BackgroundPosterior spinal fusion (PSF) for the correction of idiopathic scoliosis is associated with severe postoperative pain. Erector spinae plane block (ESPB) has been proposed to provide analgesia and reduce opioid consumption. We aimed to investigate the effect of bilateral ultrasound-guided single-shot ESPB on postoperative analgesia in pediatric patients undergoing PSF.MethodsThis double-blinded, randomized controlled trial will enroll 74 AIS patients undergoing elective PSF. Participants will be assigned to the ESPB group or control group at a 1:1 ratio. Patients in the ESPB group will receive ultrasound-guided bilateral ESPB preoperatively, and patients in the control group received sham ESPB using normal saline. The primary joint endpoints are the area under the curve (AUC) of numerical rating scale (NRS) score and opioid consumption in postoperative 24 h. The secondary endpoints are numerical rating scale (NRS) score and opioid consumption at postoperative 0.5, 3, 6, 9, 12, 24, 36, and 48 h, rescue analgesia, recovery outcomes, and adverse events.DiscussionAt present, studies investigating the effect of ESPB on pediatric patients are still needed. This study focuses on the effect of ESPB on pediatric patients undergoing PSF on postoperative pain control and intends to provide a new strategy of multimodal analgesia management for major spine surgery.Trial registrationChinese Clinical Trial Registry ChiCTR2300074505. Registered on August 8, 2023.