electrode paddles compared to the larger "adult" electrode paddles. There are few data from actual shocks to support the experimental studies. The purpose of this study was to measure transthoracic impedance during actual shock delivery and to determine the optimal electrode paddle size for pediatric defibrillation and cardioversion.
We prospectively evaluated all shocks of < or = 20 joules given to pediatric patients at the University of Iowa from 1988 to 1992. Data collected included energy selected by the operator, energy delivered by the defibrillator, peak current flow and transthoracic impedance. Data were analyzed by unpaired t test and linear regression.
Fifty-five shocks were delivered to 20 patients, age newborn to 8 years. Thirty-seven shocks were given with "pediatric" electrode paddles (surface area 21 cm2) and 18 with "adult" electrode paddles (surface area 83 cm2). Selected energy correlated well with delivered energy (r = .98, P < .0001). Delivered energy using "pediatric" electrodes did not differ from that delivered with "adult" electrodes (8.0 +/- 0.9 joules vs 10.5 +/- 1.2 joules P > .1). However transthoracic impedance was significantly higher with "pediatric" electrodes (78.1 +/- 4.4 ohms vs 54.6 +/- 2.7 ohms P < .0008), resulting in lower peak current flow through "pediatric" electrode paddles (6.2 +/- 0.5 amps vs 8.7 +/- 0.5 amps P < .002). There was no correlation between joules/kg and peak current flow (r = .26, P > .05).
Use of "pediatric" electrode paddles results in higher transthoracic impedance and thus lower peak current flow. In pediatric defibrillation, larger "adult" electrode paddles should be used as soon as chest size permits (approximately 10 kg). Lower transthoracic impedance results in higher current flow that facilitates cardioversion and defibrillation.
电流是除颤成功的主要决定因素，它取决于输送的能量和经胸阻抗。先前的实验数据表明，与较大的“成人”电极板相比，使用“儿科”电极板时经胸阻抗更高。来自实际电击的数据很少能支持这些实验研究。本研究的目的是测量实际电击过程中的经胸阻抗，并确定儿科除颤和心脏复律的最佳电极板尺寸。
我们前瞻性评估了1988年至1992年在爱荷华大学对儿科患者给予的所有≤20焦耳的电击。收集的数据包括操作者选择的能量、除颤器输送的能量、峰值电流和经胸阻抗。数据采用不成对t检验和线性回归分析。
对20例年龄从新生儿到8岁的患者进行了55次电击。37次电击使用“儿科”电极板（表面积21平方厘米），18次使用“成人”电极板（表面积83平方厘米）。选择的能量与输送的能量相关性良好（r = 0.98，P < 0.0001）。使用“儿科”电极输送的能量与使用“成人”电极输送的能量没有差异（8.0±0.9焦耳对10.5±1.2焦耳，P > 0.1）。然而，“儿科”电极的经胸阻抗显著更高（78.1±4.4欧姆对54.6±2.7欧姆，P < 0.0008），导致通过“儿科”电极板的峰值电流更低（6.2±0.5安培对8.7±0.5安培，P < 0.002）。焦耳/千克与峰值电流之间没有相关性（r = 0.
