The Effect of Perioperative Intravenous Lidocaine Infusion on Post-amputation Pain in Amputee Patients

This study aimes to evaluate whether perioperative intravenous lidocaine infusion effectively relieves postoperative pain, enhances recovery, and reduces chronic stump and phantom limb pain after amputation, thereby informing future multicenter trials and clinical guideline development.

Inclusion Criteria: * 1.Age 18-80 years; 2.Patients scheduled for elective or emergency primary above or below knee amputation (AKA or BKA) under general anesthesia; 3.American Society of Anesthesiologists (ASA) physical status I-III. The exclusion criteria. Exclusion Criteria: * 1\. Body weight \< 40 kg or \> 100 kg； 2. Cardiac conduction defects (second- or third-degree atrioventricular block) or cardiac insufficiency (left ventricular ejection fraction \[LVEF\] \< 50%)； 3. Severe hepatic impairment (alanine aminotransferase \[ALT\], aspartate aminotransferase \[AST\], or bilirubin levels \> 2.5 times the upper limit of normal) 4. Renal insufficiency (creatinine clearance \[CrCl\] \< 60 mL/min)； 5. Known allergy to the study drug； 6. Chronic opioid abuse； 7. Patients unable to communicate verbally.