Transauricular Vagus Nerve Stimulation at Different Frequencies for Postoperative Pain
Official title: Effects of Different Frequencies of Transauricular Vagus Nerve Stimulation on Postoperative Pain: A Randomized, Double-Blind, Sham-Controlled Trial With Preoperative and Postoperative Sessions
Run by Federal University of Bahia · NCT07633444 · Data updated 2026-11-12
Researchers will test whether different tVNS frequencies can lessen pain and reduce opioid use after abdominal or urologic surgery.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 18 Years to 59 Years |
| Sex | All |
| Enrollment | 174 (estimated) |
| Sponsor | Federal University of Bahia Academic / other |
| Locations | 1 site (Salvador, Estado de Bahia) |
| Status | Recruiting |
| Started | June 1, 2026 |
| Main results expected | November 30, 2026 |
| Study ends | December 4, 2026 |
| Registry record updated | June 10, 2026 |
| Trial ID | NCT07633444 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Adults aged 18 to 59 undergoing elective abdominal or urologic surgery with ASA I–III enrolled at participating sites.
✕Probably not a fit
Patients with certain neurological or psychiatric histories, skin issues at the stimulation site, chronic opioid use, implanted electronic devices, or other exclusion criteria may not benefit.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This randomized study compares high-frequency tVNS, low-frequency tVNS, and sham stimulation in adults undergoing elective abdominal or urologic surgery. The goal is to see if tVNS can lower postoperative pain scores and opioid consumption, and to assess effects on recovery quality and autonomic function while monitoring safety and tolerability. Non-invasive stimulation targets the auricular branch of the vagus nerve to potentially enhance pain modulation and inflammatory regulation. Outcomes include postoperative opioid use in the first 24 hours, pain intensity, autonomic responses, and adverse events. The trial aims to identify optimal stimulation parameters for perioperative analgesia.
Why it matters
Potential benefit: If successful, tVNS could provide a non-pharmacological option to reduce opioid needs and improve recovery after surgery.
How similar studies have gone: Previous studies in acute and chronic pain have shown promising but variable results for tVNS, with ongoing investigation needed for perioperative analgesia.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Adults aged 18 to 59 years. * Undergoing elective abdominal or urologic surgery. * American Society of Anesthesiologists (ASA) physical status I-III. * Able and willing to provide written informed consent. Exclusion Criteria: * History of neurological disorders. * History of psychiatric disorders. * Inability to understand study procedures. * Pregnancy. * Cognitive impairment. * Communication difficulties that interfere with study assessments. * Auricular dermatitis or skin lesions at the stimulation site. * Pre-existing cardiac arrhythmia. * Chronic opioid use. * Implanted electronic medical devices, including pacemakers.
Where it's running
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Hospital Universitário Professor Edgard Santos, Federal University of Bahia (HUPES-UFBA)
Salvador, Estado de Bahia, Brazil Recruiting
Study contacts
- Principal investigator: Rodrigo M Vieira, MD — Botucatu Medical School, São Paulo State University (UNESP)
- Study coordinator: Rodrigo L Alves, MD, PhD
- Email: rlalves@ufba.br
- Phone: 71 99961-9818
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.