Analgesic Efficacy of Bilateral Erector Spinae Plane Block in Pediatric Tethered Cord Syndrome Surgery

In the ESP Block group, with the patient in the prone position, the research anesthesia team will insert a block needle through the skin one level above the surgical level using a linear probe guided by USG. The needle will pass through the trapezius and erector spinae muscles, and upon reaching the transverse process (approximately 2-3 cm deep), a test dose of 0.5-1 mL of 0.9% NaCl will be applied between the erector spinae fascia and the vertebral transverse process to confirm needle placement. After confirmation of fascial opening, a local anesthetic volume of 2 mL per vertebral pressure will be calculated, not exceeding a maximum dose of 2 mg/kg of 0.5% bupivacaine. This total volume will be diluted by half with 0.9% NaCl solution to prepare a 0.25% bupivacaine concentration. The calculated local anesthetic solution will be applied to the erector spinae region for ESPB. The same procedures will be performed on the opposite side.

For the ESP Block group, under USG guidance with the patient in prone position, a linear probe will be placed in the parasagittal plane one level above the operative level, and after visualizing the transverse process with an in-plane approach, a 50 mm long block needle will be inserted through the skin. A test dose of 0.5-1 mL of 0.9% NaCl will be administered between the erector spinae fascia and the transverse process of the vertebra to confirm needle placement. After confirming that the fascia has opened, a local anesthetic volume of 2 mL per vertebral pressure will be calculated, not exceeding a maximum dose of 2 mg/kg of 0.5% bupivacaine. This total volume will be diluted halfway with 0.9% NaCl solution to prepare a 0.25% bupivacaine concentration. The calculated local anesthetic solution will be administered to the erector spinae area, and ESPB will be performed. The same procedures will be performed on the opposite side.