Effect of Tramadol on Postoperative Sore Throat After General Anesthesia

Inclusion Criteria: \- Female with American Society of Anesthesiologists (ASA) physical status I-II; Elective thyroidectomy(non-endoscopic) with endotracheal intubation; The patient signed the consent form. Exclusion Criteria: \- History of thyroid surgery A history of preoperative sore throat; Pregnancy; Retrosternal goiter; Thyroid tumor invading trachea need trachea reconstruction; Potentially difficult airway; Clinical diagnosis of chronic sore throat; Clinical diagnosis of psychosis; Tracheotomy after operation； Transfer to intensive care unit after operation； Contraindications to tramadol； Body mass index (BMI) \> 30kg/m\^2.