利多卡因布比卡因对兔视神经毒性的电镜观察

Optic nerve toxicity following retrobulbar application of 2% lidocaine and 0.75% bupivacaine in rabbits

目的观察2%利多卡因及0.75%布比卡因二者单独应用及联合应用,对兔视神经的毒性作用。方法10只正常新西兰兔随机等分为正常对照组、生理盐水组、利多卡因组、布比卡因组和利多卡因+布比卡因组5个组,每组2只兔(4眼)。正常对照组不作任何处理;生理盐水组、利多卡因组、布比卡因组分别球后注射生理盐水、2%利多卡因或0.75%布比卡因各1 mL,利多卡因+布比卡因组球后注射2%利多卡因和0.75%布比卡因各1 mL。注射后观察眼部表现并于注射后48 h取出视神经作透射电镜检查。结果所有兔均未出现注射并发症;2%利多卡因、0.75%布比卡因均能导致兔视神经发生脱髓鞘现象以及轴突水肿,两药联合组最为显著。结论2%利多卡因及0.75%布比卡因球后注射对兔视神经均具有轻度的毒性作用,且可能具有相加或协同作用。

Objective To investigate the optic nerve toxicity following retrobulbar application of 2% lidocaine and 0.75% bupivacaine in rabbits. Methods Ten normal rabbits were averagely and randomly divided into five groups as follows： normal control group, normal saline group, lidocaine group,bupivacaine group, lidocaine united with bupivacaine group, each consisting two rabbits （four eyes）. No operation was applied to normal control group, but we injected retrobulbarly 1.0 ml normal saline, 2% lidocaine and 0.75% bupivacaine into normal saline group, lidocaine group, bupivacaine group, respectively. To lidocaine united with bupivacaine group, we applied retrobulbarly 1.0 milliliter 2% lidocaine and 0.75% bupivacaine, respectively. Performances in eyes were observed at 24h and 48h, and all rabbits were sacrificed for electron microscopy of optic nerve at 48h postoperatively. Results No significant complications were observed. Both 2% lidocaine and 0.75% bupivacaine could demyelinate optic nerve, especially when administered together. Conclusions Not only 2% lidocaine or 0.75% bupivacaine presents toxic effects on optic nerve but they may have synergistic effects.