Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 300 West Drake Road, Fort Collins, Colorado 80523, USA (Simpson, Van Metre, Applegate, Johnson, Brooks, Mama); Department of Veterinary Pathobiology, Oklahoma State University Center for Veterinary Health Sciences, 114 McElroy Hall, Stillwater, Oklahoma 74078, USA (Taylor).
Can Vet J. 2022 Mar;63(3):269-274.
To determine whether a single 4-point regional nerve block using 2% lidocaine administered distal to the fetlock of sheep with a single distal limb lameness will result in analgesia of the digits.
Eighteen adult ewes with a single limb lameness originating from distal to the metacarpo/metatarsophalangeal joint were enrolled in the study.
Digital lameness was confirmed and scored based on clinical examination. Pain associated with digital lesions was assessed in triplicate using a pressure algometer to quantify mechanical nociceptive threshold. The same procedure was repeated on the contralateral limb as a control, and maximum force and time to response recorded. A 4-point regional nerve block was performed using 8 mL of 2% lidocaine. Mechanical nociception was again applied in triplicate to both limbs as described above, by a blinded investigator. Following appropriate medical treatment, the ewe was released and lameness scoring repeated.Median values for pressure and time to withdrawal were determined for affected and control limbs, and differences between pre- and post-lidocaine block measures were compared using Friedman's ANOVA test. The Wilcoxon Signed-Rank test was used to compare lameness score pre- and post-block. Statistical significance was set at α = 0.05.
Application of the 4-point block resulted in a change in pressure required to elicit withdrawal (F-value 17.7; < 0.0001) as well as time to withdrawal (F-value 20.4; < 0.0001), for the affected limb as compared to the control limb. Lameness scores decreased following the block (Signed-rank statistic 85.5; < 0.0001).
The 4-point nerve block resulted in anesthesia of the distal limb in sheep in this clinical model.
确定在羊的跗关节远端单次使用 2%利多卡因进行 4 点区域性神经阻滞是否会导致趾部镇痛。
18 只单肢跛行的成年母羊，跛行起源于掌/跖关节远端。
通过临床检查确认并评分数字跛行。使用压力测痛计重复 3 次评估与数字病变相关的疼痛，以量化机械伤害感受阈值。在对侧肢体上重复相同的程序作为对照，并记录最大力和反应时间。使用 8 毫升 2%利多卡因进行 4 点区域性神经阻滞。盲法研究者再次按照上述描述，对双侧肢体重复进行 3 次机械伤害感受测试。在适当的药物治疗后，将母羊释放并重复跛行评分。确定受影响和对照肢体的压力和撤回时间的中位数值，并使用 Friedman ANOVA 检验比较利多卡因阻滞前后的测量值差异。使用 Wilcoxon 符号秩检验比较阻滞前后跛行评分。统计学意义设为 α = 0.05。
与对照肢体相比，4 点阻滞应用于病变肢体时，引起撤回所需的压力（F 值 17.7；<0.0001）以及撤回时间（F 值 20.4；<0.0001）发生变化。阻滞后跛行评分降低（符号秩统计量 85.5；<0.0001）。
在该临床模型中，4 点神经阻滞导致羊的远端肢体麻醉。
