Endoscopic retrograde cholangiopancreatography (ERCP) is a technique for evaluating the bile duct, pancreatic duct, and ampulla. Hypoxia is the most common cardiopulmonary complication during ERCP, with a reported rate of 16.2 to 39.2%. The key to preventing hypoxia is to ensure the sufficient oxygenation and ventilation of patients during these procedures. The commonly used approaches to treat hypoxia with a non-instrumented airway are increasing the oxygen flow and lifting the jaw, applying with both hands, displacing the jaw upwards and anteriorly, which allowed the upper airway to remain open. We hypothesized that the supraglottic oxygen delivery via an endotracheal tube can reduce the incidence of hypoxia in patients under deep sedation during ERCP.

Inclusion Criteria:

• Age ≥18 years；
• The ASA classification ranges from I to III.
• Patients have signed the informed consent form.
• Patients scheduled to undergo sedated ERCP examination;
• The estimated duration of the procedure does not exceed 45 minutes.

Exclusion Criteria:

• Severe cardiac dysfunction (<4 METs);
• Severe renal insufficiency (requiring preoperative dialysis);
• Diagnosed chronic obstructive pulmonary disease (COPD) or other acute/chronic pulmonary diseases requiring long-term/intermittent oxygen therapy;
• Increased intracranial pressure;
• Upper respiratory tract infections (oral/nasal/pharyngeal);
• Fever (core temperature >37.5°C);
• Confirmed pregnancy or current breastfeeding;
• Allergy to sedatives (e.g., propofol) or medical adhesives;
• BMI >30 kg/m²;
• Current participation in other clinical trials;