This study was designed to use etomidate combined with sevoflurane intravenously to maintain anesthesia process under the monitoring of BIS. Propofol was used as the controls. Blood pressure and heart rate were recorded during operation. The VAS pain score was observed after surgery.To investigate whether this program can better maintain intraoperative hemodynamic stability, improve the quality of recovery, and reduce the incidence of postoperative adverse reactions.

Inclusion Criteria:

• 18 ≤age≤65;
• Types of surgery: laparoscopic gynecological surgery, laparoscopic gastrointestinal surgery, thoracoscopic radical lung cancer surgery;
• 1 h ≤ operation time ≤ 3 h;
• ASA grade I~III;
• BMI of 18.5~29.9 kg/m2 [BMI= weight (kg)/height (m) 2] (2013 American guidelines for the Management of Overweight and Obesity in Adults);
• In accordance with ethics, the patient voluntarily took the test and signed the informed consent.

Exclusion Criteria:

• Cerebral vascular accident, such as stroke, transient ischemic attack (TIA), etc. within 3 months;
• Severe abnormal liver and kidney function (severe abnormal liver function: ALT, AST, ALP, total bilirubin, one of which is more than 2 times the upper limit of normal value. Severe renal dysfunction: creatinine > 2 times upper normal);
• Patients with diabetic complications (diabetic ketoacidosis, hyperotonic coma, various infections, macrovascular disease, diabetic nephropathy, retinopathy, diabetic cardiomyopathy, diabetic neuropathy, diabetic foot, etc.);
• Unstable angina pectoris or myocardial infarction occurred within 3 months;
• Preoperative blood pressure ≥160/100 mmHg ( ≥ Grade 2 hypertension, 2020 ISH Hypertension Guidelines);
• Identified/suspected abuse or long-term use of narcotic sedatives and analgesics; •Taking hormones or other immunosuppressive agents for more than 10 days within half a year, or having a history of adrenocortical suppression or immune system diseases;
• Hypothyroidism;
• Patients with a history of asthma;
• Those who were reoperated within 3 months;
• Having contraindications or allergies to test drugs and other narcotic drugs;
• Patients enrolled in other studies within 30 days.