국소마취제의 주사후 발생하는 말초신경손상에 관한 실험적 연구

초록

The peripheral nerve is a common target of injection of local anesthetics. There has been significant increase in the use of local anesthetics at the operating theatre, or the field of control of pain. And the physicochemical properties of recently used local anesthetics are somewhat different from that of the earlier. So, the possibility of neural injury due to injection of the local anesthetics has increased but neglected due to its low incidence. There are some controversies about the neurotoxicity of local anesthetics. The author experimentally observed the morphological neuronal changes or neurotoxicity through light and electron microscope two weeks after the intraneural injection of 0.9% physiologic saline, 2% lidocaine HCl, and 0.5% bupivacaine HCl to rat sciatic nerve and compared the results with those of the perineural injection. The results are as follows : 1. In all the perineural injection groups. no morphological changes were observed. 2. In the intraneural injection groups, all cases showed the varying degrees of neural injury and some showed the findings that suggested of regeneration. 3. The observed findings of neural injury were axonal degeneration, segmentation of axon and myelin sheath, and phagocytotic Schwann cells and macrophages. 4. In all groups, there was no evidence of changes in the connective tissues of epineurium, perineurium, and endoneurium. 5. No specific difference was found between the neurotoxic effects of 2% lidocaine and 0.5% bupivacaine. In conclusion, if intraneural injection would be avoided, 2% lidocaine and 0.5% bupivacaine are safe local anesthetics to the peripheral nerves.