Thyroid surgery is a common type of surgery in thyroid and breast surgery, mainly used to treat benign and malignant thyroid diseases. Despite the continuous progress in surgical techniques and anesthesia management, postoperative sore throat (POST) is still one of the most common adverse reactions in the perioperative period. It is reported that the incidence of POST in patients undergoing general anesthesia is about 15%-62%, while the incidence in the thyroid surgery population can be as high as 68%-80%. POST not only increases the patient's postoperative discomfort, but also may affect swallowing and language functions, prolong hospitalization time, reduce the quality of postoperative recovery, and increase medical costs. Therefore, effectively reducing the incidence and severity of POST is of great significance for improving the prognosis of patients after thyroid surgery.

The mechanism of postoperative sore throat after thyroid surgery is relatively complex, mainly involving two aspects. First, endotracheal intubation is a necessary operation for general anesthesia. The mechanical stimulation, improper airbag pressure, unreasonable catheter model selection, and rough intubation operation can all lead to pharyngeal mucosal damage, congestion, and edema, thereby causing acute POST. Secondly, thyroid surgery itself may also cause pharyngitis, such as traction and compression of the trachea, recurrent laryngeal nerve and pharyngeal soft tissue during surgery, excessive backward tilt of the head and neck during surgery, and local stimulation caused by recurrent laryngeal nerve function monitoring. The above factors work together to cause the incidence and severity of POST in thyroid surgery patients to be significantly higher than other types of surgery.

At present, measures to reduce POST mainly include reducing the inner diameter of the tracheal tube, controlling the airbag pressure, lubricating the tracheal tube, and using glucocorticoids or local anesthetics, but the effect is limited, and some interventions have the risk of drug side effects. In recent years, transcutaneous electrical acupoint stimulation (TEAS) as a non-invasive and non-traumatic intervention has shown good application prospects in relieving perioperative stress, reducing nausea and vomiting, and promoting gastrointestinal function recovery. Studies have shown that TEAS can effectively relieve a variety of postoperative discomfort symptoms, including laryngeal discomfort and pharyngitis, by regulating the autonomic nervous system, activating the endogenous analgesic system, and reducing the levels of inflammatory factors (such as IL-6 and TNF-α).

Among the many optional acupoints, Lieque (LU7) and Zhaohai (KI6) have been used in the treatment of throat diseases in ancient literature due to their status as "eight meridian intersection points". Modern studies have also confirmed that this acupoint combination has a clear effect on improving throat foreign body sensation, pharyngeal pain and hoarseness. However, there is currently no prospective randomized controlled study focusing on Lieque and Zhaohai acupoints combined with TEAS intervention for people with throat pain after thyroid surgery. Therefore, this study intends to use TEAS intervention on bilateral Lieque and Zhaohai acupoints to comprehensively observe the effect on the incidence and severity of throat pain after thyroid surgery, and evaluate its effect on postoperative nausea and vomiting, anxiety scores and hemodynamic indicators, aiming to provide new non-drug intervention strategies and evidence-based basis for the management of accelerated recovery after thyroid surgery (ERAS).

The goal of this clinical trial is to evaluate whether transcutaneous electrical acupoint stimulation (TEAS) can reduce postoperative sore throat (POST) and improve recovery quality in adult patients undergoing thyroid surgery under general anesthesia.

The main questions it aims to answer are:

Can TEAS at bilateral LU7 (Lieque) and KI6 (Zhaohai) acupoints reduce the incidence and severity of POST within 48 hours after thyroid surgery? Does TEAS influence postoperative nausea and vomiting, anxiety scores, and perioperative hemodynamic stability? Researchers will compare a TEAS group receiving active electrical stimulation at LU7 and KI6 with a control group receiving sham stimulation without current to see if TEAS results in improved postoperative comfort and faster recovery.

Participants will:

Be randomly assigned to TEAS or control group Undergo TEAS or sham stimulation for 30 minutes before induction of anesthesia Receive standard general anesthesia and thyroid surgery Be followed up for 48 hours postoperatively for sore throat assessment, discomfort scores, and related indicators

Inclusion Criteria:

• Age ≥ 18 years
• Undergoing thyroid surgery under general anesthesia, including both open and endoscopic approaches
• Provision of written informed consent by the patient or a legally authorized representative

Exclusion Criteria:

• Failed tracheal intubation or requirement for emergency tracheotomy during surgery
• Requirement for reoperation due to postoperative complications such as bleeding or nerve injury
• Presence of severe cardiopulmonary disease (ASA physical status ≥ IV) or long-term use of corticosteroids
• Incomplete clinical data or inability to complete follow-up