Retrospective comparison of intraoperative analgesic requirements in dogs receiving erector spinae plane block, epaxial infiltration or no block before undergoing thoracolumbar hemilaminectomy

BACKGROUND: This retrospective study compared intraoperative analgesic requirements in dogs undergoing thoracolumbar hemilaminectomy receiving no local anaesthesia (NB), peri-incisional epaxial muscle infiltration (EB) or ultrasound-guided erector spinae plane block (ESPB) with bupivacaine. METHODS: Medical records were reviewed, and cases were grouped into NB, EB and ultrasound-guided ESPB. Intraoperative analgesia interventions were recorded and analysed. RESULTS: A total of 377 cases were included. Additional analgesia was required in 63.2% of the NB group, 42.5% in the EB group and 23.4% in the ESPB group at the first incision. Significant differences were found between NB and EB (p < 0.005), between NB and ESPB (p < 0.001), and between EB and ESPB (p = 0.012). The median number of interventions was 2 (range 0‒8) in NB, 1 (range 0‒8) in EB and 1 (range 0‒5) in ESPB. ESPB required significantly fewer interventions than NB and EB (p < 0.001). LIMITATIONS: Due to the retrospective nature of the study, pain scores in recovery were not consistently available. CONCLUSIONS: Bupivacaine ESPB significantly reduced the use of intraoperative analgesics compared to EB and no local block. Compared with no block, EB reduced analgesic requirements, although not significantly.