Effects of Different Frequencies of Transauricular Vagus Nerve Stimulation on Postoperative Pain: A Randomized, Double-Blind, Sham-Controlled Trial With Preoperative and Postoperative Sessions
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 174
- 试验地点
- 1
研究概览
简要总结
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.
详细描述
Postoperative pain remains a major challenge in perioperative care and is associated with delayed recovery, increased healthcare utilization, and greater opioid consumption. Despite advances in multimodal analgesia, opioid medications continue to play a central role in postoperative pain management and may be associated with adverse effects such as nausea, vomiting, respiratory depression, and prolonged recovery. Therefore, the development of effective non-pharmacological adjunctive strategies is of considerable clinical interest.
Transauricular vagus nerve stimulation (tVNS) is a non-invasive neuromodulation technique that stimulates the auricular branch of the vagus nerve through the external ear. Experimental and clinical studies suggest that vagal stimulation may modulate pain perception through activation of central autonomic pathways, enhancement of descending inhibitory pain mechanisms, and regulation of inflammatory responses. Previous clinical trials have demonstrated promising effects of tVNS on acute and chronic pain conditions, including reductions in postoperative pain scores.
However, the optimal stimulation parameters for perioperative analgesia remain uncertain. In particular, the influence of stimulation frequency on clinical outcomes and autonomic responses has not been adequately investigated. Different stimulation frequencies may activate distinct neural pathways and produce different effects on pain modulation and autonomic regulation.
This study is designed to evaluate the effects of different frequencies of transauricular vagus nerve stimulation applied before and after surgery in adult patients undergoing elective surgical procedures. In addition to assessing postoperative opioid requirements, the study will explore the relationship between autonomic responses and postoperative recovery. The findings may contribute to the optimization of non-pharmacological analgesic strategies and support the incorporation of transauricular vagus nerve stimulation into multimodal perioperative pain management protocols.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
盲法说明
Participants, outcome assessors, and data analysts will remain blinded to treatment allocation throughout the study. The researcher responsible for administering the stimulation will not be blinded because intervention assignment is required for device setup and delivery.
入排标准
- 年龄范围
- 18 Years 至 59 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •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.
排除标准
- •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.
研究组 & 干预措施
Sham tVNS
Participants will receive sham transauricular vagus nerve stimulation. The device will be positioned and activated to mimic active treatment, but stimulation will be discontinued shortly after initiation. Participants will undergo two 30-minute sessions, one before anesthesia and one after surgery, while maintaining blinding to treatment allocation.
干预措施: Sham Transauricular Vagus Nerve Stimulation (sham tVNS) (Device)
High-Frequency tVNS
Participants will receive active transauricular vagus nerve stimulation (tVNS) at a frequency of 60-120 Hz. Stimulation will be applied bilaterally to the auricular branch of the vagus nerve for 30 minutes before anesthesia and for 30 minutes after surgery. Current intensity will be adjusted between 2 and 6 mA according to participant tolerance.
干预措施: Transauricular Vagus Nerve Stimulation (tVNS) (Device)
Low-Frequency tVNS
Participants will receive active transauricular vagus nerve stimulation (tVNS) at a frequency of 10-20 Hz. Stimulation will be applied bilaterally to the auricular branch of the vagus nerve for 30 minutes before anesthesia and for 30 minutes after surgery. Current intensity will be adjusted between 2 and 6 mA according to participant tolerance.
干预措施: Transauricular Vagus Nerve Stimulation (tVNS) (Device)
研究者
Joao Paulo Aureliano de Carvalho
Researcher, Department of Anesthesiology and Surgery
Federal University of Bahia