Evaluation of targeted bupivacaine for reducing acute postoperative pain in cats undergoing routine ovariohysterectomy

Abstract

Objectives This study sought to determine if bupivacaine targeted at specific, potentially painful sites could enhance postoperative analgesia in routine feline ovariohysterectomies. A secondary objective was to assess the utility of multiple acute pain scales for cats in a high-volume surgery setting. Methods Two hundred and twelve cats were included in a prospective, randomized, double-blinded, placebo-controlled clinical trial. Anesthesia included buprenorphine, ketamine, dexmedetomidine and isoflurane. A ventral midline ovariohysterectomy was performed and cats were administered bupivacaine (2 mg/kg), placebo control (0.9% saline) or sham control (observation only) intraoperatively at the ovarian suspensory ligaments and vessels, uterine body and incisional subcutaneous tissues. Two pain scales were used to assess cats postoperatively. Initially, a multidimensional composite pain scale (MCPS) and a 0–10 numeric pain rating scale (NRS) were used. Subsequently, the MCPS was replaced with a modified Colorado State University Feline Acute Pain Scale (mCSU). Pain scores for the test groups were compared using a one-way ANOVA and a Holm–Bonferroni post hoc analysis when a difference was found ( P <0.05). Results Pain for the bupivacaine group was lower than the control groups at 1 h post-recovery and discharge, attaining significance with higher body weights. The P values were 0.008 and 0.004 for 1 h post-recovery and discharge, respectively. Pain scores between evaluators for the MCPS and NRS correlated poorly with r values for 1 h post-recovery and discharge of −0.08 and 0.22, respectively. Additionally, the MCPS proved difficult to use and time consuming, especially for feral and fractious patients, and was replaced with the mCSU. Conclusions and relevance Targeted bupivacaine reduced early postoperative pain scores following routine feline ovariohysterectomies. The technique used was simple, requiring just over a minute to perform at minimal additional cost. The MCPS was not ideal for use in a high-volume spay setting.

Comparison of perioperative analgesia using the infiltration of the surgical site with ropivacaine alone and in combination with meloxicam in cats undergoing ovariohysterectomy

“…However, the present study differs from these previous reports because, besides the midline incision site, the local anesthetic was also infiltrated in other anatomical areas involved in the surgical trauma caused by ovariohysterectomy, including the ovarian pedicles and the uterine cervix. Fudge et al [8] used a similar technique of tissue infiltration with bupivacaine and found low postoperative pain scores in cats undergoing ovariohysterectomy. Similarly, intraperitoneal instillation of bupivacaine or bupivacaine-dexmedetomidine on each ovarian pedicle and caudal uterus provided effective postoperative analgesia after ovariohysterectomy in cats [4,21].…”

“…Electrocardiography (lead II), heart rate (HR), oxyhemoglobin saturation (SpO 2 %), and esophageal temperature were continuously measured using a multi-parameter monitor 8 (DX 2020, Dixtal Biomédica Ind. Com.…”

“…Infiltration of the surgical site with local anesthetics is a simple, safe, and low-cost technique, which may improve perioperative analgesia due to inhibition of noxious impulse transmission at the wound site, resulting in anesthetic and analgesic-sparing effects [5][6][7][8]. In cats, reports of the effectiveness of infiltration of the surgical wound with local anesthetics are limited [5,7,8]. Recently, one study reported that intraoperative infiltration of bupivacaine in specific anatomical areas was an effective method for early postoperative pain control in cats undergoing ovariohysterectomy [8].…”

“…In cats, reports of the effectiveness of infiltration of the surgical wound with local anesthetics are limited [5,7,8]. Recently, one study reported that intraoperative infiltration of bupivacaine in specific anatomical areas was an effective method for early postoperative pain control in cats undergoing ovariohysterectomy [8]. Until now, no studies have reported the effects of ropivacaine as part of a multimodal analgesia protocol in cats.…”

2022 ISFM Consensus Guidelines on the Management of Acute Pain in Cats

“…These techniques should be incorporated into multimodal pain management. 132,[138][139][140][141][142][143]…”