No abstract

OBJECTIVE This study aimed to determine whether an infiltrative block with liposomal bupivacaine was associated with less rescue analgesia administration and lower pain scores than a bupivacaine splash block after ovariohysterectomy in dogs. ANIMALS Eligible dogs included those that were spayed as part of a veterinary teaching laboratory. Dogs were up to 7 years old and otherwise healthy. A total of 136 dogs were analyzed. METHODS All dogs underwent ovariohysterectomy performed by veterinary students. Dogs received hydromorphone and acepromazine premedication, propofol induction, isoflurane maintenance, and an NSAID. Dogs were randomly allocated to receive either a splash block with standard bupivacaine or an infiltrative block with liposomal bupivacaine for incisional analgesia. Postoperatively, all dogs were assessed by a blinded evaluator using the Colorado State University–Canine Acute Pain Scale (CSU-CAPS) and Glasgow Composite Measures Pain Scale–Short Form (GCPS-SF). Dogs received rescue analgesia with buprenorphine if they scored ≥ 2 on the CSU-CAPS scale. RESULTS Dogs that received liposomal bupivacaine had a significantly lower incidence of (P = .04) and longer time to (P = .03) administration of rescue analgesia. There was an overall time-averaged significant difference between groups for CSU-CAPS (P = .049) and GCPS-SF scores (P = .015), with dogs in the bupivacaine group being more likely to have an elevated pain score at some point for both scales. CLINICAL RELEVANCE The use of liposomal bupivacaine in an infiltrative block may decrease the need for rescue analgesia in dogs undergoing ovariohysterectomy compared to a bupivacaine splash block.