Effect of Transcutaneous Auricular Vagus Nerve Stimulation on Postoperative Opioid Consumption in Patients Undergoing Major Abdominal Surgery

December 8, 2025 updated by: Qing-he Zhou, Affiliated Hospital of Jiaxing University
This study aims to design a prospective, double-blind, randomized controlled trial to compare the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on postoperative visceral pain in patients undergoing major abdominal surgery. Participants will be randomly assigned to receive either taVNS or sham stimulation. The total consumption of opioids and other analgesics within 24 hours post-surgery in the AICU will be recorded, along with follow-up assessments of pain scores and quality of recovery scores (Qor-15) at 24 hours postoperatively.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
108

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age between 18 and 85 years, regardless of gender
  • ASA physical status classification I-III
  • Scheduled for elective major abdominal surgery under general anesthesia, with postoperative admission to the AICU for monitoring
  • Anticipated duration of stay in the AICU is approximately 24 hours

Exclusion Criteria:

  • History of vagus nerve-related diseases (such as vasovagal syncope);
  • Severe arrhythmias or implanted electronic devices such as pacemakers;
  • Skin lesions, infections, or deformities at the site of external ear stimulation;
  • Long-term preoperative use of opioid medications or sedatives;
  • Allergy to study-related medications;

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: transcutaneous vagus nerve stimulation(taVNS)
Patients received taVNS treatment immediately upon entering the AICU, with sessions occurring every 2 hours. A specialized taVNS stimulator device was used, and the left ear was cleaned with an alcohol swab or wet tissue before inserting an earplug with electrode contacts into the left ear, ensuring a snug fit. A second earplug was inserted into the right ear. The stimulation parameters were set as follows: continuous wave, frequency 20 Hz, pulse width 200 μs. Each treatment session lasted for 30 minutes.
Device: Transcutaneous auricular vagus nerve stimulation
Patients received taVNS treatment immediately upon entering the AICU, with sessions occurring every 2 hours. A specialized taVNS stimulator device was used, and the left auricle was cleaned with an alcohol swab or wet tissue before inserting an earplug with electrode contacts into the left ear, ensuring a snug fit. A second earplug was inserted into the right ear. The stimulation parameters were set as follows: continuous wave, frequency of 20 Hz, and pulse width of 200 μs. Each treatment session lasted for 30 minutes.
Placebo Comparator: Sham-stimulation
The treatment protocol was identical to that of the taVNS group. Electrodes were placed on the left auricle. After the device was activated, it either did not deliver any current or only emitted a brief sub-threshold current to simulate the sensation of device activation, without producing continuous neural stimulation.
Device: Sham Transcutaneous auricular vagus nerve stimulation
The treatment protocol was identical to that of the taVNS group. Electrodes were placed on the left auricle. After the device was turned on, it either did not output any current or only delivered a brief sub-threshold current to simulate the sensation of the device being activated, without producing continuous neural stimulation.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Total consumption of opioids
Time Frame: within 24 hours postoperatively.
Total consumption of opioids (morphine equivalent) within 24 hours postoperatively.
within 24 hours postoperatively.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Adverse events associated with taVNS
Time Frame: 24 Hours Postoperatively
Adverse events associated with taVNS (local skin irritation, dizziness, tinnitus, etc.);
24 Hours Postoperatively
The incidence of opioid-related complications
Time Frame: within 24 hours post-surgery
The incidence of opioid-related complications (such as respiratory depression, nausea and vomiting, and intestinal paralysis) within 24 hours post-surgery.
within 24 hours post-surgery
sleep quality score
Time Frame: Postoperative first-night
Postoperative first-night sleep quality score (Richards-Campbell Sleep Questionnaire, RCSQ); the score ranges from 0 to 150, with higher scores indicating better sleep quality.
Postoperative first-night
Quality of Recovery Score
Time Frame: 24 Hours Post-Operatively
Quality of Recovery Score (QoR-15) at 24 Hours Post-Operatively;The score ranges from 0 to 150 points, with higher scores indicating better postoperative recovery quality.
24 Hours Post-Operatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Affiliated Hospital of Jiaxing University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 22, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 22, 2025

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 3, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 16, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 8, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2025-LP-778

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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