Oropharyngeal airway integrated with capnography and oxygenation for sedated gastrointestinal endoscopy in patients with obesity: a randomized trial

Abstract

Abstract Background Hypoxia from sedation-induced upper airway obstruction remains a major risk during endoscopy in patients with obesity. Nasal cannulae provide oxygenation but do not address obstruction. The Capnography Monitoring Bite Block Oxygenation endoscopy oropharyngeal airway device (COMBO) was feasible in a pilot study, but its efficacy compared with standard care remains unclear. This multicenter randomized controlled trial (RCT) evaluated whether the COMBO device reduces hypoxia vs. standard nasal cannula (SNC) in patients with obesity undergoing sedated endoscopy. Methods In this multicenter RCT at three Chinese hospitals, adults with a body mass index ≥28 kg/m² undergoing sedated endoscopy were randomized 1:1 to the COMBO device or SNC. All patients received oxygen (6 L/min) and end-tidal carbon dioxide monitoring. The primary outcome was hypoxia (blood oxygen saturation ≥75% to <90% for <60 seconds). Results 591 patients were analyzed. The incidence of hypoxia was lower in the COMBO group than in the SNC group (6.4% [19/298] vs. 21.5% [63/293]; absolute difference, −15.1%, 95%CI −20.6 to −9.7; P < 0.001), and the incidence of subclinical respiratory depression was also lower in the COMBO group (15.1% [45/298] vs. 27.6% [81/293]; absolute difference −12.5%, 95%CI −19.1 to −6.0; P < 0.001). Severe hypoxia did not differ significantly (0% vs. 0.3% [1/293]; P > 0.99). Other sedation-related adverse events were comparable. Conclusions The COMBO device was associated with significantly less hypoxia during sedated endoscopy in patients with obesity, without increasing adverse events. By maintaining airway patency and enabling monitoring, it may provide a safe and effective strategy for high-risk patients.