Study Summary

60 patients scheduled for single-level lumbar spine fixation were randomized to receive bilateral ultrasound-guided erector spinae plane block with 10 ml, 15 ml, or 20 ml of bupivacaine 0.25% per side. The primary outcome of interest was total postoperative morphine consumption within the first 24 hours. Secondary outcomes included pain scores, time to first rescue analgesia, intraoperative fentanyl requirements, ambulation time, patient satisfaction, and complications. Outcomes were assessed from the post-anesthesia care unit through 48 hours postoperatively. Overall, the results of the study revealed that 10 ml and 15 ml volumes were non-inferior to 20 ml in terms of opioid consumption, pain scores, and recovery parameters. These findings suggest that lower volumes of local anesthetic in erector spinae plane block provide effective analgesia while potentially reducing the risk of toxicity and side effects.