Effect of transcutaneous auricular vagus nerve stimulation on postoperative quality of recovery in patients undergoing modified radical mastectomy for breast cancer: a randomized, double-blind, controlled trial

INTERVENTION: Experimental group:The experimental group of patients underwent transcutaneous vagus nerve electrical stimulation, with the stimulation mode involving electrode stimulation of the left auricular branch of the vagus nerve for a duration of 60 minutes. The stimulation frequency was set at 20Hz, pulse width at 200 microseconds, and intensity adjusted to the maximum tolerable level for each patient;Control group:The control group will have the stimulating electrodes placed on the corresponding areas,opening the instrument,after a brief intensity adjustment is performed,turn off the instrument and give 60min "pseudo‐stimulation"; CONDITION: Breast cancer PRIMARY OUTCOME: Recovery quality; SECONDARY OUTCOME: Pain score;Anxiety score;Depression score;Sleep quality;Shoulder Pain and Disability Index;Postoperative adverse events; INCLUSION CRITERIA: 1. Age >=18 years old, <65 years old; 2. Patients undergoing unilateral modified radical mastectomy; 3. Clinical diagnosis of stage ?‐II primary breast cancer; 4, ASAI, grade II