Effect of Remimazolam versus Propofol on Intraoperative Norepinephrine Requirement During Thoracoscopic Pulmonary Resection: A Single-Center, Double-Blind, Randomized Controlled Trial

INTERVENTION: Intervention group:Remimazolam was administered via intravenous infusion at a rate of 6 mg/kg/h, simultaneously with fat emulsion given at a rate of 6 ml/kg/h, until consciousness was lost. Thereafter, remimazolam was continued to be infused at an initial rate of 1 mg/kg/h, with the rate adjusted in increments of 0.2 mg/kg/h.;Control group:Propofol was infused intravenously at a rate of 0.6 mg/kg/h, simultaneously with normal saline being infused at a rate of 3 ml/kg/h, until consciousness was lost. Thereafter, propofol was continued to be administered at an initial rate of 5 mg/kg/h, with the rate adjusted in increments of 1 mg/kg/h.; CONDITION: Episodes requiring norepinephrine to maintain circulatory stability during thoracoscopic pulmonary resection PRIMARY OUTCOME: Total consumption of norepinephrine during anesthesia; SECONDARY OUTCOME: Use of other vasoactive agents;Total intraoperative fluid volume;Total administered dose of remifentanil;Incidence of Myocardial Injury after Noncardiac Surgery (MINS);Incidence of intraoperative hypotension; INCLUSION CRITERIA: 1. Age >=45 years, regardless of gender, ASA physical status II‐III. 2. 18.5 kg/m^2 <= BMI <= 28 kg/m^2. 3. Scheduled for elective video‐assisted thoracoscopic lung resection surgery (including lobectomy, partial lobectomy, and wedge resection). 4. Preoperative electrocardiogram and myocardial enzyme panel (troponin, creatine kinase‐MB) are normal, with no definite history of myocardial ischemia or arrhythmias. 5. Liver and kidney function, electrolytes, and coagulation function are essentially normal. 6. Patients and their families have provided informed consent, voluntarily agree to participate in this study, and have signed the informed consent form.