Department and Clinic of Equine Medicine, University of Veterinary Medicine, Budapest, Hungary.
Állatszemész, University of Veterinary Medicine, Budapest, Hungary.
Vet Anaesth Analg. 2021 Nov;48(6):972-976. doi: 10.1016/j.vaa.2021.04.008. Epub 2021 Jul 16.
To compare the corneal anaesthetic effect of 0.5% bupivacaine, 2% lidocaine and 0.4% oxybuprocaine on normal equine eyes.
Prospective, blinded crossover study.
A group of 10 clinically healthy horses.
Corneal sensitivity was determined in each eye by measuring corneal touch threshold (CTT). The study had three phases. Each subject was randomly given one of the three treatments followed by a 72 hour washout period. Every horse received all treatments. Baseline CTT was recorded prior to anaesthetic instillation (T0) then CTT was measured 5 and 10 minutes after (T1 and T2, respectively), then 20 to 90 minutes (T3 to T10) at 10 minute intervals. CTT data were compared among treatments at each time point using the Friedman test p < 0.05.
Median (range) baseline CTT was 51.3 (25.0-60.0) mm for bupivacaine, 50.0 (40.0-55.0) mm for oxybuprocaine and 55.0 (30.0-60.0) mm for lidocaine. All treatments caused a significant decrease in CTT at T1. The lowest CTT was observed at T3 with bupivacaine and oxybuprocaine treatments. Median CTTs at this time point were 18.7 (5.0-25.0) mm and 28.7 (25.0-40.0) mm, respectively. The lowest CTT with lidocaine treatment was 28.7 (20.0-50.0) mm at T6 (50 minutes). At T3, CTT was significantly lower with the bupivacaine treatment compared with oxybuprocaine and lidocaine treatments (p < 0.0074). There was no significant difference in CTT values between T1 and T6 for bupivacaine, between T1 and T7 for lidocaine, and between T1 and T8 for oxybuprocaine. Duration of the maximum effect was 45 minutes for the bupivacaine, 55 minutes for the lidocaine and 65 minutes for the oxybuprocaine treatment.
Administration of a 0.5% injectable solution of bupivacaine or a 2% lidocaine had similar anaesthetic effect to the commonly used oxybuprocaine. Therefore, they might be used as alternatives for corneal anaesthesia.
比较 0.5%布比卡因、2%利多卡因和 0.4%氧苯卡因对正常马角膜的麻醉效果。
前瞻性、双盲交叉研究。
一组 10 匹临床健康马。
通过测量角膜触觉阈值（CTT）来确定每只眼睛的角膜敏感性。该研究分为三个阶段。每匹马随机接受三种治疗方法中的一种，然后进行 72 小时的洗脱期。每匹马都接受了所有的治疗。在麻醉剂滴注前（T0）记录基础 CTT，然后在 5 分钟和 10 分钟后（T1 和 T2）测量 CTT，然后在 20 到 90 分钟（T3 到 T10）时每隔 10 分钟测量一次。在每个时间点，使用 Friedman 检验比较治疗之间的 CTT 数据（p<0.05）。
布比卡因的中位数（范围）基础 CTT 为 51.3（25.0-60.0）mm，氧苯卡因的中位数（范围）为 50.0（40.0-55.0）mm，利多卡因的中位数（范围）为 55.0（30.0-60.0）mm。所有治疗方法在 T1 时均显著降低 CTT。T3 时，布比卡因和氧苯卡因的 CTT 最低。此时的中位数 CTT 分别为 18.7（5.0-25.0）mm 和 28.7（25.0-40.0）mm。利多卡因治疗的最低 CTT 为 T6（50 分钟）时的 28.7（20.0-50.0）mm。在 T3 时，与氧苯卡因和利多卡因相比，布比卡因治疗的 CTT 显著降低（p<0.0074）。布比卡因在 T1 和 T6 之间、利多卡因在 T1 和 T7 之间以及氧苯卡因在 T1 和 T8 之间的 CTT 值无显著差异。布比卡因的最大效应持续时间为 45 分钟，利多卡因为 55 分钟，氧苯卡因为 65 分钟。
注射用 0.5%布比卡因或 2%利多卡因的给药具有与常用的氧苯卡因相似的麻醉效果。因此，它们可能被用作角膜麻醉的替代品。
