Comparison of ultrasound-guided lumbar plexus and sciatic nerve blocks with ropivacaine and sham blocks with saline on perianesthetic analgesia and recovery in dogs undergoing tibial plateau leveling osteotomy surgery

Abstract Objective To assess the effects of ultrasound-guided lumbar plexus and sciatic nerve blocks on perianesthetic analgesia and recovery quality in dogs undergoing tibial plateau leveling osteotomy (TPLO). Animals A group of 20 dogs. Study design Prospective, randomized, blinded, clinical study. Methods Dogs were assigned to group RA, administered lumbar plexus and sciatic nerve blocks with ropivacaine (1.5 mg kg −1 ), or group CON, administered sham blocks with saline. Dogs were administered hydromorphone (0.2 mg kg −1 ) and atropine (0.02 mg kg −1 ) subcutaneously before anesthesia was induced with intravenous propofol and maintained with isoflurane. Variables included duration to perform nerve blocks, intraoperative rescue analgesia, recovery score, postoperative pain scores (modified University of Melbourne, Colorado State University and VAS pain scales), postoperative rescue analgesia-sedation and complications observed. Two-tailed student’s t test, Mann–Whitney test, repeated measures anova , Friedman test and Fisher exact test were used for comparison. Significance was p Results Time to perform nerve blocks was median (range) 4.3 (2.6–6.1) minutes after aseptic skin preparation. Total fentanyl requirements were 14.2 ± 9 μg kg −1 for RA and 25.4 ± 10 μg kg −1 for CON ( p = 0.02). Incidence of hypotension (MAP p = 0.16). In CON, six out of eight dogs required more intensive treatment for hypotension than dogs in RA. Recovery scores were 1 (1–4) for RA and 2.5 (1–4) for CON ( p = 0.04). RA dogs were less likely to require fentanyl rescue analgesia during the postoperative period ( p = 0.04). Conclusion and clinical relevance As part of a multimodal analgesia regimen, ultrasound-guided lumbar plexus and sciatic nerve blocks provided greater analgesia and improved recovery quality in dogs during TPLO surgery.