Comparison of medial and lateral ultrasound-guided approaches to radial, ulnar, median, and musculocutaneous (RUMM) nerve injections in rats

IF 2.5 2区农林科学 Q2 VETERINARY SCIENCES

Veterinary anaesthesia and analgesia Pub Date : 2026-03-01 Epub Date: 2025-12-26 DOI:10.1016/j.vaa.2025.101172

Douglas Castro , Andre Escobar , Nassim Bouhabib , Stuart C. Clark-Price , Erik H. Hofmeister

{"title":"Comparison of medial and lateral ultrasound-guided approaches to radial, ulnar, median, and musculocutaneous (RUMM) nerve injections in rats","authors":"Douglas Castro , Andre Escobar , Nassim Bouhabib , Stuart C. Clark-Price , Erik H. Hofmeister","doi":"10.1016/j.vaa.2025.101172","DOIUrl":null,"url":null,"abstract":"<div><h3>Objective</h3><div>To compare the length staining of the radial, ulnar, median, and musculocutaneous nerves (RUMM) in rat cadavers using one of two ultrasound-guided injection approaches: medial (MA) and lateral (LA).</div></div><div><h3>Study design</h3><div>Prospective, experimental, randomized cadaveric study.</div></div><div><h3>Animals</h3><div>A group of ten frozen-thawed adult Wistar rat cadavers.</div></div><div><h3>Methods</h3><div>Ultrasound-guided proximal RUMM injections were performed using a volume of 0.1 mL of a bupivacaine-dye solution, divided between two injection sites: within the neurovascular sheath [radial, ulnar, and median (RUM) nerves] and near the musculocutaneous nerve. For LA (<em>n</em> = 10 rats, 10 limbs), a linear transducer was positioned over the triceps region at the proximal third of the <em>brachium</em>, oriented perpendicular to the humerus’s longitudinal axis, with the needle advanced from caudal to cranial. For MA (<em>n</em> = 10 rats, 10 limbs), the transducer was aligned perpendicular to the proximal humeral head, with the needle introduced from caudal to cranial. Anatomical dissections were performed and length of nerve staining was measured. Data were analyzed using paired two-tailed <em>t</em>-tests for parametric data with significance set at <em>p</em> < 0.05.</div></div><div><h3>Results</h3><div>In both approaches, complete staining of RUM nerves within the neurovascular sheath was achieved. The MA resulted in significantly greater dye spread (10.4 ± 1.0 mm) than the LA (6.7 ± 1.7 mm, 95% confidence interval 2.1–5.3) (<em>p</em> < 0.001). All musculocutaneous nerves were stained in MA {5.0 mm [interquartile range (IQR): 4.8–6.0 mm]}, while one nerve was unstained in LA [5.5 mm (IQR: 5.0–6.0 mm)], with no observable differences between them.</div></div><div><h3>Conclusions and clinical relevance</h3><div>The MA achieved greater dye spread length along the RUM nerves and similar spread length of the musculocutaneous nerve compared with the LA. Further studies are necessary to assess the application in live rats.</div></div>","PeriodicalId":23626,"journal":{"name":"Veterinary anaesthesia and analgesia","volume":"53 2","pages":"Article 101172"},"PeriodicalIF":2.5000,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Veterinary anaesthesia and analgesia","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S146729872500279X","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/12/26 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"VETERINARY SCIENCES","Score":null,"Total":0}

引用次数: 0

Abstract

Objective

To compare the length staining of the radial, ulnar, median, and musculocutaneous nerves (RUMM) in rat cadavers using one of two ultrasound-guided injection approaches: medial (MA) and lateral (LA).

Study design

Prospective, experimental, randomized cadaveric study.

Animals

A group of ten frozen-thawed adult Wistar rat cadavers.

