Transcutaneous auricular vagus nerve stimulation (taVNS) accelerates postoperative recovery in patients undergoing perianal surgery under spinal anesthesia: a randomized, controlled, double-blind prospective study

INTERVENTION: Transcutaneous auricular vagus nerve stimulation(taVNS) group:Effective transcutaneous auricular vagus nerve electrical stimulation is performed in the left concha cavity and the auricular vessel area ;False stimulus group:Ineffective electrical stimulation is performed in the left tragus area; CONDITION: Perianal diseases PRIMARY OUTCOME: Postoperative pain score; SECONDARY OUTCOME: Consumption of analgesic drugs;Postoperative recovery quality score; INCLUSION CRITERIA: 1) 18 years old <= age <= 65 years old, regardless of gender; 2) ASA grade I‐II (physical condition is acceptable, tolerable surgery); 3) Planned elective perianal surgery under spinal anesthesia (such as hemorrhoids, anal fistula, perianal abscess, etc.); 4) Voluntarily participate and sign the informed consent form.