Effect of opioid-free anesthesia on quality of recovery after thyroidectomy—— a randomized controlled trial

INTERVENTION: opioid‐free anaesthesia group:Patients in the opioid‐free group will receive bilateral superficial cervical plexus block+dexmedetomidine+esketamine+propofol anesthesia. ;opioid anesthesia group:The patients in the opioid anesthesia group will receive propofol combined with sufentanil and remifentanil anesthesia.; CONDITION: Thyroidectomy PRIMARY OUTCOME: The quality of recovery‐15 score at 24 hours after surgery; SECONDARY OUTCOME: consumption of postoperative analgesics;Blood pressure, heart rate and oxygen saturation during operation;consumption of vasoactive agents;Pain scores at rest and movement;Sleep quality score at surgical night;Postoperative nausea and vomiting score;time first time to first ambulation after surgerydrinking and eating, and days in hospita;The quality of recovery score at 1month after sugery;duration of anesthesia and surgery;sedation scores at 10, 20, and 30 minutes;Measurement of salivary cortisol, C‐reactive protein, and melatonin;time to first taking food and water;time of postoperative hospitalization; INCLUSION CRITERIA: Gender unlimited, patients undergoing elective thyroidectomy Age is 18‐65 years old; ASA I‐II level. Volunteer to participate in the study and sign an informed consent form.