Impact of epidural bupivacaine on perioperative opioid requirements, recovery characteristics, and duration of hospitalization in dogs undergoing cystotomy: A retrospective study of 56 cases.

OBJECTIVE To compare perioperative opioid consumption and duration of hospitalization (DOH) in anesthetized dogs receiving opioid-based analgesia (OBA) vs those receiving bupivacaine epidural-based analgesia (EPID) during cystotomy. STUDY DESIGN Retrospective cross-sectional study. ANIMALS Fifty-six client-owned dogs undergoing cystotomy. METHODS Clinical records of dogs undergoing cystotomy between January 2015 and December 2017 were reviewed. Demographic data, duration of anesthesia and surgery, anesthetic management, perioperative opioid consumption expressed in morphine equivalents (ME), perioperative use of adjuvant analgesics, time to first micturition, time to eat, time to ambulate, and DOH were recorded. Opioid consumption and DOH were compared with a Wilcoxon rank-sum test, followed by linear regression analysis as appropriate. Time to first micturition, time to eat, and time to walk unassisted were modeled with Cox-proportional hazard models. RESULTS Dogs treated with EPID during surgery required 1.5 mg/kg ME less compared with those treated with OBA (P = .04) during surgery. Three of 19 dogs treated with EPID vs 15 of 37 dogs receiving OBA required intraoperative adjuvant analgesics (P = .06). Dogs treated with EPID regained motor function slower than dogs treated with OBA (P = .01); however, there was no difference in time to urinate, time to eat, or DOH between treatments. CONCLUSION Perioperative lumbosacral epidural with bupivacaine reduced intraoperative opioid consumption in dogs anesthetized for cystotomy. CLINICAL SIGNIFICANCE The use of epidural bupivacaine in dogs undergoing cystotomy may reduce intraoperative opioid requirements without affecting return of bladder function or DOH.