Hysteroscopic surgery is widely used in the diagnosis and treatment of gynecological diseases. Because its operation process can cause anxiety and pain in patients, it needs to be performed under anesthesia. At present, patients under conventional non-intubation general anesthesia are prone to respiratory depression and hypoxemia. Supraglottic jet oxygen supply and ventilation (SJOV) technology can provide reliable oxygen supply and ventilation for patients with respiratory arrest and respiratory depression. It can assist in completing difficult tracheal intubation, especially in emergency airway situations where "intubation and ventilation cannot be performed". It can effectively avoid catastrophic outcomes and also prevent and reduce hypoxemia in patients undergoing day surgery. However, there are very few studies on hysteroscopic surgery. This study intends to design a single-center randomized controlled study. Patients scheduled for elective hysteroscopic surgery were randomly divided into two groups: the conventional nasal catheter ventilation group and the SJOV group. The feasibility of supraglottic jet oxygenation ventilation in hysteroscopic surgery was studied through different airway management methods. The primary outcome measure was the incidence of intraoperative hypoxemia (75%≤SpO2<90%, ≤60 seconds), and the secondary outcome measures were subclinical respiratory depression, sore throat and other adverse events. The expected result is that supragttic jet ventilation can improve the incidence of hypoxia in patients during hysteroscopy, reduce sore throat or other complications at the same time, promote patient recovery, and improve patient satisfaction.

inclusion criteria:

• Age between 18 and 65 years, with American Society of Anesthesiologists (ASA) I-II；
• Body mass index (BMI) between 18 and 28 kg/m²；
• Scheduled for elective hysteroscopic surgery under anesthesia
• Signed written informed consent

exclusion criteria:

• Any upper airway abnormalities that may cause difficult airway management, such as limited mouth opening, Mallampati Class ≥ III, and abnormal neck mobility; history of respiratory insufficiency or sleep apnea, with STOP-BANG score >3;
• Chronic alcohol abuse or drug abuse ;
• Current use of anticoagulant medications;
• Nasal, oropharyngeal infections or other contraindications for nasopharyngeal airway/WNJ insertion, including active rhinitis, recent nasal surgery, epistaxis, nasal polyps, or nasal stenosis;
• Allergy to study medications ;
• Intraoperative conversion to endotracheal intubation due to expanded surgical scope or participant's withdrawal of consent.