Analgesic efficacy of an ultrasound-guided transversus abdominis plane block with bupivacaine in cats: a randomised, prospective, masked, placebo-controlled clinical trial

Abstract

Objectives This randomised, prospective, masked clinical trial evaluated the postoperative analgesic efficacy of an ultrasound-guided transversus abdominis plane block (TAPB) with bupivacaine in cats undergoing ovariohysterectomy. Methods Thirty-two healthy adult female cats undergoing elective ovariohysterectomy were randomised to undergo TAPB with bupivacaine (treatment group [TG], n = 16) vs placebo (control group [CG], n = 16) in addition to preoperative analgesia with buprenorphine (0.02 mg/kg IM). All patients received a general anaesthetic and, before surgical incision, a bilateral two-point (subcostal and lateral–longitudinal) TAPB was performed using 1 ml/kg bupivacaine 0.25% (0.25 ml/kg/point) or saline. Each cat was assessed by a blinded investigator before premedication (0 h) and at 1, 2, 3, 4, 8, 10 and 24 h postoperatively using the UNESP-Botucatu Feline Pain Scale – short form. Buprenorphine (0.02 mg/kg IV) and meloxicam (0.2 mg/kg SC) were administered when pain scores were ⩾4/12. Ten hours postoperatively, meloxicam was administered to cats that did not receive rescue analgesia. Statistical analysis included Student’s t-tests, Wilcoxon tests and χ2 tests, and a linear mixed model with Bonferroni corrections ( P <0.05). Results Of the 32 cats enrolled, three in the CG were excluded from the analysis. The prevalence of rescue analgesia was significantly higher in the CG (n = 13/13) than in the TG (n = 3/16; P <0.001). Only one cat in the CG required rescue analgesia twice. Pain scores were significantly higher in the CG compared with the TG at 2, 4 and 8 h postoperatively. Mean ± SD pain scores were significantly higher in the CG, but not in the TG, at 2 (2.1 ± 1.9), 3 (1.9 ± 1.6), 4 (3.0 ± 1.4) and 8 h postoperatively (4.7 ± 0.6) than at 0 h (0.1 ± 0.3). Conclusions and relevance A bilateral ultrasound-guided two-point TAPB with bupivacaine in combination with systemic buprenorphine provided superior postoperative analgesia than buprenorphine alone in cats undergoing ovariohysterectomy.

Modified Ultrasound-Guided Dorsal Quadratus Lumborum Block in Cat Cadavers

“…Using a QL block, all these side effects could be avoided. Comparing different fascial blocks, the TAP block has been shown to provide abdominal analgesia in cats undergoing elective ovariohysterectomy [8]. In contrast, RS block seemed to reduce isoflurane requirements during ovariectomy but not the scores of postoperative pain compared to the control group [9].…”

“…In veterinary medicine, the need to provide effective analgesia to the abdomen has led to the implementation of different locoregional anesthesia techniques. Among them, the transversus abdominis plane (TAP) block [8] and the rectus sheath (RS) block [9] have been reported to desensitize the abdominal wall. As the gold standard, epidural anesthesia induces both somatic and visceral analgesia of the abdomen but impairs motor activity in the pelvic limbs [10].…”

Comparison between Bilateral Ultrasound-Guided Quadratus Lumborum Block and Sacrococcygeal Epidural in Cats Undergoing Ovariectomy

“…The ovariectomy is commonly used in veterinary medicine as a model of acute intraoperative abdominal pain [ 1 , 2 , 3 ]. Maintaining the stability of the autonomic nervous system is crucial during general anaesthesia, underscoring the need for adequate intraoperative analgesia [ 4 , 5 ].…”

“…Maintaining the stability of the autonomic nervous system is crucial during general anaesthesia, underscoring the need for adequate intraoperative analgesia [ 4 , 5 ]. Regional anaesthesia is widely accepted as an optimal method to prevent perioperative pain [ 3 , 6 ], as it effectively blocks nociceptive transmission [ 3 , 7 ].…”

“…Different regional anaesthesia techniques have been used for neutering cats, providing effective pain relief [ 3 , 7 , 8 , 9 ]. One such technique is ultrasound-guided quadratus lumborum block (QLB), which has been described in cadavers [ 10 ] and found to be effective in cat ovariectomies [ 9 ].…”