Assessment of the epidural distribution of sequential boluses of iohexol injected at the sacrococcygeal space in anesthetized cats.

IF 1.3 3区农林科学 Q2 VETERINARY SCIENCES

American journal of veterinary research Pub Date : 2025-07-08 DOI:10.2460/ajvr.25.03.0107

Shanna Wong, Jordyn M Boesch, Stephen Parry, Robin D Gleed, Manuel Martin-Flores, Ian Porter

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引用次数: 0

Abstract

Objective: To determine the distribution of injectate (iohexol) at the feline sacrococcygeal space using CT and thereby identify the volume necessary to reach the 10th thoracic intervertebral foramina (T10-T11), where nociceptive neurons from the ovaries enter the spinal cord.

Methods: 7 healthy, purpose-bred, 1- to 2-year-old intact female domestic shorthair cats were anesthetized and positioned in sternal recumbency. After baseline vertebral column CT, a stimulating needle connected to a nerve stimulator (current, 0.2 mA; frequency, 2 Hz; pulse width, 0.1 milliseconds) was inserted at the sacrococcygeal space. After distal tail twitching was observed, a syringe driver injected iohexol (44 mg/mL; 0.25 mL/kg over 30 seconds). Computed tomography was performed 30 seconds after the injection ended. This was repeated 3 times, with 4 minutes separating the start of each injection. A linear mixed-effects model was constructed to determine if the number of vertebrae traversed as the iohexol distributed cranially could be predicted as a function of injectate volume, side of vertebral column, and their interaction (cat as a random effect).

Results: The association between injectate volume and number of vertebrae traversed was significant. The volume required to reach the T10-T11 intervertebral foramen bilaterally was 0.75 mL/kg in 3 cats and 1.0 mL/kg in 3 cats; in 1 cat, 1.0 mL/kg did not reach this level.

Conclusions: Sacrococcygeal epidural injection of 0.75 to 1.0 mL/kg or more of local anesthetic may be required for segmental analgesia for feline ovariohysterectomy.

Clinical relevance: The volume required is greater than the volume injected epidurally in previous studies and could increase the risk of producing hemodynamic side effects.

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麻醉猫骶尾骨间隙连续注射碘己醇硬膜外分布的评价。

目的：利用CT确定注射（碘hexol）在猫骶尾骨间隙的分布，从而确定到达第10胸椎间孔（T10-T11）所需的体积，从卵巢的伤害性神经元进入脊髓。方法：选取7只健康、1 ~ 2岁的纯种母短毛猫，麻醉后置于胸骨平卧位。基线脊柱CT后，将刺激针连接到神经刺激器(电流，0.2 mA；频率：2hz；脉冲宽度，0.1毫秒)插入骶尾骨间隙。观察到尾巴远端抽搐后，用注射器驱动器注射碘己醇(44 mg/mL；0.25 mL/kg，超过30秒)。注射结束后30秒进行计算机断层扫描。重复3次，每次注射间隔4分钟。建立了一个线性混合效应模型，以确定碘hexol在颅脑分布时穿过的椎骨数量是否可以作为注射量、脊柱侧位及其相互作用的函数来预测（cat为随机效应）。结果：注射量与穿过的椎体数量有显著的相关性。3只猫到达双侧T10-T11椎间孔所需的体积为0.75 mL/kg， 3只猫为1.0 mL/kg；1只猫1.0 mL/kg未达到这一水平。结论：骶尾骨硬膜外注射0.75 ~ 1.0 mL/kg以上的局麻药可用于猫卵巢子宫切除术的节段性镇痛。临床相关性：所需的体积大于以往研究中硬膜外注射的体积，并可能增加产生血流动力学副作用的风险。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

American journal of veterinary research 农林科学-兽医学

CiteScore

1.70

自引率

10.00%

发文量

186

审稿时长

3 months

期刊介绍： The American Journal of Veterinary Research supports the collaborative exchange of information between researchers and clinicians by publishing novel research findings that bridge the gulf between basic research and clinical practice or that help to translate laboratory research and preclinical studies to the development of clinical trials and clinical practice. The journal welcomes submission of high-quality original studies and review articles in a wide range of scientific fields, including anatomy, anesthesiology, animal welfare, behavior, epidemiology, genetics, heredity, infectious disease, molecular biology, oncology, pharmacology, pathogenic mechanisms, physiology, surgery, theriogenology, toxicology, and vaccinology. Species of interest include production animals, companion animals, equids, exotic animals, birds, reptiles, and wild and marine animals. Reports of laboratory animal studies and studies involving the use of animals as experimental models of human diseases are considered only when the study results are of demonstrable benefit to the species used in the research or to another species of veterinary interest. Other fields of interest or animals species are not necessarily excluded from consideration, but such reports must focus on novel research findings. Submitted papers must make an original and substantial contribution to the veterinary medicine knowledge base; preliminary studies are not appropriate.