自动体外除颤器与人工除颤器对幼猪室颤模型的除颤效果☆

背景：目前对8岁以下儿童电除颤的有效剂量及安全范围尚无统一的规定。 目的：使用自动体外除颤器及人工除颤器与儿童用电极对幼猪室颤模型除颤，进行有效性及安全性评价。 设计、时间及地点：实验猪电除颤体外实验，于2006-10/2007-05在苏州大学实验动物中心动物手术室完成。 材料：2月龄太湖猪30只，体质量7.0~25.0 kg，由常熟畜禽良种有限公司提供。 方法：30只幼年太湖猪，按体质量随机分为自动体外除颤器组和人工除颤组，每组15只。诱发室颤2 min后分别以自动体外除颤器及人工除颤器50 J除颤，一次电击后立即进行心肺复苏，不复律的动物以70 J电击后联用心肺复苏。除颤后不同时间做血气分析、电解质及心肌酶谱检查、超声波心功能测定和神经学打分，72 h后处死作大体解剖。 主要观察指标：动态监测整个实验过程动物心电图、血压、呼吸、体温等，检查除颤前后动物的超声心动图、血气、电解质、神经行为学打分以及大体解剖。 结果：两组动物50 J一次电击后立即给与心肺复苏，复苏成功率达86.7%；部分猪放电除颤后心电图ST段压低或抬高，并在几分钟内回到基线；两组动物除颤成功后心脏射血分数、左心室面积变化分数3.0~4.0 h内均显著降低(P < 0.05)，72 h恢复正常；血液分析各项指标与试验前差别无统计学意义(P > 0.05)；复苏后神经行为和大体解剖未见异常。 结论：应用成人双相波自动体外除颤器联用具备能量衰减配件的儿童专用电极，对7~25 kg的幼猪室颤模型取得了较满意的复苏效果。

Effect of automated external defibrillator and artificial defibrillator on piglet models of ventricular fibrillation

BACKGROUND: The optimal biphasic defibrillation dose for children, especially for those young than 8 years is unknown. OBJECTIVE: To evaluate the efficacy and safety of automated external defibrillator (AED) and artificial defibrillator, and biphasic waveform defibrillation on piglet models of ventricular fibrillation. DESIGN, TIME AND SETTING: The in vitro experiment regarding defibrillator on piglet models of ventricular fibrillation was performed at the Animal Operation Room, Laboratory Animal Center of Soochow University from October 2006 to May 2007. MATERIALS: Thirty Taihu piglets, aged 2-months old, weighing 7.0-25.0 Kg were provided by Changshu High-quality Animal Breeds Co., Ltd. METHODS: Thirty young Taihu pigs were divided into AED and artificial defibrillator groups according to the body weight, with 15 animals in each group. 50J energy was delivered respectively by AED and artificial defibrillator at 2 minutes after ventricular fibrillation, and immediately followed by cardiopulmonary resuscitation (CPR). If ventricular fibrillation is not reversed, 70J energy was delivered followed by CPR. Blood gas analysis, electrolyte and myocardium zymogram examination, cardiac function determination and neurological scores were measured at different time points after the animal was successfully resuscitated, and gross anatomy was performed at 72 hours later. MAIN OUTCOME MEASURES: Electrocardiogram (ECG), blood pressure, respiration, as well as body temperature was monitored in the process of experiment. ECG, blood gas, electrolyte, neurological scores and gross anatomy was examined prior to and after defibrillation. RESULTS: 86.7% animals were successful resuscitated by 50 J shocks and CPR; ST segment of ECG in some pigs were kept down or elevated, which returned to the baseline within a few minutes; Heart ejection fraction, and fractional area change in both two groups were significant decreased in 3-4 hours after defibrillation (P < 0.05), which returned to normal after 72 hours. There was no obvious haemodynamics difference prior to and after experiment (P > 0.05). No abnormal appearance could be found in neuroethology and gross anatomy. CONCLUSION: 50J-70J-70J energy biphasic defibrillations followed by CPR can achieve an excellent resuscitation effect on young Taihu pigs (7-25 kg) models of ventricular fibrillation.