Randomized Clinical Trial
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Dec 16, 2022; 14(12): 777-788
Published online Dec 16, 2022. doi: 10.4253/wjge.v14.i12.777
High-flow oxygen via oxygenating mouthguard in short upper gastrointestinal endoscopy: A randomised controlled trial
Kim Hay Be, Leonardo Zorron Cheng Tao Pu, Brett Pearce, Matthew Lee, Luke Fletcher, Rebecca Cogan, Philip Peyton, Rhys Vaughan, Marios Efthymiou, Sujievvan Chandran
Kim Hay Be, Leonardo Zorron Cheng Tao Pu, Rhys Vaughan, Marios Efthymiou, Sujievvan Chandran, Department of Gastroenterology and Hepatology, Austin Health, Heidelberg 3084, Victoria, Australia
Brett Pearce, Matthew Lee, Luke Fletcher, Rebecca Cogan, Philip Peyton, Department of Anaesthesia and Pain Medicine, Austin Health, Heidelberg 3084, Victoria, Australia
Brett Pearce, Matthew Lee, Philip Peyton, Rhys Vaughan, Marios Efthymiou, Sujievvan Chandran, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville 3010, Victoria, Australia
Sujievvan Chandran, Faculty of Medicine, Nursing and Health Sciences, Monash University, Frankston 3199, Victoria, Australia
Author contributions: Be KH, Zorron Cheng Tao Pu L, Peyton P, Efthymiou M, Vaughan R, and Chandran S conceptualized and designed the study; all authors were involved in data collection, analyses, or both; all authors were involved in the interpretation of the results; Be KH, Zorron Cheng Tao Pu L, Lee M, Fletcher L and Chandran S drafted the manuscript; Pearce B, Cogan R, Efthymiou M, and Vaughan R carried the critical revision of the article for important intellectual content; and all authors read and approved the final version of the manuscript.
Institutional review board statement: The study was reviewed and approved by the Austin Health Human Research Ethics Committee (ND 63130/2020).
Clinical trial registration statement: This study is registered at ANZCTR.org.au. The registration identification number is ACTRN12620000930987.
Informed consent statement: All study participants, or their legal guardians, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: The authors disclose no conflicts of interest.
Data sharing statement: No additional data are available.
CONSORT 2010 statement: The authors have read the CONSORT 2010 statement, and the manuscript was prepared and revised according to the CONSORT 2010 statement.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Kim Hay Be, MBBS, Doctor, Department of Gastroenterology and Hepatology, Austin Health, 145 Studley Road, Heidelberg 3084, Victoria, Australia. kim.be@austin.org.au
Received: September 18, 2022
Peer-review started: September 18, 2022
First decision: October 19, 2022
Revised: October 26, 2022
Accepted: November 9, 2022
Article in press: November 9, 2022
Published online: December 16, 2022
Processing time: 86 Days and 22.6 Hours
ARTICLE HIGHLIGHTS
Research background

Anaesthetic care during upper gastrointestinal (GI) endoscopy has the unique challenges of balancing adequate patient sedation while maintaining sufficient ventilation and oxygenation via a shared upper airway. Supplementary oxygen during upper GI endoscopy under deep sedation is considered the standard practice to reduce the incidence and severity of hypoxaemia. However, despite this being a recommendation of international society guidelines, the optimal route or rate of oxygen delivery is not known.

Research motivation

Various oxygen delivery devices have been investigated to improve oxygenation during upper GI endoscopy, however, these are limited by commercial availability, costs and in some cases, the expertise required for insertion. Anecdotally at our centre, higher flows of supplemental oxygen can safely be delivered via an oxygenating mouthguard. This oxygenating mouthguard is routinely used during upper GI endoscopic procedures in our practice and as such offers a practical solution to reducing the incidence and severity of hypoxaemia in patients undergoing upper GI endoscopic procedures under deep sedation.

Research objectives

To assess the incidence of hypoxaemia (SpO2 < 90%) in patients undergoing upper GI endoscopy receiving supplemental oxygen using an oxygenating mouthguard at 20 L/min flow compared to standard nasal cannula (SNC) at 2 L/min flow as a proof-of-concept study.

Research methods

A single centre, prospective, randomised clinical trial at two sites of an Australian tertiary hospital between October 2020 and September 2021 was conducted. Patients undergoing elective upper gastrointestinal endoscopy under deep sedation were randomised to receive supplemental oxygen via high-flow via oxygenating mouthguard (HFMG) at 20 L/min flow or SNC at 2 L/min flow. The primary outcome was the incidence of hypoxaemia of any duration measured by pulse oximetry. Intraprocedural-related, procedural-related, and sedation-related adverse events and patient-reported outcomes were also recorded.

Research results

Three hundred patients were randomised. Eight patients were excluded after randomisation. 292 patients were included in the intention-to-treat analysis. The incidence of hypoxemia was significantly reduced in those allocated HFMG. Six patients (4.4%) allocated to HFMG experienced an episode of hypoxaemia, compared to thirty-four (22.1%) patients allocated to SNC (P value < 0.001). No significant difference was observed in the rates of adverse events or patient-reported outcome measures.

Research conclusions

The use of HFMG offers a novel approach to reducing the incidence of hypoxaemia during short upper gastrointestinal endoscopic procedures in low-risk patients undergoing deep sedation.

Research perspectives

Additional studies using different flows through the oxygenating mouthguard would be warranted to elucidate the mechanisms by which HFMG reduces the incidence of hypoxaemia in patients undergoing upper GI endoscopy. Further comparative studies are required to determine the cost-effectiveness of HFMG in upper GI endoscopy compared to high-flow nasal cannula and other airway devices.