Postoperative Pain Monitoring With ANI in Lumbar Spine Surgery

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.