RecruitingDevice studyHigh-Flow Nasal Cannula for Preventing Hypoxia During Sedated Endoscopy in High-Risk Obstructive Sleep Apnea PatientsHypoxia represents the most frequent adverse event during propofol-sedated gastrointestinal endoscopy. The STOP-BANG questionnaire serves as a widely adopted, straightforward tool for screening obstructive sleep apnea (OSA) risk, with a score ≥5 identifying high-risk OSA patients who are particularly susceptible to hypoxia under sedation. Although preliminary research from our team suggests that High-Flow Nasal Cannula (HFNC) may lower the incidence of hypoxemia, evidence remains limited and inconsistent in studies specifically targeting high-risk OSA populations. Therefore, this multicenter randomized controlled trial aims to evaluate whether HFNC can effectively reduce the occurrence of hypoxia during sedated gastrointestinal endoscopy in patients identified as high-risk for OSA.