Sessions

Locoregional anaesthesia is internationally recommended as part of a multimodal analgesia protocol for canine stifle surgery and has been increasingly incorporated into clinical practice. This retrospective study examined whether peripheral nerve blocks of the hindlimb were associated with lower intraoperative anaesthetic and analgesic requirements and greater cardiovascular stability in dogs undergoing tibial plateau levelling osteotomy (TPLO) or surgical stabilisation of patellar luxation at the Department and Clinic of Surgery and Ophthalmology of the University of Veterinary Medicine Budapest.

Anaesthetic records of 109 procedures in 99 dogs, performed between February 2025 and June 2026, were reviewed. The cases were grouped according to whether patients received a sciatic and femoral block with a local anaesthetic (LA group, n=89) or not (No LA group, n=20). The LA group was further divided according to whether a ketamine–fentanyl infusion was also administered (LA + drip, n=73, LA only, n=13).

Mean end-tidal isoflurane concentration (EtISO) did not differ between the NoLA, LA only and LA+drip groups (median 1.32–1.37%, p=0.62). Total intraoperative fentanyl administration (n=84) did not differ between LA + drip and No LA groups (median 6.0 vs 6.5 µg/kg/h, p=0.28). Dogs in the LA only group received fentanyl as rescue boluses (median of 1.2 µg/kg/h) only, without a detectable increase in rescue fentanyl dose compared with the other groups (p = 0.58). Mean arterial pressure (MAP, median 76.3–79.9 mmHg), the incidence of hypotension (40–54%) and the proportion of dogs receiving rescue analgesia (53–62%) was similar between the No LA, LA only and LA + drip groups. Patellar stabilisation was performed almost exclusively in dogs under 10 kg (31 of 33), which had higher EtISO (1.40 vs 1.33%, p=0.001), lower MAP and more hypotension than TPLO patients.

Locoregional anaesthesia was not associated with detectable differences in isoflurane and rescue fentanyl requirement. The systemic analgesia protocol was applied largely independent of whether a block had been performed. The high rescue rate likely reflects the short interval between block and incision and incomplete coverage of the stifle joint by the femoral and sciatic block. The markedly lower fentanyl use in LA only dogs, without a worse anaesthetic course, suggests an opioid-sparing potential of the block that should be tested prospectively.