Abstract
BACKGROUND: Respiratory depression and airway obstruction are the most common respiratory adverse reactions in elderly patients undergoing gastroenteroscopy under sedation. Additionally, sharing the airway with endoscopists can complicate airway management. Here, we plan to apply COMBO (Capnography Monitoring Bite Block Oxygenation) endoscopy of the oropharyngeal airway, a novel airway management device with integrated capnography monitoring and dual oxygenation support, to investigate the incidence of adverse events such as hypoxaemia and airway obstruction in elderly patients during anaesthesia, providing a reference for airway management in clinical practice. METHODS AND FINDINGS: This will be a prospective, randomized, controlled clinical study. We will enrol 164 elderly patients (aged 65-80 years) scheduled for painless gastroenteroscopy. The participants will be randomly assigned to two groups. In the experimental group, an oropharyngeal airway designed for gastroscopy will be used. The control group will receive an ordinary endoscopic bite block. The primary outcome measure will be the incidence of hypoxia (75% ≤ SpO2 < 90%, ≤ 60 s), and the secondary outcome measures will be the incidence of severe hypoxia (SpO2 < 75% or 75% ≤SpO2 < 90%, ≥ 60 s); incidence of circulatory fluctuations [severe bradycardia (< 50 beats/min), a mean arterial pressure (MAP) fluctuation greater than 30% of the baseline value or an MAP < 60 mmHg]; incidence of airway intervention; dose of additional drugs administered during the procedure; endoscopist satisfaction; and incidence of various adverse events. RESULTS: This clinical study aims to evaluate whether an oropharyngeal airway dedicated to gastroscopy can effectively maintain airway patency and alleviate retrolingual collapse, thereby preventing hypoxaemia. It also aims to determine whether it can reduce the incidence of respiratory-related adverse events. TRIAL REGISTRATION: This clinical trial protocol was formally registered at ClinicalTrials.gov (Registration Number: NCT06711328) on November 26, 2024.