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

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

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.

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.

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.