Effects of taVNS Combined With Dexmedetomidine on POVN

Exclusion Criteria

• •Patients with ASA anesthesia classification ≥ III;
• •Poorly controlled hypertension, atrioventricular block ≥ second degree, obesity (BMI \> 30 kg/m²);
• •Pregnant or breastfeeding;
• •Known allergy to drugs used in the study protocol, history of traumatic brain injury, history of gastrointestinal surgery;
• •Liver or kidney dysfunction (liver enzymes or creatinine ≥ 1.5 times the normal value), alcoholism or drug abuse, mental illness, use of antiemetics, opioids, psychoactive drugs, or corticosteroids within 24 hours before surgery;
• •Patients with implanted stimulators (such as pacemakers, implantable vagus nerve stimulators, deep brain stimulators, spinal cord stimulators, etc.), cochlear implants, or metal implants (except in dental cases);
• •Skin lesions or dermatological diseases at the site of electrical stimulation;
• •Preoperative heart rate \< 50 bpm or the presence of sinoatrial node disease or second-degree or higher atrioventricular block;
• •Patients unable to cooperate with assessments;
• •Patients participating in other clinical trials.