Intraoperative antinociception and postoperative analgesia following epidural anesthesia versus femoral and sciatic nerve blockade in dogs undergoing stifle joint surgery

Abstract

To compare analgesic efficacy of preoperative epidural anesthesia with efficacy of femoral and sciatic nerve blockade in dogs undergoing hind limb orthopedic surgery. Prospective randomized blinded clinical study. 22 dogs requiring stifle joint surgery. Dogs were premedicated with acepromazine and morphine, and anesthesia was induced with diazepam and propofol and maintained with sevoflurane in oxygen. Prior to surgery, a combination of 1.0% lidocaine solution with 0.25% bupivacaine solution was administered either into the lumbosacral epidural space (11 dogs) or perineurally along the femoral and sciatic nerves (11). Intraoperative nociception was assumed if heart rate or systolic blood pressure increased by > 10% from baseline, in which case fentanyl (2 μg/kg [0.9 μg/lb], IV) was administered as rescue analgesia. Following recovery from anesthesia, signs of postoperative pain were assessed every 30 minutes for 360 minutes from the time of local anesthetic administration via the modified Glasgow pain scale. Patients with scores > 5 (scale, 0 to 20) received hydromorphone (0.1 mg/kg [0.05 mg/lb], IV) as rescue analgesia and were then withdrawn from further pain scoring. Treatment groups did not differ significantly in the number fentanyl boluses administered for intraoperative rescue analgesia. Time to administration of first postoperative rescue analgesia was comparable between groups. Furthermore, there was no significant difference between groups in baseline pain scores, nor were there significant differences at any other point during the postoperative period. Femoral and sciatic nerve blocks provided intraoperative antinociception and postoperative analgesia similar to epidural anesthesia in dogs undergoing stifle joint surgery.