In recent years, the application of intraoperative recurrent laryngeal nerve monitoring in thyroid surgery has greatly reduced the complications of recurrent laryngeal nerve injury. The use of intraoperative neurological monitoring requires the reduction of the dose of neuromuscular blockade, which often leads to muscle tremors during the application of electrical energy, which affects the fine separation around the muscles. This study explored the effect of local application of lidocaine on reducing muscle tremor during surgery and its optimal dose.

According to the random number method, eligible patients were randomly divided into 2 groups. Group A was the conventional surgery group, and Group B was the lidocaine group. The operative time for the separation of the sternocleidomastoid muscle from the two groups of patients was analyzed, as well as the length of time for the search for the accessory nerve and the effect of intraoperative nerve monitoring on the EMG signal.

Inclusion Criteria:

• Thyroid papillary carcinoma
• Lateral cervical lymph node metastasis
• The diameter of the metastatic lymph nodes is less than 3cm
• Without internal jugular vein invasion

Exclusion Criteria:

• Lidocaine allergy sufferers