Effects of taVNS on Postoperative Pain in Complex Spinal Surgery

Effect of Transcutaneous Auricular Vagus Nerve Stimulation on Postoperative Pain in Patients Undergoing Complex Spinal Surgery: a Randomized Controlled Trial

Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive, novel neuromodulation technique. Previous studies have demonstrated its safety and efficacy in chronic pain, mental disorders, and other diseases, but evidence regarding its use in acute postoperative pain remains limited. This project aims to explore the efficacy and safety of taVNS in managing acute pain after complex spinal surgery. This is a single-center, double-blind, randomized controlled clinical trial, planning to recruit 98 patients scheduled to undergo complex spinal surgery at the Second Affiliated Hospital of Zhejiang University School of Medicine. Participants will be randomly assigned to either the experimental group (taVNS stimulation) or the control group (sham stimulation). The experimental group will receive five stimulation sessions, each lasting one hour, from one day before surgery to three days after surgery. The primary outcome was opioid consumption within 72 hours postoperatively. Secondary outcomes included the maximum, minimum, and mean NRS on postoperative days 1, 2, and 3; NRS before and after each taVNS stimulation; time to first PCIA compression and number of PCA sessions within 3 days postoperatively; Hospital Anxiety and Depression Scale (HADS), Pittsburgh Sleep Quality Index (PSQI), and Quality of Recovery Scale (QoR15) on postoperative day 3; time to first flatus, and first bowel movement; and the incidence of chronic pain, HADS, PSQI, and QoR15 at 3 months postoperatively.

Inclusion Criteria:

1. Patients undergoing elective general anesthesia for complex spinal surgeries
2. Age ≥ 18 years
3. ASA classification I-III

Exclusion Criteria:

1. Ulceration or infection of the auricle skin
2. Bradycardia (heart rate of < 60 beats/min） or third-degree atrioventricular block
3. Implanted cardiac pacemaker or other electronic devices
4. Mental disorders or long-term use of psychotropic medications
5. Severe hepatic and renal insufficiency
6. Unable to understand the content of the scale assessment or unable to cooperate with the scale assessment
7. Pregnant or lactating women
8. Expected reoperation during hospitalization
9. Expected to be transferred to the ICU after surgery
10. Participation in other concurrent clinical trials