兔乙醇胫神经干阻滞的量效关系研究

The research of dose-response relationship following alcohol-induced rabbits′ tibial nerve block

目的:明确兔乙醇胫神经阻滞的量效关系。方法:新西兰兔24只,胫神经44条,外周神经电刺激器引导下,行胫神经无水乙醇阻滞。按注射容量分为4组:0.1ml、0.3ml、0.5ml和1.0ml。分别于阻滞前和阻滞后第1、2、4、7天及2、3、4、5、6、7、8周,记录腓肠肌复合肌肉动作电位(CMAP);实验终止时,取胫神经和注射部位肌肉行HE染色,观察组织学损害。结果:小容量0.1ml组CMAP波幅在第1周有所恢复,但第2周作用基本消失(P>0.05),而0.3ml组的作用持续到第8周(P<0.05);大容量组(0.5ml和1.0ml)CMAP波幅降低更明显(P<0.05),但并发症也显著增加。大部分动物(9/15)因并发症死亡,故实验在第4周终止。前4周CMAP波幅降低,除0.3ml与0.5ml组间差异不显著(P>0.05),其他各组间差异显著(P<0.05);组织学示各组出现不同程度神经轴索变性;0.5ml和1.0ml组肌肉局灶性结缔组织增生。结论:兔乙醇胫神经干阻滞的理想有效安全容量是0.3ml/点。

Objective： To verify the dose-response relationship in alcohol-induced rabbits′ tibial nerve block. Method： Twenty-four New Zealand white rabbits were randomly assigned to four groups based on alcohol volume （0.1ml、0.3ml、0.5ml、1.0ml）. All tibial nerves were successfully located with a nerve electrical stimulator. Compound muscle action potential （CMAP） was measured on the skin surface of gastrocnemius muscle belly preintervention and at days 1, 2, 4, 7 and weeks 2, 3, 4, 5, 6, 7, 8 postblock. Histologic studies were performed to evaluate the destruction of tibial nerves and muscles. Result： In four groups, CMAP amplitude showed reduction 1 day after nerve block. In group 0.1ml, CMAP amplitude showed the smallest reduction at 1 day and recovered in 1 week after block, but the block effect disappeared at 2 week after block（P〉0.05）. In group 0.3ml, the block effect last 8 weeks. In groups 0.5ml and 1.0ml, CMAP amplitudes showed maximal reduction 1 day after block 4 weeks and no increase later. There was no statistically difference between groups 0.3ml and 0.5ml （P〈0.05）. Axonal degeneration was evident within the tibial nerve among all groups. Muscle desmoplasia was noted within the groups of 0.5ml and 1.0ml. Conclusion： The most effective and safest volume is 0.3ml for alcohol induced rabbits′ tibial nerve block.