With the aging of Chinese population, the early screening of gastrointestinal diseases and the promotion and implementation of comfortable medical treatment, more and more elderly patients choose painless gastroenteroscopy for diagnosis and treatment.However, the incidence of anesthesia-related adverse reactions and complications is high in elderly patients.Hypoxemia caused by anesthetic-induced respiratory depression and airway obstruction is a serious complication in painless gastroenteroscopy.Severe hypoxemia not only requires emergency airway intervention, such as mask ventilation or even tracheal intubation, but also leads to the interruption of endoscopic diagnosis and treatment.Advanced age was an independent risk factor for hypoxemia during painless gastroenteroscopy,This study observed the effect of a new type of oropharyngeal ventilation in improving the elderly painless gastroenteroscopy anesthesia hypoxemia and reducing intraoperative airway intervention, so as to evaluate the safety and effectiveness of a new type of nasopharyngeal ventilation in the elderly painless gastrointestinal diagnosis and treatment, and provide clinical reference.

The oropharyngeal airway is an important airway auxiliary device for short-term airway management during the perianesthetic period, which can provide patients with an unobstructed airway during autonomous ventilation .The oropharyngeal vent has been proven to be successfully used in infants, the elderly and MRI, and can be used in short outpatient surgery instead of laryngeal mask .The oropharyngeal airway has a low incidence of pharyngeal trauma and laryngeal pain immediately after surgery, requiring a shorter exposure time of inhaled anesthetic and a lower concentration of propofol to successfully place it .During the operation to preserve spontaneous breathing, the oropharyngeal airway is introduced as a ventilation device .The new oropharyngeal airway can accept the implantation of gastroscopy and provide oxygen to patients without affecting the operation at the same time. In order to explore whether the new oropharyngeal airway can provide better oxygen to patients undergoing painless gastroenteroscopy and reduce the incidence of hypoxia during the operation, we have drafted this study and explored the safety of the new oropharyngeal airway in painless gastroenteroscopy.

Inclusion Criteria:

• Age 65-80 years old
• written informed consent of patient or family member
• painless stomach + colonoscopy
• ASA grade I-II

Exclusion Criteria:

• Patients with clotting disorders or a tendency to oropharyngeal bleeding, mucosal damage or space occupation, difficulty in placing oropharyngeal airway, etc., who could not perform oropharyngeal airway ventilation;
• Upper respiratory tract infections such as mouth, nose or throat;
• Fever (core body temperature ≥37.5℃);
• a confirmed diagnosis of pregnancy or breastfeeding;
• Allergic to sedatives such as propofol or equipment such as tape;
• Emergency surgery;
• Multiple trauma;
• SpO2 < 95% before operation;
• A history of drug and/or alcohol abuse within 2 years prior to the start of the screening period;(Drinking more than three times standard alcoholic beverages per day, equivalent to about 10g of alcohol or equivalent to 50g of Chinese liquor);
• Patients with previous psychiatric and neurological diseases, such as depression, severe central nervous depression, Parkinson's disease, basal ganglia disease, schizophrenia, epilepsy, Alzheimer's disease, myasthenia gravis;
• Currently participating in other clinical trials;
• Patients who are deemed unfit by the investigator to participate in the trial;
• Patients with a history of smoking should not participate in this study.