This study aims to compare two different pain management methods in patients undergoing elective lumbar spine surgery. Patients are randomly assigned to receive either an ultrasound-guided erector spinae plane block (ESPB) or intravenous multimodal analgesia.
Postoperative pain will be assessed using both clinical pain scores and the Analgesia Nociception Index (ANI), a non-invasive monitoring system that evaluates pain-related responses based on heart rate variability. The goal of this study is to determine which method provides better postoperative pain control.