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

BACKGROUND: Ultrasound-guided quadratus lumborum block (QLB) and sacrococcygeal epidural anaesthesia (ScE) have been used for neutering cats, providing effective pain relief.

OBJECTIVES: To compare the effects of the QLB with those of ScE in cats undergoing ovariectomies.

METHODS: Feral cats undergoing ovariectomy were premedicated with dexmedetomidine (20 μg kg-1 ) and methadone (0.2 mg kg-1 ) intramuscularly. Anaesthesia was induced with 2-4 mg kg-1 of propofol intravenously and maintained with isoflurane in oxygen. The cats were randomly allocated to the groups QLB (bilateral QLB with 0.4 mL kg-1 of 0.25% bupivacaine) and ScE (0.3 mL kg-1 of 0.25% bupivacaine). Hemodynamic data and analgesia rescue were collected at four intraoperative periods. The pain scale and motor block were assessed in both groups during the postoperative period.

RESULTS: The ScE results in increased hypotension, prolonged extubation time, and higher postoperative motor block than the QLB ( p < 0.05). The QLB and ScE groups required a similar number of intraoperative rescues and presented the same postoperative pain scale classification.

CONCLUSIONS: The QLB with 0.25% bupivacaine is a potential alternative to ScE with 0.25% bupivacaine in perioperative pain management in elective cat ovariectomy. The QLB promoted less hypotension and postoperative motor block when compared with the ScE group.