Clinical Efficacy of COMBO endoscopy oropharyngeal airway in Elderly Patients Undergoing Painless Gastroenteroscopy Under Anesthesia: A Randomized Controlled Trial Protocol

Clinical Efficacy of COMBO endoscopy oropharyngeal airway in Elderly Patients Undergoing Painless Gastroenteroscopy Under Anesthesia: A Randomized Controlled Trial Protocol | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Study protocol Clinical Efficacy of COMBO endoscopy oropharyngeal airway in Elderly Patients Undergoing Painless Gastroenteroscopy Under Anesthesia: A Randomized Controlled Trial Protocol Qi You, Yang Meng, Xiaojing Liu, Chuanyu Sun, Jianbo Wu This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6094966/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 26 Sep, 2025 Read the published version in BMC Anesthesiology → Version 1 posted 9 You are reading this latest preprint version Abstract Background Respiratory depression and airway obstruction are the most common respiratory adverse reactions in elderly patients undergoing gastroenteroscopy under sedation. Additionally, sharing the airway with endoscopists can complicate airway management. Here, we apply COMBO endoscopy oropharyngeal airway, a novel airway management device with integrated capnography monitoring and dual oxygenation support,to investigate the incidence of adverse events such as hypoxemia and airway obstruction in elderly patients during anaesthesia, providing a reference for airway management in clinical practice. Methods and findings This will be a prospective, randomised, controlled clinical study. We will enrol 164 elderly patients (65 to ≤80 years old) scheduled for painless gastroenteroscopy. The participants will be randomly assigned to two groups. The experimental group will use an oropharyngeal airway designed for gastroscopy. The control group will receive an ordinary endoscopic bite block. The primary outcome measure will be the incidence of hypoxia (75% ≤ SpO2 < 90%, ≤60 s), and the secondary outcome measures will be the incidence of severe hypoxia (SpO2 < 75% or 75% ≤SpO2 < 90%, ≥60 seconds); incidence of circulatory fluctuations [severe bradycardia (< 50 beats/min), a mean arterial pressure (MAP) fluctuation greater than 30% of the baseline value or an MAP < 60 mmHg]; incidence of airway intervention; dose of additional drugs administered during the procedure; endoscopist satisfaction;and incidence of various adverse events. Results This clinical studyaims to evaluate whether an oropharyngeal airway dedicated to gastroscopy can effectively maintain airway patency and alleviate retrolingual collapse, thereby preventing hypoxemia. It also aims to determine whether it can reduce the incidence of respiratory-related adverse events. Trial Registration This clinical trial protocol received formal registration at ClinicalTrials.gov (Registration Number: NCT06711328) on November 26, 2024. elderly patients endoscopy oropharyngeal airway gastroenteroscopy Figures Figure 1 Figure 2 INTRODUCTION For digestive system diseases with a high incidence, timely prevention, treatment, and endoscopic examination of the digestive system are essential to detect early lesions [1] . Some studies have shown that a single colonoscopy screening can reduce the incidence and mortality of colorectal cancer within 20 years [2] . Wendy Atkin et al. reported that a single colonoscopy can provide effective protection against colorectal cancer and death for up to 17 years [3] . During endoscopy, the gastroscope enters the gastrointestinal tract through the oropharynx. Due to the high sensitivity of the pharynx, gastroscope placement commonly causes pain, nausea, and vomiting, and may even cause suffocation. Severe discomfort, such as vomiting, coughing or pain during physical movement, may worsen the original disease or interrupt the examination or treatment [4] . On one hand, painless gastroenteroscopy significantly alleviates patients' anxiety, fear, pain, and other adverse emotions [5] ; on the other, it creates an optimal environment for examination. Sedation enables patients to cooperate better with the examination, thus increasing the detection of early cancer (EC) and precancerous lesions (including high-grade intraepithelial neoplasia (HGIN)) in the upper digestive tract (UGI) and promoting implementation of a painless diagnosis and treatment. This gives patients greater satisfaction during gastroenteroscopy and a higher detection rate of early digestive system lesions [6, 7] . With increasing global aging, the proportion of elderly patients receiving gastroenteroscopy is rising, resulting