Brief Summary：Video-assisted thoracoscopic surgery (VATS) has a wide range of applications, including the diagnosis and treatment of lung cancer, and has gradually replaced traditional open thoracotomy. VATS must routinely employ single-lung ventilation techniques. During single-lung ventilation, mechanical injury, lung collapse, imbalance in the ventilation-perfusion ratio, ischemia-reperfusion, and other pathological physiological changes may occur, leading to the release of a large number of inflammatory factors, triggering local and systemic inflammatory responses,increasing the incidence of postoperative complications, and affecting patient outcomes. Additionally, most patients undergoing thoracoscopic surgery experience acute postoperative pain. If acute postoperative pain is not adequately controlled, it may progress to chronic pain, affecting the quality of postoperative recovery. Currently, opioid medications are the primary drugs used to treat moderate to severe postoperative pain. However, adverse events associated with opioid medications may also affect the quality of postoperative recovery.The use of multimodal analgesia for postoperative pain management can control pain and reduce the need for opioid medications.

Esketamine, a newly marketed intravenous anesthetic in China in recent years, is the dextrorotatory isomer of ketamine, and acts as a non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor. Compared to ketamine, esketamine has higher potency, faster recovery time, and fewer adverse effects. Some clinical studies have shown that administration of esketamine reduces the intensity of postoperative pain and decreases the need for postoperative analgesics. Research has found that esketamine reduces the consumption of opioid medications and hyperalgesia postoperatively. Additionally, studies have shown that esketamine administration improves recovery quality by alleviating postoperative pain. Dexmedetomidine (DEX) is a selectiveα2 adrenergic receptor agonist with sedative and analgesic effects. Studies have shown that dexmedetomidine effectively reduces surgical inflammation, oxidative stress, and postoperative pain, thereby promoting postoperative recovery in surgical patients without increasing the risk of adverse reactions or complications. A meta-analysis indicated that dexmedetomidine administration alleviates postoperative pain and reduces postoperative nausea and vomiting (PONV). Current evidence suggests that the use of dexmedetomidine improves postoperative recovery quality. However, the effects of esketamine combined with dexmedetomidine on postoperative recovery quality in patients undergoing thoracoscopic surgery have not been reported. This study aims to investigate whether the combined administration of esketamine and dexmedetomidine can further improve postoperative recovery quality in patients undergoing thoracoscopic surgery.

Inclusion Criteria:

1. Age 18-65 years old;
2. BMI 18-30 kg/m2;
3. ASA classification I-III;
4. Patients undergoing thoracoscopic surgery;
5. No contraindications to the study drug;
6. Ability to express, communicate, and understand normally;
7. Both the patient and their family members agree to participate in this study and sign the informed consent form.

Exclusion Criteria:

1. Patients with poorly controlled or untreated hypertension;
2. Patients with untreated hyperthyroidism;
3. Patients with mental illness, cognitive impairment, or language barriers that prevent communication;
4. Patients with severe cardiopulmonary, hepatic, or renal dysfunction;
5. Patients with increased intracranial pressure;
6. Patients with a history of allergic reactions to any of the drugs used in the study;