Effects of intraperitoneal administration of bupivacaine on relief of pain and change of behavior following ovariohysterectomy in cats

Abstract

Perioperative pain relief is essential in veterinary practice. However, the cat is one of the most poorly understood species regarding pain control management. Ovariohysterectomy(OHE) produces considerable postoperative pain in cats. Practitioners are often reluctant to administer analgesics due to lack of familiarity with available drugs, concern about side effects, or frustration with the need for record keeping of controlled substances. The purpose of this study was to determine if intraperitoneal administration of bupivacaine can provide relief of pain following OHE in cats. Twelve healthy female cats were randomly divided into two groups. OHE was performed under general inhalation anesthesia. Just prior to complete closure of the linea alba, 6 cats in SAL group received 0.88 ml/kg 0.9% saline, 6 cats in BUP group received 4.4 mg/kg 0.75% bupivacaine diluted to an equivalent volume with saline in the intraperitoneal space. Cats were scored at 0, 1, 2, 4, 8, 12 and 24 hours post-extubation by one observer. Cats were evaluated using a visual analogue scale(VAS) and composite pain scale(CPS) that included physiologic variables. There were no significant differences in body weight, anesthesia time, surgery time, and incision length between the two groups. Cats in the BUP group had significantly(p < 0.05) lower VAS-pain scores than cats in the SAL group at 4, 8, 12 hours after surgery. Cats in the BUP group had significantly lower CPS scores than cats in the SAL group at 8, 12 hours after surgery. No adverse side effects were observed. These results support that the intraperitoneal administration of bupivacaine following OHE can be used for the prevention of postoperative pain and pain-induced behavioral changes in cats.