Overview

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.

Eligibility

Inclusion Criteria:

1. Aged 18-80, of either gender, requiring emergency surgery due to trauma (such as car accidents, falls, engineering accidents, etc.).
2. No confirmed PTSD before enrollment.
3. The American Society of Anesthesiologists (ASA) physical status classification is divided into grades I-III (Grade I: healthy body and normal organ function; Grade II: mild comorbidities with good functional compensation; Grade III: severe comorbidities with limited mobility but able to cope with daily activities).
4. Voluntarily sign the informed consent form and be able to cooperate with the 1-month postoperative follow-up assessment (including CAPS-5 interview, scale completion, etc.)

Exclusion Criteria:

1. Patients with severe craniocerebral or spinal cord injury, compensatory phase of hemorrhagic shock, or severe cardiovascular and cerebrovascular issues such as second-degree or higher-degree atrioventricular block, and baseline heart rate \<50 beats per minute.
2. Hepatic and renal insufficiency (transaminase \> 2 times the upper limit of normal, creatinine \> 1.5 times the upper limit of normal), coagulation dysfunction (INR \> 1.5), or history of alcohol abuse or drug dependence within the past 6 months.
3. History of neuropsychiatric disorders (such as schizophrenia, bipolar disorder), previous PTSD history, or severe visual, auditory, or language impairments, making them unable to cooperate with scale assessments.
4. Allergic to dexmedetomidine, or with damaged/infected skin at the tVNS stimulation site (cavity of the ear concha), or implanted with a cardiac pacemaker (contraindication to tVNS).
5. Pregnant or lactating women, or those who plan to receive other PTSD interventions (such as psychotherapy, anti-anxiety medications) after surgery and may withdraw from follow-up midway.