WEI NASAL JET for The Sedation of Outpatient Upper Gastrointestinal Endoscopy

Inclusion Criteria: * patients undergoing upper gastrointestinal endoscopy * age over 18 years old * Signed informed consent form Exclusion Criteria: * a blood coagulation dysfunction or have a tendency of nose bleeding * a clear diagnosis of heart disease (heart failure, angina, myocardial infarction, arrhythmia, etc.) * a clear diagnosis of lung disease (asthma, chronic obstructive pulmonary disease, pulmonary embolism, pulmonary edema, lung cancer) * pregnant * liver disease * kidney disease * increase in intracranial pressure * emergency operation * multiple trauma * American Society of Anesthesiologists (ASA) Physical Status classification above IV * with mouth, nose and throat infection