球周局部麻醉对兔眼视网膜电图的影响

Effects of peribulbar anesthetics on electroretinogram of rabbit

目的比较不同剂量局部麻醉药球周麻醉对视网膜电图(ERG)的影响。方法18只家兔随机分为3组:1.5、1.0、0.5mL组,每组右眼注射局部麻醉药物作为麻醉眼,左眼注射等量的生理盐水作为对照眼。采用RETIport32-scan系统和角膜接触镜电极分别记录注药前和注药后5、30、60、90、120min暗适应ERG及震荡电位。每观察点间行20min暗适应。结果麻醉眼ERGb波和OPs波OP2幅值均呈下降趋势;1.5mL组和1.0mL组b波幅值在90min时下降明显,与注药前相比差异有统计学意义(P=0.004、0.046);1.5mL组OP2幅值在90min时下降明显,差异有统计学意义(P=0.042)。对照眼b波、OP2幅值初始呈轻微下降趋势,1.5mL组和1.0mL组30min下降明显,但差异均无统计学意义(P>0.05)。麻醉眼注药剂量与ERGb波和OP2振幅的变化无明显线性相关(P>0.05)。结论不同剂量局部麻醉药物球周麻醉后短时间内均可引起ERGb波和OPs波OP幅值的变化。

Objective This study was designed to investigate the effects of perihulbar anesthetics on electroretinogram of rabbit. Methods Eighteen healthy adult Chinese white rabbits were randomly assigned to three groups and 6 rabbits for each group. 1.5,1.0,0.5 mL of mixture with 2% Lidoeaine and 0.75% Bupivacaine was injected via peribulhar in the right eyes,and the left eyes of each rabbit received the same volume of 0. 9% normal saline solution as control. The h wave and oscillatory potentials（OPs） of scotopic electroretinogram（ERG） were recorded with RETIport32-scan system and contact lens eleetrods in 5, 30,60,90 and 120 minutes after injection. The recording procedure followed the ERG International Standard Protocol. Results The b wave amplitudes of scotopic ERG maxmum response showed a downward value in peribulbar anesthesia eyes with the more reducing values in 1.5 mL group and 1.0 mL group at 90 minutes after injection（P = 0. 004,0. 046 respectively） , and the decline value of OP2 amplitude was significant in 90 minutes after injection（P = 0. 042）. In control eyes,the amplitudes of ERG b wave and OP2 displayed an insignificant decline in various time points after injection of normal saline solution （ P 〉 0. 05 ）. No significant correlation was found between the dosage of anesthesia medication and ERG change （r = -0. 612, P = 0. 074 ）. Conclusion Different doses of local anesthetics can cause the change of the amplitude of ERG b wave and OP2 in short-term duration.