A comparison of analgesia between ropivacaine and liposomal bupivacaine for the erector spinae plane block in dogs undergoing hemiaminectomy surgery.

OBJECTIVE

To compare postoperative analgesic efficacy between ropivacaine and liposomal bupivacaine when used for an erector spinae plane (ESP) block as part of analgesic management for hemilaminectomy surgery caudal to the eleventh thoracic vertebrae.

STUDY

DESIGN

Randomized, blinded, single-center study.

ANIMALS: A total of 112 dogs.

METHODS

Following diagnosis of intervertebral disc extrusion caudal to the eleventh thoracic vertebra with magnetic resonance imaging, dogs were randomly assigned to either liposomal bupivacaine or ropivacaine (0.4 mL kg-1) for an ESP block. All dogs were anesthetized using the same anesthetic protocol. Rescue opioid analgesia was administered if physiological variables increased ≥ 10% from baseline following surgical stimulation. Pain was assessed using the short-form Glasgow Composite Measure Pain Scale (CMPS-SF) at initial presentation and 1, 4, 6, 12, and 24 hours postoperatively. Postoperative fentanyl (constant rate infusion) was administered to all dogs for 24 hours postoperatively. Postoperative ketamine was administered if the CMPS-SF score exceeded 6/24. Data were analyzed with a generalized linear mixed-effect model with a beta distribution and logit link function fitted, using the GLIMMIX procedure. Data are median (range).

RESULTS

Of the 112 dogs, 56 were administered liposomal bupivacaine and 56 ropivacaine. No significant difference in pain score was found between treatment groups [bupivacaine 3 (2-4), ropivacaine 3 (2-4); p = 0.540] across all time points. Pain scores at 1 [bupivacaine 3 (2-4), ropivacaine 3 (2-4); p < 0.0001)] and 4 [bupivacaine 3 (2-4), ropivacaine 3 (2-4); p = 0.004] hours postoperatively were significantly higher than at 24 hours [bupivacaine 2 (2-3), ropivacaine 2 (1-2)].

CONCLUSIONS AND CLINICAL RELEVANCE: These results indicate there is no significant difference in pain scores following use of ropivacaine or liposomal bupivacaine for an ESP block for hemilaminectomy surgery.