Safety and Efficacy of Maintenance of Etomidate in General Anesthesia

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.