Comparison of short-term postoperative analgesia by epidural, femoral nerve block, or combination femoral and sciatic nerve block in dogs undergoing tibial plateau leveling osteotomy

OBJECTIVE: To compare early postoperative analgesia in dogs undergoing unilateral tibial plateau leveling osteotomy (TPLO) that received bupivacaine via preoperative femoral nerve block (FNB), combination femoral-sciatic nerve block (F+SNB), or lumbosacral epidural (EPI).

STUDY DESIGN: Randomized, blinded, prospective clinical trial.

ANIMALS: Forty-five client-owned dogs undergoing unilateral TPLO.

METHODS: Dogs undergoing unilateral TPLO were enrolled and randomly allocated to 1 of 3 treatments: FNB, F+SNB, or EPI. Assessments were completed by an observer blinded to treatment at 0, 1, 2, 4, 6, and 8 hours after extubation using the Glasgow Composite Pain Score-Short Form (GCPS-SF). Dogs with a total score ≥6 or ≥3 in any category were given a rescue analgesic. Outcome measures analyzed for differences across treatments were the GCPS-SF at each time point, time to first rescue analgesic, and total number of rescue analgesic doses per dog.

RESULTS: The GCPS-SF score at extubation was significantly higher for FNB (median 3) compared to F+SNB (median 2). A significantly higher proportion of dogs receiving FNB (4/14) than F+SNB (0/17) required rescue analgesic at extubation. There was no significant difference in the proportion of dogs requiring rescue at extubation between FNB and EPI (2/14) or between F+SNB and EPI. There was no significant difference in the median time to first rescue between FNB (0 hours) and F+SNB (2 hours) or between F+SNB and EPI (1.5 hours).

CONCLUSION: In dogs undergoing unilateral TPLO, bupivacaine administered via FNB, alone or in combination with sciatic nerve block, can provide short-term postoperative analgesia not different to that with administration via lumbosacral epidural.