Multifunctional Oropharyngeal Airway and Hypoxemia in Sedated GI Endoscopy: A Multicenter RCT

Effect of a Novel Multifunctional Oropharyngeal Airway on Hypoxemia in Patients Undergoing Sedated Gastrointestinal Endoscopy: A Multicenter, Prospective, Randomized Controlled Trial

This multicenter, prospective, randomized controlled trial aims to evaluate whether a novel multifunctional oropharyngeal airway (MOPA) reduces the incidence of hypoxemia in 1,518 adult patients (ASA I-II, aged 18-80 years) undergoing elective sedated gastrointestinal endoscopy. Patients are randomized 1:1 to receive either the MOPA (which integrates oxygen delivery, PETCO₂ monitoring, and airway support) or conventional nasal cannula with standard mouthpiece. The primary endpoint is the incidence of hypoxemia (75% ≤ SpO₂ < 90% for <60 seconds) during the procedure. Secondary outcomes include severe hypoxemia, hypercapnia, PETCO₂ monitoring success, airway interventions, adverse events, and satisfaction scores. The study is conducted across 29 centers in China, with centralized randomization via an EDC system, blinded outcome assessment, and statistical analysis using a two-sided alpha of 0.05 (power 90%). Results are expected to provide high-level evidence for optimizing airway management during sedated endoscopy.

Study Overview

• Status: Not yet recruiting
• Conditions: Airway Management; Hypoxemia
• Intervention / Treatment: Device: Novel Multifunctional Oropharyngeal Airway

Detailed Description

Study Title Effect of a Novel Multifunctional Oropharyngeal Airway on Hypoxemia in Patients Undergoing Sedated Gastrointestinal Endoscopy: A Multicenter, Prospective, Randomized Controlled Trial

Principal Investigator Dr. Wu Jianbo, Department of Anesthesiology and Perioperative Medicine, The First Affiliated Hospital of Shandong First Medical University (Shandong Provincial Qianfoshan Hospital)

Participating Centers A total of 29 centers across China (including Zhejiang University First Affiliated Hospital, Hebei Medical University Second Hospital, Qilu Hospital of Shandong University, etc.)

Study Objective To evaluate whether a novel multifunctional oropharyngeal airway (MOPA) reduces the incidence of hypoxemia compared to conventional nasal cannula with standard mouthpiece in patients undergoing sedated gastrointestinal endoscopy.

Study Design Multicenter, prospective, parallel-group, randomized controlled trial.

Sample Size 1,518 patients (759 per group), accounting for a 20% dropout rate. Power: 90%, two-sided alpha: 0.05.

Participant Criteria

Inclusion: Age 18-80 years; ASA I-II; scheduled for elective sedated gastroscopy + colonoscopy; written informed consent.

Exclusion: Known respiratory disease (asthma, COPD, moderate-severe OSA, etc.); bleeding tendency or oral/nasal mucosal injury; severe cardiac/renal/hepatic dysfunction; therapeutic endoscopy (e.g., polypectomy, EMR); pregnancy; known drug allergy; emergency procedure; alcohol abuse; psychiatric illness; myasthenia gravis; participation in another trial within 3 months; refusal.

Interventions

Experimental group (MOPA): After standard sedation (fentanyl 0.05 μg/kg + propofol 1.5-2.5 mg/kg, then propofol infusion 4-12 mg/kg/h), a novel multifunctional oropharyngeal airway (integrating a bite block, oropharyngeal airway, oxygen delivery channel, and CO₂ sampling port) is inserted. Oxygen 3-4 L/min is delivered via the device, and PETCO₂ is continuously monitored through the sampling port.

Control group (conventional mouthpiece): Same sedation regimen. Patients receive oxygen 3-4 L/min via nasal cannula. PETCO₂ is monitored via nasal cannula sampling line. No oropharyngeal airway is used.

Both groups receive standardized rescue interventions for hypoxemia or ventilatory abnormalities.

Primary Endpoint Incidence of hypoxemia defined as 75% ≤ SpO₂ < 90% lasting < 60 seconds during the procedure.

