Analgesic efficacy of ultrasound-guided block of sciatic and femoral nerves in experimental sheep (Ultrasheep)

Background

Current anaesthesia protocol at the ARI for orthopaedic hindlimb surgery in sheep includes epidural anaesthesia. Possible complications with an epidural analgesia are urine retention, neural damage, neuritis and temporarily loss of motor function in both hindlimbs. Nevertheless, it is very important to use local analgesia in order to save on anaesthetics and thus reduce their side effects. Therefore, in this study we investigated another protocol for local analgesia: the peripheral nerve block. To provide local analgesia in the operated hind limb we performed an ultrasound-guided block of the sciatic and femoral nerve and compared the analgesic efficacy of the nerve blocks with the epidural analgesia.

Goal

Refinement of the current analgesia and anaesthesia protocol used in the ARI for sheep undergoing invasive surgery on one hind limb.

Results

Ultrasound-guided peripheral nerve block is a reliable technique in sheep. There was no difference in analgesic effect of epidural and peripheral nerve block. A benefit of the peripheral nerve block is the earlier return to mobility in the recovery period since only the operated leg is motorically restricted.