Schmidt S H, Hellström S, Anniko M
Department of Otorhinolaryngology and Head and Neck Surgery, University of Umeå, Sweden.
Arch Otorhinolaryngol. 1988;245(3):136-41. doi: 10.1007/BF00464014.
A eutectic mixture of two anesthetic solutions is that of lidocaine and prilocaine, which is available commercially as Emla (eutectic mixture of local anesthetics). This solution is commonly used in clinics in superficial skin surgery and when inserting intravenous catheters, and we also wanted to determine its surface effects when applied onto the tympanic membranes (TM) of rats and guinea pigs as animal models. The animals were observed by otomicroscopy for 2 weeks up to 5 months after administrations of the anesthetic solution. Tissue specimens were then obtained for light microscopy and fine structural analysis. The application of Emla caused minor structural changes to the rat TM, but hardly any alterations to that of the guinea pig. The changes displayed were an overall increased thickness, with typical submucosal edema but only slight epithelial reaction. In comparison with previous results with lidocaine, phenol and Bonain's solution, Emla seemed to be harmless to the structure of the TM. However, the efficacy of Emla as a topical TM anesthetic remains to be proved in future clinical trials.
两种麻醉剂溶液的共晶混合物是利多卡因和丙胺卡因的混合物，其作为复方利多卡因乳膏（局部麻醉剂的共晶混合物）在市场上有售。该溶液常用于临床浅表皮肤手术和插入静脉导管时，我们还想确定其应用于大鼠和豚鼠鼓膜（TM）作为动物模型时的表面效应。在给予麻醉剂溶液后，通过耳显微镜观察动物2周，长达5个月。然后获取组织标本进行光学显微镜检查和精细结构分析。复方利多卡因乳膏的应用对大鼠TM造成了轻微的结构变化，但对豚鼠TM几乎没有任何改变。所显示的变化是整体厚度增加，伴有典型的粘膜下水肿，但只有轻微的上皮反应。与之前使用利多卡因、苯酚和博纳因溶液的结果相比，复方利多卡因乳膏似乎对TM的结构无害。然而，复方利多卡因乳膏作为局部TM麻醉剂的疗效仍有待未来临床试验证实。
