The veterinary journal
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The veterinary journal · Mar 2016
Randomized Controlled TrialThe effect of loco-regional anaesthesia on motor activity induced by direct stimulation of the sciatic nerve in dogs.
A prospective, randomised, blinded, case-controlled clinical study was designed using client-owned dogs undergoing unilateral pelvic limb orthopaedic surgery, to determine the effect on induced motor activity by electrical stimulation of the sciatic nerve distal to the site of local anaesthetic administration. Dogs were administered 0.5% bupivacaine either extradurally or via a femoral and transgluteal sciatic electrolocation-guided nerve block prior to pelvic limb surgery. Motor response to electrical stimulation of branches of the sciatic nerve was tested and the minimum current required to induce muscle twitch was recorded prior to bupivacaine administration. ⋯ There was no significant difference in the minimum current required to induce muscle twitch between pre- and post-operative testing (P = 0.31 sciatic site, P = 0.36 peroneal site), nor between the two groups using different loco-regional anaesthetic techniques (minimum P = 0.13). This study shows that stimulation of the sciatic nerve distal to the site of bupivacaine administration induces motor activity, despite adequate sensory blockade. This is relevant in surgical cases where mechanical stimulation of the sciatic nerve might be expected and needs to be recognised to avoid postoperative neurapraxia.