High-Flow Nasal Cannula Oxygenation During Sedated Gastrointestinal Endoscopy in Patients With Chronic Obstructive Pulmonary Disease

High-Flow Nasal Cannula Oxygenation During Sedated Gastrointestinal Endoscopy in Patients With Chronic Obstructive Pulmonary Disease: A Single-Arm Simon Two-Stage Study

Hypoxemia is the most common adverse event during propofol sedation for gastrointestinal endoscopy in patients with chronic obstructive pulmonary disease (COPD) due to diminished pulmonary reserve. Although high-flow nasal cannula (HFNC) oxygenation has been shown to effectively reduce hypoxemia during sedated endoscopy in obese patients, its application in COPD patients remains an evidence gap, largely owing to the traditional concern that high-concentration oxygen may suppress respiratory drive and exacerbate CO₂ retention. This study aims to investigate whether HFNC can reduce the incidence of hypoxemia during sedated gastrointestinal endoscopy in patients with COPD.

Inclusion Criteria:

• Age ≥18 years;
• Confirmed diagnosis of chronic obstructive pulmonary disease (COPD);
• Scheduled for elective sedated gastroenteroscopy (gastroscopy, colonoscopy, or combined gastroscopy and colonoscopy);
• Expected procedure duration ≤45 minutes;
• Provision of written informed consent by the participant.

Exclusion Criteria:

• Patients with absolute contraindications to high-flow therapy, including but not limited to confirmed diagnosis of complete upper airway obstruction, basilar skull fracture or nasal bone fracture, pneumothorax, or pneumomediastinum.;
• American Society of Anesthesiologists (ASA) Physical Status class ≥ IV;
• Requirement for planned endotracheal intubation;
• Existing tracheostomy;
• Confirmed pregnancy or currently breastfeeding;
• Known allergy to sedative agents such as propofol;
• Current participation in another interventional clinical trial;
• Any other condition deemed by the investigator to make the patient unsuitable for trial participation.