Comparison of Video Laryngoscopy With Rigid Stylet vs Video Laryngoscopy With the TCI Articulating Introducer for Endotracheal Intubation in Simulated Difficult Airways

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.