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NCT Number: NCT07476742

Effect of Transcutaneous Auricular Vagus Nerve Stimulation on Postoperative Delirium and Negative Emotions in Patients Undergoing Cardiac Surgery

A multicenter, randomized, double-blind, sham-controlled trial to investigate the effects of intraoperative transcutaneous auricular vagus nerve stimulation (taVNS) on the incidence of postoperative delirium and negative emotional states (anxiety, depression) in patients undergoing elective cardiac surgery.

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Key information

Conditions

Postoperative Delirium (POD) Anxiety Anxiety Disorders Behavior Behavioral Symptoms Cardiac Surgical Procedures Confusion Delirium Depression Emergence Delirium Mental Disorders Nervous System Diseases Neurobehavioral Manifestations Neurocognitive Disorders Neurologic Manifestations Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Postoperative Complications Signs and Symptoms

Age range

18 year–85 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

First Medical Center of Chinese PLA General Hospital, Beijing, China.

Beijing, China

About this study

Cardiac surgery is associated with a high risk of postoperative neurocognitive disorders, including delirium and negative emotional states such as anxiety and depression, which significantly impact patient recovery and long-term outcomes. This study aims to evaluate whether intraoperative taVNS, a non-invasive neuromodulation technique, can reduce the incidence and severity of these complications. Patients will be randomized to receive either active taVNS or sham stimulation during surgery. Outcomes including delirium, anxiety, depression, pain, sleep quality, recovery quality, and relevant biomarkers will be assessed postoperatively.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Aged 18 to 85 years. Scheduled for elective cardiac surgery (e.g., CABG, valve replacement/repair). NYHA cardiac function class I-III. Willing and able to provide informed consent. Expected surgery duration ≥ 2 hours.

Exclusion criteria

  • Preoperative MMSE score < 24; severe communication barriers. History of diagnosed delirium, dementia, Parkinson's disease, schizophrenia, bipolar disorder, major depressive disorder, or long-term use of psychotropic drugs.

Skin lesions, infection, or deformity of bilateral ears; history of ear surgery or nerve injury; allergy to electrode materials.

Severe arrhythmia; implanted electronic devices (e.g., pacemaker, ICD). Participation in another interventional trial within 3 months. Other conditions deemed unsuitable by investigators.

Treatment and study plan

Active taVNS

Device

Stimulation parameters: Amplitude 20 (mA), Frequency 20Hz, Pulse width 200μs, asymmetric biphasic square wave. The current is gradually increased from 10mA to a level slightly below the individual's "prickling" sensation threshold (20-60mA). Stimulation is applied to the left auricular concha for 30 minutes after anesthesia induction and for another 30 minutes after cardiopulmonary bypass weaning.

Sham taVNS Group

Device

The sham device is identical in appearance, weight, indicator lights, and operation sounds to the active device but delivers no effective electrical current. It is applied to the left auricular concha at the same time points as the active group (30 minutes after induction and 30 minutes after CPB weaning).

Primary outcomes

  1. Incidence of Postoperative Delirium

    Time frame: Within 7 days after surgery

    Postoperative delirium will be assessed using the 3-Minute Diagnostic Interview for CAM (3D-CAM) for general ward patients and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) for ICU patients, from postoperative day 1 to day 7. Diagnosis requires the presence of acute onset/fluctuating course and inattention, plus either disorganized thinking or altered level of consciousness.

Secondary outcomes

  1. Incidence and Severity of Postoperative Depression

    Time frame: Preoperative day, Postoperative day 1, 2, 3, 7, and 30

    Postoperative Anxiety Incidence and Severity: HADS-D (Hospital Anxiety and Depression Scale - Anxiety Subscale) Score.Higher score indicates greater depression severity. A score ≥ 8 is considered clinically significant for depression (per standard cutoff).

  2. Incidence and Severity of Postoperative Anxiety

    Time frame: Preoperative day, Postoperative day 1, 2, 3, 7, and 30

    Postoperative Anxiety Incidence and Severity: HADS-A (Hospital Anxiety and Depression Scale - Anxiety Subscale) Score. Higher score indicates greater anxiety severity. A score ≥ 8 is considered clinically significant for anxiety (per standard cutoff).

  3. Incidence and Severity of Postoperative Depression

    Time frame: Preoperative day, Postoperative day 1, 2, 3, 7, and 30

    Assessed using Hamilton Depression Rating Scale (HAMD-17). Scores above standard cut-offs indicate depressive states.

