There is high incidence of hemodynamic instability in patients undergoing hepatectomy with low central venous pressure, especially in general anesthesia combined with epidural anesthesia. Remazolam, a new benzodiazepine, has no significant cardiovascular inhibitory effect. Investigators hypothesis that remazolam will provide better hemodynamic when compared with propofol in patients undergoing hepatectomy with general anesthesia combined with epidural anesthesia.

Investigators plan to adopt the following strategies in the clinical study of this project: (1) To compare remazolam and propofol during anesthetic induction and maintenance; (2) Remazolam group: remazolam is administered 0.3mg/kg intravenous for anesthesia induction. Propofol group: propofol is administered 2mg/kg intravenous for anesthesia induction; (3) Epidural analgesia is used during perioperative period, and remifentanil pump injection is used during the operation to assist the subjects to tolerate the tracheal catheter; (4) the haemodynamic instability score (Hemodynamic instability score) is used to comprehensively evaluate intraoperative hemodynamic status. (5) To evaluate the incidence of postoperative complications. Through the above strategies, investigators further determine the optimization effect of remazolam, a novel benzodiazepine drug, on intraoperative hemodynamics in patients undergoing low central venous pressure hepatectomy, and further lay an empirical foundation for the routine use of remazolam in clinical hepatectomy.

Inclusion Criteria:

1. Patients who sign informed consent and are willing to complete the study according to the plan;
2. Over 18 years of age;
3. ASA grade Ⅰ ~ Ⅲ;
4. Elective surgery;
5. General anesthesia combined with epidural anesthesia;
6. Child Pugh is classified as Level A

Exclusion Criteria:

1. Abnormal coagulation function;
2. Abnormal platelet;
3. A history of drug dependence;
4. Neurological diseases;
5. Severe sinus bradycardia (HR<50 beats/min);
6. Atrial fibrillation;
7. Systolic blood pressure ≥200mmHg and/or diastolic blood pressure ≥120mmHg.
8. Cardiac insufficiency.
9. Child Pugh is classified as B or C.

The data sets are available from the corresponding author on reasonable request.