Upper gastrointestinal endoscopy is a commonly performed diagnostic and, when necessary, therapeutic procedure in pediatric patients for the evaluation of the esophagus, stomach, and duodenum. Additional interventions such as biopsy, foreign body removal, or polypectomy can also be performed during the same session. Sedation is generally required during the procedure, and the depth of sedation is often greater than that used for routine examinations.

Because of anatomical and physiological differences in children-such as smaller airway diameter, higher oxygen consumption, and lower functional residual capacity-the risks of upper airway obstruction, hypoxemia, and hypoventilation are higher than in adults. The passage of the endoscope through the mouth, combined with the respiratory depressant effects of sedatives and the smaller airway diameter, increases the likelihood of hypoxemia and limits the anesthesia team's access to the airway. Therefore, maintaining airway stability and optimizing oxygenation during sedation are particularly critical in pediatric patients.

Currently, several oxygen delivery methods are used during upper gastrointestinal endoscopy, including conventional nasal cannulas, high-flow nasal oxygen systems, and procedural oxygen masks. The Procedural Oxygen Mask (POM™) is a specially designed device that delivers oxygen through both the mouth and nose while allowing endoscope passage and continuous capnography monitoring. Previous studies in adults have shown that the use of POM™ or high-flow nasal oxygen reduces the incidence of hypoxemia during endoscopy. However, in children, there is a lack of randomized controlled trials directly comparing POM™ with nasal cannula use.

This single-center prospective randomized controlled trial aims to compare the effectiveness of the Procedural Oxygen Mask (POM™) and nasal cannula in preventing hypoxemia during pediatric upper gastrointestinal endoscopy under sedation. The findings are expected to contribute to safer sedation practices and improved airway management strategies in pediatric endoscopic procedures.

Inclusion Criteria:

• Patients who consented to participate in the study
• Aged between 6 and 16 years
• Body weight >30 kg
• ASA physical status I-II
• Children scheduled to undergo procedural sedation for non-emergency upper gastrointestinal endoscopy

Exclusion Criteria:

• Lack of parental consent or refusal to sign the participant consent form
• History of endotracheal intubation within the past 3 months
• History of lower respiratory tract infection within the past 3 months
• History of intensive care unit (ICU) admission within the past 3 months
• Presence of a tracheostomy
• History of tracheostomy placement
• Patients with oxygen dependency due to any underlying disease
• Known pulmonary or cardiac disease
• Known congenital craniofacial anomalies
• Congenital or acquired upper airway malformations

Data will be made available upon reasonable request.