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NCT Number: NCT07175155

Combination of COMBO Endoscopy Oropharyngeal Airway and HFNC Oxygenation in Sedated Gastrointestinal Endoscopy for Morbidly Obese Patients

Hypoxaemia during sedated gastrointestinal endoscopy exceeds 40 % in morbidly obese (BMI ≥ 35 kg m-²) patients. High-flow nasal cannula alone often fails because of persistent airway collapse. A recent innovation in this domain is the COMBO Endoscopy Oropharyngeal Airway-a multifaceted device that encompasses capnography monitoring, bite block , oxygenation support, and oropharyngeal airway management.The purpose of this study is to investigate whether the combination of the COMBO Endoscopy Oropharyngeal Airway and High-Flow Nasal Cannula oxygenation reduces the incidence of hypoxemia in this population.

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Key information

Conditions

Hypoxemia Digestive System Diseases Digestive System Neoplasms Esophageal Cancer Esophageal Diseases Esophageal Neoplasms Gastric Cancer Gastrointestinal Diseases Gastrointestinal Neoplasms Head and Neck Neoplasms Hypoxia Morbidly Obese Patients Neoplasms Neoplasms by Site Pathological Conditions, Signs and Symptoms Signs and Symptoms Signs and Symptoms, Respiratory Stomach Diseases Stomach Neoplasms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Peking University First Hospital, Beijing, Beijing Municipality, China

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age ≥ 18 years.
  • BMI ≥ 35 kg/m².
  • Patients undergoing gastroscopy or gastrointestinal endoscopy.
  • The estimated duration of the procedure does not exceed 45 minutes.
  • Patients have signed the informed consent form.

Exclusion criteria

  • Coagulation disorders or bleeding tendency (e.g., oral/nasal bleeding risk, mucosal injury, oropharyngeal obstruction) making oropharyngeal airway placement unsafe or unfeasible.
  • Active upper respiratory tract infection (oral, nasal, or pharyngeal), or fever (core temperature >37.5°C).
  • Chronic obstructive pulmonary disease or other acute/chronic pulmonary diseases requiring long-term or intermittent oxygen therapy, or preoperative SpO₂ ≤ 92% on room air.
  • Severe organ dysfunction, including: Cardiac insufficiency (<4 METs), Severe renal insufficiency (requiring dialysis), Diagnosed severe hepatic insufficiency, Increased intracranial pressure, ASA physical status ≥ IV.
  • Confirmed pregnancy or current breastfeeding.
  • Known allergy to sedatives (e.g., propofol) or medical adhesives.
  • Multiple traumatic injuries.
  • Current participation in another clinical trial.
  • Other conditions deemed unsuitable by the investigator.

Treatment and study plan

COMBO Endoscopy Oropharyngeal Airway with High-Flow Nasal Cannula Oxygenation

Device

Using the COMBO endoscopy oropharyngeal airway with High-Flow Nasal Cannula Oxygenation in sedated gastrointestinal endoscopy for morbidly obese patients

High-flow nasal cannula oxygenation

Device

In this group, patients use high-flow nasal cannula oxygenation

Primary outcomes

  1. The incidence of hypoxemia

    Time frame: Patients will be followed for the duration of hospital stay, an expected average about 2 hours

    75% ≤ SpO2 < 90% for <60 s

Secondary outcomes

  1. The incidence of sub-clinical respiratory depression

    Time frame: Patients will be followed for the duration of hospital stay, an expected average about 2 hours

    90% ≤ SpO2 < 95%

  2. The incidence of severe hypoxaemia

    Time frame: Patients will be followed for the duration of hospital stay, an expected average about 2 hours

    SpO2 < 75% or 75% ≤ SpO2 < 90% for ≥60 s

Other outcomes

  1. The incidence of other adverse events

    Time frame: Patients will be followed for the duration of hospital stay, an expected average about 2 hours.

    Other adverse events recorded by tools proposed by the World Society of Intravenous Anesthesia International Sedation Task Force

Study contacts

Contact information is provided by the study sponsor or research team.

Diansan Su, Chief Physician

CONTACT

[email protected]

+8618616514088

Mingxia Xu

CONTACT

[email protected]

+8613516713435

Sponsors and collaborators

Lead sponsor

Zhejiang University

Other

Registry information

Official study title

Combination of COMBO Endoscopy Oropharyngeal Airway and High-flow Nasal Cannula Oxygenation in Sedated Gastrointestinal Endoscopy for Morbidly Obese Patients: a Multicenter, Randomized, Controlled Clinical Trial

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Sep 16, 2025
Registry last updated
Mar 11, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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