Is a Block of the Femoral and Sciatic Nerves an Alternative to Epidural Analgesia in Sheep Undergoing Orthopaedic Hind Limb Surgery? A Prospective, Randomized, Double Blinded Experimental Trial

Abstract

Peripheral nerve blocks are commonly used in human and veterinary medicine. The aim of the study was to compare the analgesic efficacy of a combined block of the femoral and sciatic nerves with an epidural injection of ropivacaine in experimental sheep undergoing orthopaedic hind limb surgery. Twenty-five sheep were assigned to two groups (peripheral nerve block; sciatic and femoral nerves (P); epidural analgesia (E)). In group P 10 mL ropivacaine 0.5% was injected around the sciatic and the femoral nerves under sonographic guidance and 10 mL NaCl 0.9% into the epidural space while in group E 10 mL ropivacaine 0.5% was injected into the epidural space and 10 mL NaCl 0.9% to the sciatic and the femoral nerves. During surgery, heart rate, respiratory rate and mean blood pressure were used as indicators of nociception. In the postoperative phase, nociception was evaluated every hour by use of a purposefully adapted pain score until the animal showed painful sensation at the surgical site. The mean duration of analgesia at the surgical wound was 6 h in group P and 8 h in group E. Mean time to standing was 4 h in group P and 7 h in group E. In conclusion time to standing was significantly shorter in group P while the duration of nociception was comparable in both groups. The peripheral nerve block can be used as an alternative to epidural analgesia in experimental sheep.

Multimodal analgesic technique in a peacock (Pavo cristatus) anaesthetised for orthopaedic surgery

“…The femoral-sciatic nerve block is a regional anaesthetic technique well described in small and farm animals. 7,[46][47][48][49][50] At present, few case reports have described this locoregional technique in different avian species: d'Ovidio et al described a nerve stimulator-guided femoral-sciatic nerve block in raptors undergoing surgical treatment of pododermatitis, while Trujanovic et al reported the same block in a duck undergoing surgical fixation of a tibiotarsal fracture guided by both ultrasound and nerve stimulator. In the present case, due to the small size of the animal, the ultrasonography visualisation of the femoral nerve was challenging, hence the decision of using the nerve stimulator.…”

“…In the present case, we opted for a multimodal analgesic approach, which included the use of an opioid in premedication, as discussed above, combined with a local anaesthetic technique and ketamine infusion. The femoral‐sciatic nerve block is a regional anaesthetic technique well described in small and farm animals 7,46–50 . At present, few case reports have described this locoregional technique in different avian species: d'Ovidio et al.…”

An Exploration of Analgesia Options for Australian Sheep

“…In biomedical research, various procedures including orthopaedic, reproductive, cardiac, and abdominal surgeries are performed on sheep [7][8][9]. The use of pain relief in these procedures can ensure better animal welfare and higher ethical standards, promote the Three Rs, and minimise potential impacts on research outcomes.…”

Evaluating the Efficacy of a Peripheral Nerve Simulator-Guided Brachial Plexus Block in Rabbits Undergoing Orthopaedic Surgery Compared to Systemic Analgesia

“…The use of locoregional anaesthesia techniques for various surgical procedures, now commonplace in dogs and cats, has been reported in other species, including sheep [6], calves [7], goats [8,9], and pigs [10,11]. Local nerve blocks may be performed blind or guided by electrical nerve stimulation or ultrasound.…”