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HypoxemiaNCT07827131

Transcutaneous Auricular Vagus Nerve Stimulation for Reducing Postoperative Hypoxemia

A study testing Transcutaneous Auricular Vagus Nerve Stimulator in people with Hypoxemia, run by Affiliated Hospital of Nantong University.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Official record
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Trial summary

Hypoxemia is a common complication in the post-anesthesia care unit (PACU) and represents one of the most meaningful factors associated with poor patient prognosis. Obese patients have a relatively higher incidence of hypoxemia. This may be partly attributable to their unique physiological characteristics. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Hypoxemia
What is being tested?
Transcutaneous Auricular Vagus Nerve Stimulator
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
80 participants
Where
No sites listed yet
Study dates
6 Sep 2026to 1 Dec 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age ≥18 years; Scheduled for elective bariatric surgery; Classified as American Society of Anesthesiologists (ASA) physical status I to III; Capable of understanding the study procedures and various assessment scales and able to effectively communicate with the researchers; Willing to participate in the study and provide written informed consent.

Who cannot join

  • Patients with severe underlying cardiopulmonary diseases (e.g., acute exacerbation of chronic obstructive pulmonary disease, acute myocardial infarction, NYHA class Ⅳ heart failure); Patients with resting SpO₂ <90% before surgery; Patients with a preoperative heart rate below 50 beats per minute or severe arrhythmia; Patients with lesions of the auricular concha (e.g., inflammation, ulcer, deformity, implant) or vagus nerve dysfunction (e.g., diabetic peripheral neuropathy, vagus nerve injury due to prior neck surgery); Patients with a history of implanted stimulators (e.g., pacemakers, implanted vagus nerve stimulators, deep brain stimulators, spinal cord stimulators), cochlear implants, or metallic implants (excluding dental work); Patients with cognitive dysfunction (MMSE score <20), psychiatric disorders, or unable to cooperate with study procedures; Patients who received vagus nerve stimulation or acupuncture within 1 month before the study; Patients with skin damage or dermatological conditions at the electrical stimulation site; Pregnant or lactating women; Patients requiring emergency surgery; Patients participating in other clinical trials.

About this study

Official title: The Effect of Transcutaneous Auricular Vagus Nerve Stimulation on the Incidence of Postoperative Hypoxemia: A Randomized Controlled Trial

Hypoxemia is a common complication in the post-anesthesia care unit (PACU) and represents one of the most meaningful factors associated with poor patient prognosis. Obese patients have a relatively higher incidence of hypoxemia. This may be partly attributable to their unique physiological characteristics. In addition, surgical trauma triggers a systemic inflammatory response with the release of pro-inflammatory factors such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). These mediators increase pulmonary capillary permeability, induce pulmonary edema, and further impair gas exchange. Surgically-induced stress elevates sympathetic tone and reduces vagal activity, which alters bronchial tone and respiratory rhythm and consequently compromises pulmonary function.Postoperative hypoxemia not only prolongs recovery time and increases the likelihood of ICU admission, but severe episodes may also lead to arrhythmia, myocardial ischemia, long-term cognitive and psychiatric disorders, and even cardiac arrest and death. These outcomes impair postoperative recovery and long-term prognosis, prolong hospital stay, and raise healthcare costs.

Although strategies such as postoperative semi-recumbent positioning and intraoperative protective ventilation have been explored, there are currently no preferred interventions or clear clinical guidelines for the prevention of postoperative hypoxemia.

Read more

As a non-invasive technique, transcutaneous auricular vagus nerve stimulation (taVNS) activates the auricular branch of the vagus nerve by stimulating the cymba conchae. Vagal activation suppresses macrophage activity and reduces the release of pro-inflammatory cytokines including TNF-α, IL-1β, IL-6 and IL-18, thereby attenuating pulmonary inflammation and edema and improving oxygenation. Afferent vagal signals project to the nucleus tractus solitarius, modulating the medullary respiratory center, respiratory rate and ventilation efficiency. taVNS is easy to perform, safe, applicable in the perioperative period, and has shown promising effects in regulating inflammatory conditions.

This study aims to investigate whether perioperative taVNS reduces the incidence of hypoxemia in the PACU by attenuating excessive sympathetic activation and mitigating pulmonary and systemic inflammatory responses.

Conditions
Hypoxemia
Being tested
Transcutaneous Auricular Vagus Nerve Stimulator
Keywords
Hypoxemia, tavns
Medical subject headings
Hypoxia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Transcutaneous Auricular Vagus Nerve StimulatorDevice

    Intervention Timing of Transcutaneous Auricular Vagus Nerve Stimulator: The intervention will begin 30 minutes before anesthesia induction and continue until the end of the surgery, terminating after the removal of the endotracheal tube in the PACU. The stimulation parameters are set as follows: frequency 20 Hz, pulse width 200 μs, 30 seconds on / 30 seconds off, with the current intensity set to the maximum amplitude the patient can tolerate (just below the pain threshold).

