taVNS

Emergency trauma surgery patients, due to the dual stress effects of sudden trauma events (such as car accidents, falls, engineering accidents) and surgical trauma, have a significantly higher incidence of post-traumatic stress disorder (PTSD) compared to the general population. This disease, characterized by intrusive memories, avoidance behaviors, negative changes in cognitive emotions, and increased arousal, not only severely hinders patients' postoperative psychological recovery and reduces their quality of life, but may also prolong hospital stays, increase the risk of readmission, and impose a heavy medical and economic burden on families and society. Dexmedetomidine, as a highly selective α₂-adrenergic receptor agonist, possesses sedative, anxiolytic, analgesic, and sympatholytic effects. By regulating the locus coeruleus-norepinephrine system, it can alleviate perioperative stress responses, reduce postoperative anxiety and delirium incidence. In recent years, multiple studies both domestically and internationally have confirmed its potential to prevent PTSD by inhibiting the encoding and consolidation processes of trauma-related memories. In randomized clinical trials, administering dexmedetomidine during and after surgery has been shown to reduce the incidence of PTSD in trauma patients. However, when used alone, some patients still develop PTSD, indicating room for improvement in preventive efficacy. Additionally, there are risks of adverse reactions such as hypotension and bradycardia, which limit its application in certain populations. As a non-invasive vagus nerve stimulation technique, transcutaneous vagus nerve stimulation (taVNS) exerts its effect by stimulating the vagus nerve branches in the cavum concha. It has the advantages of simple operation, high safety, and can be implemented during the perioperative period. It has been proven to regulate the stress response and emotional processing of the central nervous system, reduce stress response scores, and has the potential for perioperative analgesia. However, there is limited research on its early prevention after emergency trauma surgery, and no exploration of synergistic effects with dexmedetomidine. Currently, there is no clinical research on the use of dexmedetomidine combined with taVNS for the prevention of post-traumatic stress disorder (PTSD) in patients undergoing emergency trauma surgery at home and abroad. Existing research mostly focuses on single drugs or single neuroregulation techniques, and there are limitations such as small sample size, short follow-up time, and uncontrolled confounding factors such as perioperative pain and delirium, making it difficult to meet the clinical demand for efficient and safe PTSD prevention schemes.

This study investigates the effects of transcutaneous auricular vagus nerve stimulation (taVNS) on cognitive performance in healthy adults. The study uses a sham-controlled, cross-over design in which each participant receives both active taVNS and sham stimulation in separate sessions. Each participant completes both conditions (active and sham) in a randomized order using a crossover design. Cognitive performance will be assessed before and after each session using standardized tests. The study also explores whether males and females respond differently to taVNS, in order to identify potential sex-related differences in cognitive outcomes.