Bupivacaine-Lidocaine vs Bupivacaine for Ultrasound-Guided Popliteal Sciatic Nerve Block

This prospective, randomized, double-blind clinical trial aims to compare the efficacy of two local anesthetic regimens for ultrasound-guided popliteal sciatic nerve block in adult patients undergoing elective distal lower extremity surgery. Eligible participants (ages 18-65, ASA physical status I-III, BMI 18-35 kg/m²) will be randomized into two equal groups of 30. Patients in Group BL will receive a combination of 10 mL 2% lidocaine and 10 mL 0.5% bupivacaine, while patients in Group B will receive 20 mL 0.5% bupivacaine alone, administered via ultrasound-guided popliteal sciatic nerve block prior to surgery. The primary outcome is the onset time of sensory and motor blockade. Secondary outcomes include block success rate, duration of sensory and motor block, postoperative opioid consumption, pain scores assessed by the Numeric Rating Scale (NRS) at 2, 4, 8, 12, and 24 hours postoperatively, Quality of Recovery-15 (QoR-15) score, and incidence of rebound pain. The study is conducted at Ataturk University Research Hospital, Department of Anesthesiology and Reanimation, Erzurum, Turkey.