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.
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The veterinary journal · Mar 2016
von Frey anesthesiometry to assess sensory impairment after acute spinal cord injury caused by thoracolumbar intervertebral disc extrusion in dogs.
Sensory threshold (ST) was measured using an electric von Frey anesthesiometer (VFA) in all limbs of 20 normal dogs and 29 dogs with acute thoracolumbar spinal cord injury (SCI) caused by spontaneous intervertebral disc extrusion. ST values were measured at three separate time points in normal dogs and on days 3, 10 and 30 following decompressive surgery in dogs with SCI. ST values were compared between groups and correlated with locomotor recovery in SCI-affected dogs. ⋯ A significant decline in ST values across testing sessions was observed for all limbs of normal and SCI-affected dogs and may be related to patient acclimation, operator training effect, or effect of analgesic medications. This study supports the feasibility of VFA to assess differences in ST between normal and SCI-affected dogs. However, future studies must focus on techniques to minimize or compensate for clinical, environmental and behavioral factors which may impact ST values in the clinical setting.