Vet Anaesth Analg. 2026 Feb 28;53(3):101217. doi: 10.1016/j.vaa.2026.101217. Online ahead of print.
ABSTRACT
OBJECTIVE: To evaluate the isoflurane-sparing effect and the intra- and postoperative analgesic efficacy of an ultrasound-guided transversus abdominis plane (TAP) block in pigs undergoing elective laparoscopic ovariectomy.
STUDY DESIGN: Prospective, randomised, blinded clinical study ANIMALS: A total of 35 female pigs.
METHODS: Pigs were randomly allocated to TAP or control groups. Premedication consisted of azaperone 1 mg kg-1, xylazine 1.5 mg kg-1, butorphanol 0.2 mg kg-1, and ketamine 5 mg kg-1 intramuscularly. Anaesthesia was induced with ketamine ± thiopental intravenously and maintained with isoflurane. A three-injection-point per hemiabdomen ultrasound-guided TAP block was performed with 1% lidocaine, 0.1 mL kg-1 per point. No sham injection was performed in controls. Baseline heart rate (HR) and mean arterial pressure (MAP) were recorded before surgery at 1.0% end-tidal isoflurane (FE´Iso). Anaesthetic requirements were adjusted by a blinded investigator if HR and MAP deviated 20% from baseline. Ketamine 1 mg kg-1 was administered for ventilator asynchrony. Postoperative pain was assessed using the UNESP-Botucatu pig composite acute pain scale. Pigs scoring ≥ 6/18 were given oral paracetamol 30 mg kg-1. Statistical significance was set at p < 0.05.
RESULTS: After excluding nine pigs,12 were analysed in the TAP group and 14 in the control group. No statistically significant difference was found comparing overall isoflurane requirements (mean ± standard deviation FE´Iso area-under-the-curve: 7.12 ± 0.89 versus 7.19 ± 1.04 in TAP and control groups, respectively p = 0.775). Median postoperative pain scores (interquartile range) were 1 (1-4) in the TAP group and 1 (0-2) in controls. No significant differences were found in rescue analgesia requirements intra- (p = 0.759) or postoperatively (p = 0.867).
CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasound-guided TAP block is a feasible technique in pigs. With the methodology used, no isoflurane-sparing effect of the TAP block was detected.
PMID:41966612 | DOI:10.1016/j.vaa.2026.101217
