Does timing matter? Comparing pre- and postoperative erector spinae plane blocks in lumbar spine surgery

PURPOSE: Effective analgesia is crucial in lumbar spine surgery. The erector spinae plane (ESP) block has emerged as a reliable regional technique; however, the optimal timing of its administration-preoperatively or postoperatively-remains uncertain. This study aimed to compare total 24-hour opioid consumption between preoperative and postoperative ESP block in lumbar spine surgery patients. METHODS: A total of 46 patients aged 18-75 years, classified as ASA physical status I-III and scheduled for elective lumbar spinal surgery, were enrolled in this prospective, randomized, as a randomized, patient- and outcome-assessor-blinded trial. Patients were randomized into two groups: Group 1 received an ESP block before surgery, whereas Group 2 received the block after surgery but prior to awakening. The primary outcome was total opioid consumption. Secondary outcomes included Numerical Rating Scale (NRS) pain scores at 0, 1, 6, 12, 18, and 24 h, quality of recovery assessed with the The Quality of Recovery-40 (QoR-40) score at 24 h, requirement for additional postoperative analgesia, discharge timing, and the occurrence of adverse effects. RESULTS: Total opioid consumption was comparable between the two groups (p > 0.05). Pain scores at 24 h were slightly lower in Group 2 (p < 0.05), while other time points showed no significant differences. The "comfort" subdomain of QoR-40 was higher in Group 1 (p < 0.05), whereas global QoR-40 scores were similar. No differences were observed in rescue analgesia use, discharge time, or incidence of adverse effects. CONCLUSION: Preoperative and postoperative ESP blocks provide comparable analgesia and recovery profiles. Small differences-lower 24-hour pain scores favoring postoperative block and better comfort favoring preoperative block-appear statistically but not clinically significant. Postoperative ESP block may be a practical alternative when preoperative timing is not feasible. CLINICAL TRIAL REGISTRATION: (NCT06215053).