Methods

Ultrasound-guided proximal RUMM injections were performed using a volume of 0.1 mL of a bupivacaine-dye solution, divided between two injection sites: within the neurovascular sheath [radial, ulnar, and median (RUM) nerves] and near the musculocutaneous nerve. For LA (n = 10 rats, 10 limbs), a linear transducer was positioned over the triceps region at the proximal third of the brachium, oriented perpendicular to the humerus’s longitudinal axis, with the needle advanced from caudal to cranial. For MA (n = 10 rats, 10 limbs), the transducer was aligned perpendicular to the proximal humeral head, with the needle introduced from caudal to cranial. Anatomical dissections were performed and length of nerve staining was measured. Data were analyzed using paired two-tailed t-tests for parametric data with significance set at p < 0.05.

Results

In both approaches, complete staining of RUM nerves within the neurovascular sheath was achieved. The MA resulted in significantly greater dye spread (10.4 ± 1.0 mm) than the LA (6.7 ± 1.7 mm, 95% confidence interval 2.1–5.3) (p < 0.001). All musculocutaneous nerves were stained in MA {5.0 mm [interquartile range (IQR): 4.8–6.0 mm]}, while one nerve was unstained in LA [5.5 mm (IQR: 5.0–6.0 mm)], with no observable differences between them.

Conclusions and clinical relevance

The MA achieved greater dye spread length along the RUM nerves and similar spread length of the musculocutaneous nerve compared with the LA. Further studies are necessary to assess the application in live rats.

查看原文本刊更多论文

大鼠桡骨、尺骨、正中、肌皮（RUMM）神经注射的内侧和外侧超声引导入路比较。

目的：比较超声引导下两种注射方式（内侧（MA）和外侧（LA））对大鼠尸体桡骨、尺骨、正中神经和肌皮神经（RUMM）的长度染色效果。研究设计：前瞻性、实验性、随机尸体研究。动物：一组10只冻融的成年Wistar大鼠尸体。方法：超声引导下进行RUMM近端注射，使用体积为0.1 mL的布比卡因染料溶液，在两个注射部位进行注射：神经血管鞘内[桡、尺、正中（RUM）神经]和肌肉皮神经附近。对于LA （n = 10只大鼠，10条肢体），在肱近三分之一的肱三头肌区域放置一个线性换能器，方向垂直于肱骨纵轴，针从尾骨向颅骨推进。对于MA （n = 10只大鼠，10条肢体），换能器垂直于肱骨近端头部，针从尾端插入颅骨。进行解剖解剖，测量神经染色长度。参数资料采用配对双尾t检验，显著性p < 0.05。结果：两种入路均实现了神经血管鞘内RUM神经的完全染色。MA导致的染色扩散（10.4±1.0 mm）明显大于LA(6.7±1.7 mm， 95%可信区间2.1 ~ 5.3)（p < 0.001）。所有肌皮神经均在MA {5.0 mm[四分位间距（IQR）： 4.8-6.0 mm]}染色，1条神经未在LA [5.5 mm (IQR: 5.0-6.0 mm)]染色，两者之间无明显差异。结论及临床意义：与LA相比，MA在RUM神经上的染色扩散长度更大，在肌皮神经上的扩散长度相似。对其在活体大鼠中的应用进行进一步的研究是必要的。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Veterinary anaesthesia and analgesia 农林科学-兽医学

CiteScore

3.10

自引率

17.60%

发文量

审稿时长

97 days

期刊介绍： Veterinary Anaesthesia and Analgesia is the official journal of the Association of Veterinary Anaesthetists, the American College of Veterinary Anesthesia and Analgesia and the European College of Veterinary Anaesthesia and Analgesia. Its purpose is the publication of original, peer reviewed articles covering all branches of anaesthesia and the relief of pain in animals. Articles concerned with the following subjects related to anaesthesia and analgesia are also welcome: the basic sciences; pathophysiology of disease as it relates to anaesthetic management equipment intensive care chemical restraint of animals including laboratory animals, wildlife and exotic animals welfare issues associated with pain and distress education in veterinary anaesthesia and analgesia. Review articles, special articles, and historical notes will also be published, along with editorials, case reports in the form of letters to the editor, and book reviews. There is also an active correspondence section.