Analgesic Effects of Ultrasound-Guided Erector Spinae Plane Block v.s Patient Controlled Analgesia in Correction Surgery for Idiopathic Scoliosis: A Randomized Controlled Trial

Scoliosis correction surgery involves large surgical wounds spanning multiple vertebrae, requiring sufficient analgesia to manage intense intraoperative stimulation and severe postoperative pain. Effective pain control in this context often necessitates potent opioids, such as morphine or equivalent drugs. Current perioperative analgesia strategies include intraoperative use of long-acting opioids (e.g., sufentanil, fentanyl) and patient-controlled analgesia (PCA) pumps for postoperative pain management, primarily involving opioids like sufentanil or morphine. However, opioids are associated with adverse effects such as nausea, vomiting, bowel obstruction, pruritus, dizziness, respiratory depression, opioid tolerance, and hyperalgesia, which can lead to suboptimal pain control and negatively impact patients' quality of life and postoperative recovery. There is a critical need for effective analgesic methods in scoliosis correction surgery that minimize opioid-related adverse effects, enhance the patient experience, and promote accelerated recovery.

The Erector Spinae Plane Block (ESPB) was first reported by Forero et al. in 2016 as an effective analgesic technique for rib-related neuropathic pain. Its mechanism involves the injection of local anesthetics into the fascial plane between the erector spinae muscle and the transverse process, allowing for the diffusion of the anesthetic to adjacent areas. ESPB exerts its primary analgesic effect through the posterior branches of spinal nerves and can further diffuse anteriorly to paravertebral and epidural spaces, and laterally across the costotransverse foramina, affecting nerve roots and visceral structures. This mechanism provides comprehensive analgesia. ESPB has since been widely applied in perioperative pain management for thoracic surgery, shoulder arthroscopy, breast surgery, abdominal surgery, cesarean sections, and urological procedures, as well as for acute and chronic pain conditions such as rib fractures, postherpetic neuralgia, burns, and cancer pain.

Studies have demonstrated that ESPB effectively reduces postoperative pain scores, decreases opioid consumption, delays the need for rescue analgesics, reduces the number of patients requiring rescue medication, and lowers the incidence of nausea and vomiting in spinal surgeries. Although there are limited case reports and clinical experience summarizing its perioperative analgesic effect in scoliosis correction surgery, preliminary findings suggest it is effective.

Based on the analgesic mechanism of ESPB and prior studies, we hypothesize that ESPB provides superior postoperative pain control compared to PCA, significantly reducing postoperative pain scores, perioperative opioid consumption, and associated adverse effects.