This study investigates whether non-invasive transcutaneous auricular vagus nerve stimulation can alleviate postoperative pain in patients after cesarean section, and explores its possible mechanisms of action through an exploratory study.

Post-cesarean section pain, if improperly managed, may affect the prognosis of the mother and the health of the infant. There is an urgent need to explore safer, more effective, and more direct non-pharmacological, non-invasive adjunctive interventions to alleviate the pain associated with cesarean section. Non-invasive transcutaneous auricular vagus nerve stimulation is a green neuromodulatory measure that has shown significant improvement in various types of pain and holds great potential for relieving perioperative pain. This study aims to investigate whether non-invasive transcutaneous auricular vagus nerve stimulation can alleviate postoperative pain in patients after cesarean section and to explore the possible mechanisms by which it exerts its effects, through a prospective randomized controlled clinical trial.

Inclusion Criteria:

1. Patients are classified as American Society of Anesthesiologists (ASA) physical status I to III.
2. Scheduled for elective cesarean delivery under spinal anesthesia.
3. Patients are aged between 19 to 45 years old.
4. Patients have provided written informed consent.

Exclusion Criteria:

1. Local skin infection occurs in the auricular area during transcutaneous auricular vagus nerve stimulation.
2. Cases where spinal anesthesia fails and general anesthesia is required.
3. Patients with conditions such as recurrent alcohol abuse, fever, convulsions, or cardiopulmonary failure.
4. Patients who have used opioid medications at least 6 months prior to surgery.
5. Patients who are unable to understand the consent form and study questionnaire, including those with cognitive impairments.
6. Patients with a history of psychiatric illness.