The Efficacy of Erector Spinae Plane Block Compared With Intrathecal Morphine in Postoperative Analgesia in Patients Undergoing Lumbar Spine Surgery: A Double-blind Prospective Comparative Study

Background: Severe postoperative pain is experienced by most patients who undergo spine surgery. Erector spinae plane block (ESPB) is a successful method for postoperative analgesia and has only minor complications. Intrathecal morphine (ITM) demonstrates high efficacy for analgesia up to 24 hours postsurgery. ESPBs and ITM for postoperative analgesia in lumbar spine surgeries have never been compared in prior studies. Objectives: This study aimed to compare the efficacy of ESPB and ITM in postoperative analgesia after lumbar spine surgeries. Study Design: A double-blind prospective comparative study. Setting: This study was performed at Al Fayoum University Hospital after being confirmed by the local institutional ethical committee (#80) with approval number M520 and retrospectively registered at clinicaltrials.gov number (NCT05123092). Methods: A prospective randomized double-blinded interventional trial was conducted with 82 patients, 41 in each group. In the ESPB group, a 0.25% bupivacaine injection was used to conduct a bilateral ultrasound-guided ESPB. In the ITM group, an injection of 0.3 mg morphine intrathecally was done. The Visual Analog Scale (VAS) was recorded as the primary outcome. The time to the first analgesic request, intra- and postoperative opioid consumption, hemodynamics, sedation score, and complications were also recorded as secondary outcomes. Results: Postoperative VAS scores were significantly lower in the intrathecal group throughout the postoperative period at all recorded study time points until 48 hours (P < 0.001). Time to the first rescue analgesia and doses of postoperative analgesic required were significant, with a P value of 0.000. Significant differences were found in postoperative oxygen saturation up to 24 hours (P < 0.001) and the sedation score up to 6 hours (P < 0.01). A higher incidence of complications was recorded in the ITM group (P = 0.000). Limitations: We did not measure patient preoperative VAS scores to ensure that the 2 groups were matched in pain severity. Also, we did not compare patient satisfaction. Another limitation was the inability to determine the degree of pain relief of ESPB since there was no control group in our study. Conclusion: We concluded that ITM 0.3 mg provides more potent analgesia up to 48 hours postoperatively than an ESPB, based upon VAS score, analgesic durations, and postoperative analgesic requirements.