Transauricular Vagus Nerve Stimulation Frequencies for Postoperative Pain

Recruiting now · Not applicable · Has a placebo group

Conditions studied: Postoperative Pain, Postoperative Nausea and Vomiting (PONV), Opioid Consumption, Postoperative

In brief

The goal of this clinical trial is to learn whether different frequencies of transauricular vagus nerve stimulation (tVNS) can reduce postoperative pain and opioid consumption in adults undergoing abdominal or urologic surgery. It will also evaluate the effects of tVNS on recovery quality, autonomic function, and treatment safety. The main questions it aims to answer are: Does transauricular vagus nerve stimulation reduce postoperative opioid consumption during the first 24 hours after surgery? Do different stimulation frequencies (high-frequency and low-frequency tVNS) produce different effects on postoperative pain and autonomic responses? Is transauricular vagus nerve stimulation safe and well tolerated in surgical patients? Researchers will compare high-frequency tVNS, low-frequency tVNS, and sham stimulation (inactive stimulation) to determine their effects on postoperative pain and opioid requirements. Participants will: Be randomly assigned to receive high-frequency tVNS, low-frequency tVNS, or sham stimulation. Receive two 30-minute stimulation sessions, one before anesthesia and one after surgery in the post-anesthesia care unit. Undergo assessments of postoperative pain, opioid consumption, need for rescue analgesics, postoperative nausea and vomiting, heart rate changes, and quality of recovery. Be monitored for adverse events related to the intervention during the study period. A total of 174 participants will be enrolled in this single-center, randomized, double-blind, sham-controlled clinical trial.

Key facts

Study ID

NCT07633444

Run by

Federal University of Bahia

People needed

174

Starts

2026-06-01

Expected to finish

2026-12-04

Last updated by the study team

2026-06-10

Who can join

Age: 18 and older, up to 59. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• 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.

You may not qualify if…

• 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 is running

• Hospital Universitário Professor Edgard Santos, Federal University of Bahia (HUPES-UFBA) — Salvador, Estado de Bahia, Brazil (enrolling)

Full record on ClinicalTrials.gov

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