Effect of Esketamine and Lidocaine on Postoperative Chronic Pain and Long-term Survival in Patients Undergoing Hepatectomy

Inclusion Criteria: 1. Aged 18-75 years; 2. Scheduled for elective hepatectomy; 3. ASA grade I-III. Exclusion Criteria: 1. Patients who have been intubated in the ICU following surgery and do not have a planned extubation within 6 hours postoperatively. 2. Patients with a body weight less than 40 kg or greater than 100 kg. 3. Patients with cardiac conduction system abnormalities (second- or third-degree atrioventricular block) or cardiac insufficiency (left ventricular ejection fraction \< 50%). 4. Patients with severe hepatic insufficiency (alanine aminotransferase \[ALT\], aspartate aminotransferase \[AST\], or bilirubin levels more than 2.5 times the upper limit of normal) or renal insufficiency (creatinine clearance rate \< 60 mL/min). 5. Patients with a known hypersensitivity to the investigational drug. 6. Patients with a history of long-term opioid abuse. 7. Patients who are unable to communicate effectively. 8. Patients with serious comorbid medical conditions, such as uncontrolled hypertension, coronary heart disease, intracranial vascular malformations, or acute asthma exacerbations. 9. Patients with a history of epilepsy or a history of manic episodes. 10. Pregnant or breastfeeding women. 11. Patients with glaucoma. 12. Patients with preoperative cognitive dysfunction, bipolar disorder, or other psychiatric disorders, including mental retardation. 13. Patients with primary liver cancer in conjunction with malignant tumors of other organs (such as lung, kidney, intestine, etc.), or those with clinical symptoms or imaging findings suggestive of distant metastasis.