Eligibility Criteria:
Inclusion Criteria:
1. Men ≥18 years of age or non-pregnant women;
2. For elective gynecological surgery or upper abdominal surgery under general anesthesia by oral tracheal intubation, the operation position was supine and the operation time was less than 3 hours;
3. Subject's American Society of Anesthesiologists physical status is I-III
4. Subjects who could understand the purpose of the trial, voluntarily participated and signed the informed consent form, and were willing to accept the designated follow-up.
Exclusion Criteria:
1. any cerebrovascular accident, such as stroke, transient ischemic attack (TIA), etc. occurred within 3 months;
2. patients with unstable angina pectoris or myocardial infarction within 3 months;
3. laryngeal mass, obstruction, maxillofacial fracture or deformity;
4. Full stomach, high intra-abdominal pressure, habitual vomiting, gastroesophageal reflux disease;
5. pharyngeal infection, hematoma, abscess, tonsil enlargement;
6. Upper respiratory tract infection within one month, fever, cough, runny nose, nasal congestion, etc.;
7. history of chronic airway inflammation, airway hyperresponsiveness or asthma;
8. diabetic patients with severe diabetic complications (diabetic ketoacidosis, hyperosmolar coma, various infections, macroangiopathy, diabetic nephropathy, retinopathy, diabetic cardiomyopathy, diabetic neuropathy, diabetic foot, etc.);
9. severe complications of hypertension, such as arterial dissection, renal failure, cerebral hemorrhage, etc.;
10. reoperation within 3 months;
11. patients with contraindications or allergies to intraoperative drugs;
12. patients enrolled in other studies within 30 days;
13. poor adherence or the investigator's opinion that the patient was not suitable for the study.