Objective

To assess the analgesic effects of a retrobulbar block with ropivacaine in dogs undergoing enucleation.

Study design

Prospective, randomized, masked placebo-controlled trial.

Animals

A total of 23 client-owned dogs.

Methods

Dogs were randomized to be administered a preoperative inferior-temporal palpebral retrobulbar injection of either ropivacaine 0.75% (1 mL 10 kg^–1; group RG) or equivalent volume of 0.9% saline (control; group CG). Intraoperative variables recorded to detect a response to noxious stimuli included heart rate (HR) and mean arterial pressure (MAP). Three observers assessed and recorded pain using a numerical rating pain scale and visual analog scale (VAS) before anesthesia (baseline) and postoperatively at 0, 0.5, 1, 2, 3, 4, 5, 6 and 24 hours after extubation. Rescue analgesia was administered if intraoperative HR or MAP increased by ≥ 20% from the previously recorded surgical time point, average postoperative pain scores totaled ≥ 9/20, scored ≥ 3/4 in any one category with VAS $\ge$ 35/100, or if VAS was ≥ 35/100 with a palpation score > 0/4.

Results

Intraoperatively, there was no significant difference in HR or MAP between groups. Rescue analgesia was administered intraoperatively to four and one dogs and postoperatively to five and seven dogs in groups CG and RG, respectively, with no significant difference between groups. VAS scores were significantly lower in ropivacaine dogs at extubation (p = 0.02), but not at other postoperative time points. Adverse events were not observed in either group.

Conclusions and clinical relevance

Preoperative retrobulbar 0.75% ropivacaine injection (1 mL 10 kg⁻¹) provided analgesia in dogs following enucleation at extubation; however, intraoperative and postoperative pain control did not differ from a placebo injection with saline. Lack of differences between groups may have been influenced by sample size limitations.

中文翻译：

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0.75% 罗哌卡因球后阻滞对犬去核的镇痛作用

客观的

评估球后阻滞与罗哌卡因对接受去核的狗的镇痛作用。

学习规划

前瞻性、随机、蒙面安慰剂对照试验。

动物

共有 23 只客户拥有的狗。

方法

狗被随机分配接受术前下颞下睑球后注射 0.75% 罗哌卡因（1 mL 10 kg ^–1；RG 组）或等效体积的 0.9% 生理盐水（对照组；CG 组）。为检测对有害刺激的反应而记录的术中变量包括心率 (HR) 和平均动脉压 (MAP)。三名观察员在麻醉前（基线）和术后 0、0.5、1、2、3、4、5、6 和 24 小时使用数字评分疼痛量表和视觉模拟量表 (VAS) 评估和记录疼痛。如果术中 HR 或 MAP 较之前记录的手术时间点增加 ≥ 20%，术后平均疼痛评分总计 ≥ 9/20，VAS 任一类别评分≥ 3/4，则给予抢救性镇痛$\ge$35/100，或者如果 VAS ≥ 35/100 且触诊评分 > 0/4。

结果

术中，组间 HR 或 MAP 无显着差异。CG组和RG组分别在术中对4只和1只狗以及对5和7只狗进行术后镇痛，组间没有显着差异。罗哌卡因犬拔管时的 VAS 评分显着降低 ( p  = 0.02)，但在其他术后时间点则没有。两组均未观察到不良事件。

结论和临床相关性

术前球后注射 0.75% 罗哌卡因 (1 mL 10 kg ^-1 ) 在拔管时摘除犬后提供镇痛作用；然而，术中和术后疼痛控制与盐水安慰剂注射没有区别。组之间缺乏差异可能受到样本量限制的影响。