Purpose:

To compare the efficacy and safety of TCI tube core and ordinary tube core assisted tracheal intubation in simulating difficult airway under visual laryngoscope, and to provide reference for clinical application

Endotracheal intubation plays an important role in contemporary clinical anesthesia. Direct laryngoscope intubation is the traditional intubation method in anesthesia and emergency medical work. However, due to the constraints of the operator's technical level, the abnormal airway structure and the condition of patients, about 1.5% ~ 8.5% of the cases of intubation difficulties occur. It's even impossible to intubate. Failure of intubation can lead to major complications, including brain damage and death. When a tracheal intubation cannot be placed on the first two attempts, the intubation is classified as difficult, and repeated routine tracheal intubation may lead to morbidity in the patient, and the incidence of airway related complications increases significantly with the number of tracheal intubations. Difficult intubation accounted for 4% of operating room intubation and 10% of intubation outside the operating room. For patients with high glottis and short epiglottis, although the glottis can be seen, intubation is difficult to place. The effectiveness and safety of TCI tube assisted intubation under visual laryngoscope and ordinary tube tube assisted intubation in simulated difficult airway were compared to provide reference for clinical application.

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.