Secondary Endpoints

Severe hypoxemia (SpO₂ < 75% OR 75% ≤ SpO₂ < 90% lasting ≥ 60 s)

PETCO₂ monitoring success rate (proportion with clear continuous waveform)

Detection rate of hypoventilation events (apnea ≥15-20 s; respiratory rate <8/min for ≥30 s) and early warning time before SpO₂ decline

Incidence of hypercapnia (PETCO₂ >50 mmHg or >45 mmHg for ≥30 s)

Adverse events: airway injury, regurgitation, aspiration, coughing, laryngospasm, post-procedural sore throat, hoarseness, dental/oral soft tissue injury

Airway intervention burden (jaw thrust, increased O₂ flow, procedure pause, face-mask ventilation, laryngeal mask/intubation)

Procedural efficiency (scope insertion-to-withdrawal time, number of interruptions/withdrawals due to respiratory events)

Endoscopist satisfaction (0-10 scale) and patient satisfaction (customized 0-2 per item score)

Safety Outcomes Device-related (mucosal injury, bleeding, sore throat), respiratory events (cough, laryngospasm, aspiration, need for advanced airway), systemic complications (hemodynamic instability, unplanned hospitalization/ICU), serious adverse events (refractory hypoxemia, emergency airway support, arrhythmia, myocardial ischemia, anaphylaxis, stroke).

Statistical Analysis Primary endpoint comparison using chi-square or Fisher's exact test; continuous variables using t-test or Mann-Whitney U test as appropriate. All tests two-sided, significance level α=0.05. Analysis sets: FAS, PP, SS. Missing data handled by multiple imputation where applicable.

Randomization and Blinding Centralized randomization via EDC system using stratified block randomization (block sizes 4,6,8; stratified by center). Patients are blinded to group assignment. Operators are unblinded due to device appearance. Outcome assessors and statisticians are blinded until database lock (two-stage unblinding).

Study Duration Start anticipated June 2026, completion December 2027.

Expected Publications 1-2 SCI-indexed papers reporting the primary and secondary outcomes.

• Study Type: Interventional
• Enrollment (Estimated): 1518
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: jianbo wu; Phone Number: 18560083793; Email: jianbowu@sdu.edu.cn
• Study Contact Backup: Name: 琦 尤; Phone Number: 19553100910; Email: 312011097@qq.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 18-80 years;
• BMI: 18-30 kg/m²;
• ASA class I-II;
• Scheduled to undergo elective sedated gastrointestinal endoscopy;
• Willing to participate in this study and able to provide written informed consent.

Exclusion Criteria:

