INTRAOCULAR PRESSURE, MEAN ARTERIAL BLOOD PRESSURE AND PUPILLARY DIAMETER IN RABBITS ( (Oryctolagus cuniculus) ) SUBJECTED TO RETROBULBAR BLOCK WITH DIFFERENT ANESTHETIC PROTOCOLS

Abstract The aim of this study was to evaluate four protocols of loco regional anesthesia for ophthalmic procedures that could provide safety and life support, in addition to maintain intraocular pressure stable, with eye centralization and eyelid akinesia. 20 New Zealand rabbits were used to perform local anesthesia by retrobulbar block with four protocols: 2% lidocaine with epinephrine, 2% lidocaine without epinephrine associated with tramadol, 1% ropivacaine and bupivacaine 0.5 %. Each animal received an anesthetic volume of 1 mL. All anesthetic protocols used promoted eyelid akinesia and centralization of the eye during the assessment period. The retrobulbar block with the proposed anesthetic protocols proved to be feasible and safe for the maintenance of intraocular pressure, invasive blood pressure and pupillary diameter and can be used in intraocular surgeries, respecting the time of action of each anesthetic. All protocols showed an excellent blockage action but bupivacaine promoted the highest pupil diameter compared to the other drugs tested.

摘要 本研究旨在评估四种用于眼科手术的局部区域麻醉方案，以期在维持眼压稳定、实现眼球中心化与眼睑制动的同时，保障麻醉安全性并提供生命支持。本研究选用20只新西兰兔，采用四种方案行球后阻滞（retrobulbar block）麻醉：含肾上腺素的2%利多卡因、不含肾上腺素的2%利多卡因联用曲马多、1%罗哌卡因以及0.5%布比卡因。每只动物的麻醉给药体积为1 mL。所有受试麻醉方案均可在评估周期内实现眼睑制动与眼球中心化。结果证实，采用本研究所提出的球后阻滞麻醉方案，在维持眼压、有创血压及瞳孔直径方面均具备可行性与安全性，可应用于眼内手术，仅需遵循各麻醉药物的作用时长规范即可。所有受试方案均展现出优异的阻滞效果，但布比卡因所致的瞳孔直径大于其余受试药物。