Clinical Research Directory

Inclusion Criteria: * Age ≥18 years old and \< 65 years old； * American Society of Anesthesiologists (ASA) class I-II； * Scheduled to undergo elective laparoscopic cholecystectomy undergeneral anesthesia （without epidural anesthesia, local blocks, or infiltration） Exclusion Criteria: * Pregnancy or lactation period； * BMI ≥35 kg/m² or \<18.5 kg/m²； * Anticipated difficult airway； * Previous diagnosis of hypertension； * History of drug or alcohol abuse within the past 6 months； * Preoperative acute or chronic pain history (routine preoperative use of opioid or non-opioid analgesics), peripheral or central nervous system-related disorders； * Definitively diagnosed psychiatric disorders or other neuropsychiatric conditions severely affecting cognitive judgment, history of psychotropic medication use； * Allergy or intolerance to anesthetic agents； * Baseline mean arterial pressure (MAP) \<60 mmHg or \>120 mmHg; baseline heart rate (HR) \<45 bpm or \>90 bpm (Baseline values defined as first measurement taken in the ward after admission)； * History of severe underlying diseases (untreated or ongoing peripheral/central cardiovascular diseases, severe hepatic disorders with elevated bilirubin/INR or hypoalbuminemia, severe renal diseases with elevated creatinine, severe pulmonary diseases potentially causing acute respiratory failure or persistent dyspnea)； * Implanted pacemaker, chronic arrhythmia, preoperative use of prescribed anticholinergics, α2-adrenergic agonists, beta-1 adrenergic antagonists, or antiarrhythmic medications.