Study groups in NCT07827131
Study groupRoleWhat they receive
Transcutaneous auricular vagus nerve stimulation(taVNS group)ExperimentalPatients in the taVNS group will have a transcutaneous auricular vagus nerve stimulation device with a transparent, non-insulated thin film placed on the cymba conchae of the left ear. TaVNS will be administered on the day of surgery (starting 30 minutes before anesthesia induction and continuing until the end of the surgery, terminating after the removal of the endotracheal tube in the PACU). The stimulation parameters are set as follows: frequency 20 Hz, pulse width 200 μs, 30 seconds on / 30 seconds off, with the current intensity set to the maximum amplitude the patient can tolerate (just below the pain threshold).
Receives: Device: Transcutaneous Auricular Vagus Nerve Stimulator
Sham transcutaneous auricular vagus nerve stimulation(Sham taVNS group)No interventionPatients in the Sham taVNS group will have a transcutaneous auricular vagus nerve stimulation device with a transparent insulating film placed on the cymba conchae of the left ear on the day of surgery. The stimulation parameters, method, and duration will be the same as those in the taVNS group. However, due to the insulating film applied to the stimulation device in the sham group, patients will not actually receive any stimulation.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Incidence of Postoperative Hypoxemia in the PACU

    Numerous clinical studies and consensus statements define hypoxemia as either peripheral oxygen saturation (SpO₂) less than 90% lasting for more than 10 seconds, or a partial pressure of arterial oxygen to fraction of inspired oxygen (PaO₂/FiO₂) ratio less than 300 mmHg during PACU stay.

    Measured: Within 30 minutes in the PACU postoperatively

Secondary outcomes (8)

  1. Incidence and First Onset Time of Moderate Hypoxemia in the PACU

    Moderate hypoxemia is defined as SpO₂ less than 85% lasting for more than 10 seconds during PACU stay.The first onset time was defined as the time interval from extubation to the first onset of severe hypoxemia.

    Measured: Within 30 minutes in the PACU postoperatively

  2. Incidence of Airway Rescue

    Airway rescue was defined as the implementation of non-invasive mask ventilation or re-intubation for respiratory support.

    Measured: Within 30 minutes in the PACU postoperatively

  3. Time to Extubation and PACU Length of Stay

    The time interval from the end of surgical procedure to tracheal extubation. The time interval from PACU admission to PACU discharge.

    Measured: Within 30 minutes in the PACU postoperatively

  4. Postoperative Respiratory Comfort Score

    Respiratory comfort was evaluated using a 0-10 numerical rating scale, with higher scores indicating better respiratory comfort and lower scores indicating more severe respiratory discomfort.

    Measured: Within 30 minutes in the PACU postoperatively

  5. Incidence of Cough, Pulmonary Infection and Atelectasis within 24 hours after surgery

    Measured: Within the first day post-surgery

  6. Postoperative Visual Analogue Scale (VAS) pain score

    VAS scores were assessed at two states: resting state and coughing state, with scores ranging from 0 to 10 points.

    Measured: Within the first day post-surgery

  7. Total Length of Hospital Stay

    The total length of hospital stay refers to the entire duration of the hospitalization from admission to diacharge

    Measured: Up to 5 weeks postoperatively

  8. Incidence and Severity of Related Adverse Reactions

    Adverse reactions included ear skin erythema, local pain, dizziness, nausea, and bradycardia (heart rate < 50 beats per minute). The severity of adverse reactions was graded according to the following standards: Grade 1, mild discomfort without the need for clinical intervention; Grade 2, symptoms relieved after symptomatic treatment; Grade 3, severe adverse reactions requiring termination of study intervention and formal clinical treatment.

    Measured: Up to 5 weeks postoperatively

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Sep 2026
  2. Study start6 Sep 2026 (estimated)
  3. Primary completion1 Aug 2027 (estimated)
  4. Study completion1 Dec 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Outcomes assessor
Enrolment
80 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07827131
Sponsor's protocol ID
2026-K102-03
Status last verified
Sep 2026
First submitted
14 Sep 2026
Last updated
18 Sep 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A study testing Transcutaneous Auricular Vagus Nerve Stimulator in people with Hypoxemia, run by Affiliated Hospital of Nantong University.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 18 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Incidence of Postoperative Hypoxemia in the PACU (time frame: Within 30 minutes in the PACU postoperatively). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07827131.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Sep 2026.

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