COMPARISON OF 3 METHODS FOR RELIEF OF PAIN AFTER EAR CANAL ABLATION IN DOGS

This study compared three methods of pain relief in dogs that had tota l ear canal ablation with lateral bulla osteotomy. The hypothesis was that systemic opioids with preoperative local nerve blocks would provi de superior pain relief, Thirty-one dogs with chronic otitis externa w ere included in the study. Dogs were, randomly assigned to one of thre e protocols: systemic opioids alone (10 dogs, group 1), systemic opioi ds with bupivacaine splash block (11 dogs, group 2). and systemic opio ids with preoperative local bupivacaine nerve blocks (10 dogs, group 3 ). Twenty-one dogs had bilateral ear ablation and 10 had unilateral ab lation. Pain was assessed preoperatively, at extubation, 2 hours poste xtubation, and 1 day postoperatively by a single observer blinded to t he analgesic protocol used. Pain scores were not significantly differe nt within or between groups, nor did unilateral versus bilateral ablat ion have a significant effect on the scare, Mean scores were less than 3 (scale 1 to 5) for all groups at all observation times, Rough recov eries were noted in 30% of group 1 dogs, 0% of group 2, and 20% of gro up 3 dogs. Ninety-four percent of dogs were moderately to heavily seda ted at extubation. Sixty percent of group 3 dogs remained moderately t o heavily sedated 2, hours postextubation. Rectal temperature, pulse r ate, respiratory rate, and postoperative change in serum cortisol leve ls were not significantly different between groups. Postoperative incr ease in blood glucose was significantly higher in groups 1 and 3 compa red with preoperative levels. Twenty-three percent of the dogs require d additional analgesia or tranquilization after surgery, as determined by the anesthetist; 1 dog in group 1, 2 in group 2, and 4 in group 3. Each of the three analgesic protocols provided similar pain relief in dogs undergoing total ear canal ablation. (C) Copyright 1996 by The A merican College of Veterinary Surgeons