Proximal RUMM block in dogs: preliminary results of cadaveric and clinical studies

Abstract

Objective To evaluate intra and postoperative efficacy of an ultrasound (US)-guided radial (R), ulnar (U), median (M) and musculocutaneous (Mc) nerve blocks, performed together in the axillary space by a single in-plane approach.Study design Anatomical research and prospective clinical study.Animals Three dog cadavers and 15 client-owned dogs undergoing thoracic orthopaedic limb surgery. MethodsIn Phase-1, anatomical dissection and US study of the axillary space were performed to design an US-guided proximal RUMM block.The technique was considered successful if 0.15 mL kg -1 of new methylene blue solution completely stained for ≥ 2 cm the four nerves in two cadavers.In Phase-2, the US-guided proximal RUMM block designed on phase 1 was performed as analgesic strategy in fifteen client-owned dogs undergoing orthopaedic thoracic limb surgery using a total volume of 0.15 mL kg -1 of ropivacaine 0.5%. Intraoperative success rate (fentanyl requirement < 1.2 mcg kg -1 hour -1 ) and analgesic duration of the block, by a postoperative pain score (Short form Glasgow composite measure pain scale, SF-GCMPS ≥ 5/20) were evaluated.

Lateral ultrasound-guided axillary RUMM block in cats: a pilot cadaveric study

“…Evidence for an axillary sheath surrounding the R, U, M and Mc nerves has recently been described in dogs. 8 Despite no visualisation of one in this study, its existence in the cat is plausible and may explain the variability in nerve stain characteristics between specimens, as well as the complete stain failures in specimens 5 and 7. In these specific specimens (5 and 7), injected solution between the triceps muscles indicate incorrect needle placement, possibly outside a fascial plane.…”

“…The current study describes a 20 mm target stain length, as do most cadaveric studies. 8,15,16 The dose rate of 0.2 ml/kg body weight was extrapolated from Campoy et al 15 and aimed to minimise the risks of collateral nerve staining when using larger volumes as documented by Anson et al 3 As with most cadaveric studies, major limitations to this study include undetected neurovascular damage and translating how nerve staining (block) relates to nerve desensitisation clinically. Using this modified lateral approach, theoretical damage may be possible to the axillary artery, its continuation as the brachial artery and the cranial and caudal circumflex arteries.…”

“…The current study describes a 20 mm target stain length, as do most cadaveric studies. 8,15,16 The dose rate of 0.2 ml/kg body weight was extrapolated from Campoy et al 15 and aimed to minimise the risks of collateral nerve staining when using larger volumes as documented by Anson et al 3…”

“…Targeting the R nerve first, followed by needle redirection towards the U, M and Mc nerve bundle; the authors concluded anatomical staining of all RUMM nerves was achievable, and the lateral approach may improve operator ease and potentially reduce myogenic and neurovascular trauma compared with traditional approaches. 5,7–9 To our knowledge, a lateral approach to an axillary RUMM block using a single injection site, without needle redirection, has not been described in cats.…”

Bloqueio de plexo braquial em canino: relato de caso / Canine brachial plexus block: case report

“…O restante da solução é aplicado lentamente para o bloqueio completo do plexo braquial opióides mu e kappa de rápida ação (<1-2 min), curta duração (20-30 min) e elevada potência, 100 vezes maior do que a da morfina (GRUBB et al, 2020). Em um estudo realizado (TAYARI et al, 2019), três dos 15 animais submetidos a cirurgias ortopédicas de membros torácicos, necessitaram de resgate analgésico, sendo assim aplicado fentanil…”