Dexmedetomidine for Improving Emergence Quality in Thyroid Surgery

Inclusion Criteria: * Age 18-65 years. * American Society of Anesthesiologists (ASA) physical status I-III. * Scheduled for elective thyroid surgery (thyroidectomy) under general anesthesia with endotracheal intubation. * Able to understand the study procedures and provide written informed consent. Exclusion Criteria: * Known hypersensitivity or contraindication to dexmedetomidine or study-related medications. * Clinically significant cardiac conduction abnormality or arrhythmia (e.g., second- or third-degree atrioventricular block without a pacemaker), severe bradyarrhythmia, or unstable cardiovascular disease. * Severe hepatic dysfunction or severe renal failure. * Pregnancy or breastfeeding. * Planned postoperative ICU admission or postoperative deterioration requiring ICU admission. * Major intraoperative complications (e.g., major bleeding requiring urgent hemostatic intervention, tracheal or esophageal injury, or recurrent laryngeal nerve injury identified intraoperatively). * Any condition that, in the investigator's judgment, would interfere with outcome assessment or increase risk (e.g., inability to reliably report pain scores or complete QoR-15).