• Diagnosed respiratory diseases, including asthma, bronchitis, chronic obstructive pulmonary disease (COPD), emphysema, moderate or severe obstructive sleep apnea (OSA), pulmonary embolism, pulmonary edema, lung cancer, or upper respiratory tract infection, etc.;
• Coagulation disorders, tendency for oral/nasal bleeding, mucosal injury, or space-occupying lesions;
• Severe cardiac insufficiency (≤4 MetS);
• Severe renal insufficiency (acute kidney injury [AKI] or chronic kidney disease [CKD] stage 4 or higher);
• Severe hepatic insufficiency (Child-Pugh class C or worse);
• Planned therapeutic endoscopy (e.g., polypectomy, endoscopic mucosal resection [EMR], or other therapeutic procedures);
• Pregnancy or breastfeeding;
• Allergy to the study drugs;
• Emergency surgery;
• Daily alcohol intake ≥60 grams;
• History of psychiatric disorders: e.g., depression, severe central nervous system depression, Parkinson's disease, basal ganglia lesions, schizophrenia, epilepsy, Alzheimer's disease;
• Myasthenia gravis;
• Participation in other related clinical trials within the past 3 months;
• Refusal to participate.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental group: Novel multifunctional oropharyngeal airway group; Before anesthesia, oxygen is administered via nasal cannula at 3-4 L/min, and the dedicated mouthpiece of the novel multifunctional oropharyngeal airway is inserted. After anesthesia induction and before gastroscope insertion, the anesthesiologist places the novel multifunctional oropharyngeal airway through the side of the mouthpiece and connects the oxygen supply device of the airway to deliver oxygen. The PETCO₂ sampling port of the airway is connected to the monitor to achieve continuous real-time end-tidal carbon dioxide monitoring. Insertion and fixation of the airway are completed under sedation to avoid patient discomfort.	Device: Novel Multifunctional Oropharyngeal Airway; The Novel Multifunctional Oropharyngeal Airway is an integrated airway device designed for sedated gastrointestinal endoscopy. It combines a modified mouthpiece, an oropharyngeal airway, an oxygen delivery channel, and a PETCO₂ sampling port into a single unit. The device maintains upper airway patency by preventing tongue prolapse, delivers oxygen directly to the pharynx near the glottis for more efficient oxygenation, and enables continuous real-time capnography monitoring. It is made of soft medical-grade material with anatomical curvature and depth markings to minimize mucosal injury and patient discomfort. The MOPA also reserves an interface for emergency jet ventilation if needed. It is inserted under sedation and allows the endoscope to pass smoothly through its central channel without obstruction.
No Intervention: Control group: Conventional mouthpiece group; Before anesthesia, oxygen is administered via nasal cannula at 3-4 L/min, and a conventional mouthpiece is inserted. The PETCO₂ sampling port of the nasal cannula is connected to the monitor to achieve continuous real-time end-tidal carbon dioxide monitoring. After anesthesia induction, the gastroscopy is completed without using an oropharyngeal airway.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of intraoperative hypoxemia (75% ≤ SpO₂ < 90%, duration < 60 seconds)	Incidence of intraoperative hypoxemia (75% ≤ SpO₂ < 90%, duration < 60 seconds)	Perioperative

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of severe hypoxemia (SpO₂ < 75% OR 75% ≤ SpO₂ < 90% lasting ≥ 60 seconds).	Incidence of severe hypoxemia (SpO₂ < 75% OR 75% ≤ SpO₂ < 90% lasting ≥ 60 seconds).	Perioperative
PETCO₂ monitoring success rate	proportion of participants from whom a clear, continuous PETCO₂ waveform is obtained	Perioperative
Detection rate of hypoventilation events	apnea (waveform disappearance ≥ 15-20 seconds) / bradypnea (respiratory rate < 8 breaths/min lasting ≥ 30 seconds), etc.; and the proportion of early recognition before SpO₂ decline, as well as the advanced warning time (data exported from the monitor)	Perioperative
Incidence of hypercapnia	PETCO₂ > 50 mmHg (or > 45 mmHg) lasting ≥ 30 seconds	Perioperative
Incidence of adverse events	Record all adverse events that occur during the experiment for final analysis	Perioperative
Airway intervention burden	jaw thrust/chin lift	Perioperative
Procedural efficiency	Number of withdrawals due to interruption caused by respiratory events	perioperative
Satisfaction: endoscopist satisfaction and patient satisfaction.	Note - Patient satisfaction: Each participant, in the absence of research personnel, will provide quantitative scores on predefined dimensions (pain level, foreign body sensation, comfort, quality of recovery, and overall experience). Each item is scored from 0 to 2 points, and the sum of the scores on all items will be used as the final satisfaction assessment. Endoscopist satisfaction: This is assessed using a 0-10 point scale, where 0 represents "very dissatisfied" and 10 represents "very satisfied". Based on their actual experience during the procedure, the endoscopist will select the corresponding number on the rating scale to indicate their satisfaction with the participant's cooperation and response throughout the entire procedure.	perioperative

Collaborators and Investigators

• Sponsor: Qianfoshan Hospital
• Investigators: Principal Investigator: Jianbo Wu, Doctoral, Shandong First Medical University

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2028
• Study Completion (Estimated): June 1, 2028

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 28, 2026
• First Posted (Actual): June 3, 2026

Study Record Updates

• Last Update Posted (Actual): June 3, 2026
• Last Update Submitted That Met QC Criteria: May 28, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Randomized controlled trial; Airway management; Novel multifunctional oropharyngeal airway; Capnography / PETCO₂ monitoring
• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hypoxia
• Other Study ID Numbers: YXLL-KY-2026(086)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No