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

In brief

Integrated airway device reduces hypoxia by 15% in obese patients undergoing sedated endoscopy

In a multicenter trial of 591 adults with BMI at least 28 kg/m², the COMBO oropharyngeal airway with capnography lowered the rate of oxygen desaturation (SpO₂ 75-90%) from 21.5% to 6.4% compared with standard nasal cannula. Subclinical respiratory depression also fell, while severe hypoxia and other adverse events were unchanged, suggesting a safer airway strategy for high-risk endoscopy.

Journal
Endoscopy (Q1)
Published
16 August 2026
Study design
Randomized controlled trial
Evidence level
Level 1, High (CEBM 1b)
Authors
Mingxia Xu, Saiheng Xiang, Jianhong Xu, Pingbo Xu, Yuhuan Zhu, Pengfei Huang, et al.
PMID
42604636
DOI
10.1055/a-2939-4274

Why clinicians should know about it

  • Picked for Gastroenterology (top studies of the week, 23 August 2026): Oropharyngeal airway device for sedated endoscopy in obese patients

Abstract

UNLABELLED: Background Hypoxia from sedation-induced upper airway obstruction remains a major risk during endoscopy in obese patients. Nasal cannulae provide oxygenation but do not address obstruction. The Capnography Monitoring Bite Block Oxygenation endoscopy oropharyngeal airway (COMBO device) was feasible in a pilot study, but its efficacy compared with standard care remains unclear. This multicenter RCT evaluated whether the COMBO device reduces hypoxia vs. standard nasal cannula in obese patients undergoing endoscopy. METHODS: In this multicenter RCT at three Chinese hospitals, adults with a BMI ≥28 kg/m² undergoing sedated endoscopy were randomized 1:1 to the COMBO device or standard nasal cannula. All patients received oxygen (6 L/min) and EtCO₂ monitoring. The primary outcome was hypoxia (SpO₂ 75% to < 90% for < 60 s). RESULTS: 591 patients were analyzed. The incidence of hypoxia was lower in the COMBO group than in the standard nasal cannula group (6.38% [19/298] vs. 21.50% [63/293]; absolute difference, -15.13%, 95% CI -20.59 to -9.66; P < 0.001), and the incidence of subclinical respiratory depression was also lower in the COMBO group than in the control group (15.10% [45/298] vs. 27.65% [81/293]; absolute difference -12.54%, 95% CI -19.08 to -6.01; P < 0.001). Severe hypoxia did not differ significantly (0% vs. 0.34% [1/293]; P = 0.997). Other sedation-related adverse events were comparable. CONCLUSIONS: The COMBO device was associated with significantly less hypoxia during sedated endoscopy in obese patients, without increasing adverse events. By maintaining airway patency and enabling monitoring, it may provide a safe and effective strategy for high-risk patients.

Abstract as published, via PubMed.

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For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.