Standardizing the technique of radial, ulnar, musculocutaneous and median (RUMM) nerve block in dogs Asarudhin A.1,†, Raj H. Pushkin2, Nagarajan L.3, Ramani C.4 1MVSc Scholar, Department of Veterinary Surgery and Radiology, Madras Veterinary College, Tamilnadu Veterinary and Animal Sciences University, Chennai-600 051 (Tamil Nadu) 2Assistant Professor, Department of Veterinary Surgery and Radiology, Madras Veterinary College, Tamilnadu Veterinary and Animal Sciences University, Chennai-600 051 (Tamil Nadu) 4Professor and Head, Department of Veterinary Surgery and Radiology, Madras Veterinary College, Tamilnadu Veterinary and Animal Sciences University, Chennai-600 051 (Tamil Nadu) 3Professor and Head, Department of Clinics, Madras Veterinary College, Tamilnadu Veterinary and Animal Sciences University, Chennai-600 051 (Tamil Nadu) †Corresponding author; E-mail: asarudhin1994@gmail.com
Online Published on 20 May, 2023. Abstract The aim of this study was to evaluate an ultrasound-guided technique and the anatomical basis for radial, ulnar, musculocutaneous and median (RUMM) nerve block in dogs. The study was conducted in two phases. In phase 1, cadaver dissection (using 4 cadavers) for anatomical landmarks and ultrasound study of the axillary region were used to design and to perform the US-guided RUMM block. It was feasible to detect RUMM nerves using ultrasound. Success of this technique was considered based on the staining of all four nerves in cadavers by using 0.15 mL/kg of methylene blue solution for e” 2 cm. In phase 2 study, combined ultrasound/electrolocation-guided nerve blocks were performed sequentially. Orthopaedic thoracic limb surgery of eight client owned dogs underwent RUMM block, which was designed in phase 1, to provide analgesia by using 0.5% of ropivacaine (2 mg/kg body wt). Effectiveness of the block was considered when the rescue analgesic requirement was less during intraoperative period as well as postoperative pain score was d” 5/20 based on short form of Glasgow Composite Measure Pain Scale (SF-CGMPS). The roots of the RUMM and the axillary RUMM block were established by ultrasound in all eight dogs. The relationship between the four ventral nerve roots (C6, C7, C8, and T1) and the axillary vessels was confirmed by anatomical review. In 6/8 anaesthetized dogs, mean intraoperative opioid requirement was reduced and postoperatively, up to 8 hr all the 8 dogs had pain score of SF-GCMPS d” 5/20. The placement of local anaesthetic for the axillary RUMM using ultrasound-guided needle insertion was a precise procedure. The use of an in-plane needling approach of 0.5% ropivacaine at 2 mg/kg reduced the need of opioids during thoracic limb surgery, leading to postoperative analgesia for up to 8 hr after the peripheral nerve block was performed. Top Keywords Axillary sheath, Dogs, In-plane technique, Ultrasound guidance, RUMM block. Top |