目的:比较0.5%布比卡因的角膜麻醉效果,2%利多卡因和0.4%奥布卡因对正常马眼的影响。
方法:前瞻性,盲法交叉研究。
方法:一组10匹临床健康的马。
方法:通过测量角膜接触阈值(CTT)来确定每只眼睛的角膜敏感性。研究分为三个阶段。每个受试者被随机给予三种治疗中的一种,随后是72小时的清除期。每匹马都接受了所有的治疗。在麻醉滴注前(T0)记录基线CTT,然后在5和10分钟后(分别为T1和T2)测量CTT。然后以10分钟的间隔20至90分钟(T3至T10)。使用Friedman检验p<0.05比较各时间点的处理之间的CTT数据。
结果:布比卡因的基线CTT中位数(范围)为51.3(25.0-60.0)mm,奥布卡因为50.0(40.0-55.0)mm,利多卡因为55.0(30.0-60.0)mm。所有处理均导致T1时CTT显著降低。在T3时布比卡因和奥布卡因治疗观察到最低CTT。此时的CTT中位数分别为18.7(5.0-25.0)mm和28.7(25.0-40.0)mm,分别。利多卡因治疗的最低CTT在T6(50分钟)时为28.7(20.0-50.0)mm。在T3时,与奥布卡因和利多卡因治疗相比,布比卡因治疗的CTT明显降低(p<0.0074)。对于布比卡因,T1和T6之间的CTT值没有显着差异,利多卡因在T1和T7之间,T1和T8之间为奥布卡因。布比卡因的最大作用持续时间为45分钟,利多卡因治疗55分钟,奥布卡因治疗65分钟。
结论:给予0.5%布比卡因注射液或2%利多卡因与常用的奥布卡因具有相似的麻醉效果。因此,它们可能被用作角膜麻醉的替代品。
OBJECTIVE: To compare the corneal anaesthetic effect of 0.5% bupivacaine, 2% lidocaine and 0.4% oxybuprocaine on normal equine eyes.
METHODS: Prospective, blinded crossover study.
METHODS: A group of 10 clinically healthy horses.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.