  4. Incidence and Severity of Postoperative Anxiety (HADS-A)

    Time frame: Preoperative day, Postoperative day 1, 2, 3, 7, and 30

    Assessed using the anxiety subscale of the Hospital Anxiety and Depression Scale (HADS-A) at specified time points. Scores above standard cut-offs indicate anxiety states.

  5. Postoperative Agitation Score

    Time frame: At the time of extubation (within 24 hours post-surgery)

    Assessed using the Riker Sedation-Agitation Scale (SAS) at the time of extubation.

  6. Postoperative Nausea and Vomiting (PONV)

    Time frame: Within 3 days after extubation

    Assessed using a Visual Analogue Scale (VAS, 0-10) within 3 days after extubation.

  7. Postoperative Pain Score

    Time frame: Postoperative day 1, 2, 3, 7, and 30

    Assessed using the Numerical Rating Scale (NRS, 0-10).

  8. Postoperative Sleep Quality

    Time frame: Postoperative day 1, 2, 3, 7, and 30

    Assessed using the Insomnia Severity Index (ISI, score 0-28).

  9. Postoperative Recovery Quality

    Time frame: Postoperative day 7 and 30

    Assessed using the Quality of Recovery-15 or QoR-40 scale.

  10. Incidence and Severity of Postoperative Anxiety (GAD-7)

    Time frame: Preoperative day, Postoperative day 1, 2, 3, 7, and 30

    Assessed using the Generalized Anxiety Disorder-7 (GAD-7) at specified time points. Scores above standard cut-offs indicate anxiety states.

  11. Incidence and Severity of Postoperative Anxiety (SAS)

    Time frame: Preoperative day, Postoperative day 1, 2, 3, 7, and 30

    Assessed using the Self-Rating Anxiety Scale (SAS) at specified time points. Scores above standard cut-offs indicate anxiety states.

Other outcomes

  1. Postoperative Quality of Life

    Time frame: Postoperative day 7 and 30

    Assessed using the EQ-5D-5L scale.

  2. Postoperative Complications

    Time frame: From surgery completion to hospital discharge or up to 30 days postoperatively

    Incidence of complications such as respiratory failure, stroke, acute kidney injury, etc.

  3. Length of Hospital Stay

    Time frame: The duration is calculated from the date of admission (Day 0) until the date of discharge. The assessment period was censored at 100 days, meaning if patients were not discharged by then, they were considered censored at that point.

    Length of Hospital Stay

  4. CRP

    Time frame: Preoperative day, end of surgery, postoperative day 1

    Perioperative Serum Biomarker: C-Reactive Protein (CRP) Levels

  5. Arterial Blood Pressure

    Time frame: Perioperative period

    Perioperative Arterial Blood Pressure

  6. Perioperative Electroencephalogram (EEG) Data

    Time frame: Intraoperative period

    Including Ai (0-100), EMG index, BSR, SEF95, α/β/γ band power.

  7. Adverse Events Related to taVNS

    Time frame: From stimulation start to postoperative day 3

    Including skin reactions, dizziness, nausea, etc.

  8. IL-6

    Time frame: Preoperative day, end of surgery, postoperative day 1

    Interleukin-6 (IL-6) Levels

  9. S100β

    Time frame: Preoperative day, end of surgery, postoperative day 1

    S100β Protein Levels

  10. BDNF

    Time frame: Preoperative day, end of surgery, postoperative day 1

    Brain-Derived Neurotrophic Factor (BDNF) Levels

  11. IL-10

    Time frame: Preoperative day, end of surgery, postoperative day 1

    Interleukin-10 (IL-10) Levels

  12. Heart Rate

    Time frame: Perioperative period

    Perioperative Heart Rate

Sponsors and collaborators

Lead sponsor

Chinese PLA General Hospital

Other

Collaborators

  • Navy General Hospital, Beijing

Registry information

Official study title

Effect of Intraoperative Transcutaneous Auricular Vagus Nerve Stimulation on Postoperative Delirium and Negative Emotional States in Patients Undergoing Cardiac Surgery: A Multicenter, Randomized, Double-Blind, Sham-Controlled Trial

Important dates

Study start
2026
Primary completion
2027
Study completion
2027
First posted
Mar 17, 2026
Registry last updated
Mar 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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