in a high incidence of anaesthesia-related adverse reactions and complications, such as hypoxaemia, airway obstruction and haemodynamic fluctuations, primarily related to the respiratory and circulatory systems [8] . Advanced age is an independent risk factor for hypoxaemia in patients undergoing painless gastroenteroscopy [9, 10] . Due to the combined effects of physiological and pathological characteristics, such as reduced lung compliance, reduced alveolar active substances, reduced lung parenchymal function, and decreased respiratory reserve capacity, as well as many chronic diseases [11] , elderly patients undergoing gastroenteroscopy are more prone to varying degrees of airway obstruction or hypoxaemia caused by respiratory depression during anaesthesia [12, 13] . The intense stimulation of the pharynx by gastroscopy is likely to cause coughing, reflux aspiration, body movement, and other adverse reactions, requiring more drugs to deepen anaesthesia. Propofol is the most commonly used anaesthetic drug during gastroenteroscopy. It can inhibit the circulation and respiration of patients to varying degrees, resulting in an increased incidence of intraoperative hypoxaemia and hypotension [14, 15] . Anaesthetic drugs can also weaken the protective reflex of the digestive tract, resulting in a higher incidence of reflux, cough and aspiration during gastroenteroscopy under sedation [16] . Since the airway is shared between the anaesthesiologist and the endoscopist during gastroscopy, airway management during anaesthesia is very challenging. Additionally, most patients undergo gastroenteroscopy in the lateral position, and opening the airway through mandibular lifting is not very effective [17] ; measures such as high-flow oxygen inhalation when the airway cannot be fully opened seem unable to achieve positive outcomes [18] . Effective ventilation devices can smooth the airway and reduce the incidence of hypoxaemia and other respiratory-related complications, such as choking and laryngeal spasm. Most nasopharyngeal ventilation devices used in clinical practice are nasopharyngeal channels and nasal high-flow oxygen inhalation devices. Although they provide a good oxygen supply, they cannot directly solve upper respiratory tract obstructions, such as tongue retraction，and nasopharyngeal airways carry a risk of nasal bleeding. Compared with traditional endoscopic bite blocks, This multifunctional device (Fig.1) integrates a bite block, capnography monitoring, oxygenation support, and an innovative oropharyngeal airway design. An oropharyngeal airway is an open tongue depressor that can effectively press the tongue body without affecting the operating space of endoscopists to prevent airway obstruction caused by tongue retraction, establish an oropharyngeal airway, and provide nasal oxygen simultaneously. Moreover,this device can dual Oxygenation and Capnography Monitoring and Capable of providing Supraglottic Jet Ventilation Capability. Studies have noted that end-expiratory carbon dioxide monitoring under sedation can reduce the incidence of decreased oxygen saturation and hypoxaemia in patients undergoing colonoscopy [19-21] . Therefore, this study aims to determine the incidence of hypoxaemia and other respiratory adverse events during gastroenteroscopy in elderly patients under sedation with this novel airway management device, providing an effective reference and guidance for clinical application. MATERIALS AND METHODS Research design This will be a prospective, randomised, controlled and interventional clinical study. One hundred sixty-four elderly patients (65 ≤ 80 years) scheduled to undergo painless gastroenteroscopy in the Department of Digestive Endoscopy at the First Affiliated Hospital of Shandong First Medical University (Shandong Qianfo Hospital) will be recruited. They will be randomly divided into an experimental group (the gastroscopic oropharyngeal airway group) and a control group (the ordinary endoscope bite block group). The methods and results of this study will be reported according to the Standard Protocol Items: Recommendations for Interventional Trials 2013 statement (Additional file 1). The flow diagram for the trial is presented in Fig. 2. Inclusion criteria: 65 years old ≤ age ≤80 years old Written informed consent of the patient or their family member Painless gastroenteroscopy + colonoscopy American Society of Anesthesiologists (ASA) grade I-II Exclusion criteria A clotting disorder or a tendency toward nose and mouth bleeding, mucosal damage or space occupation, oropharyngeal airway implantation difficulties or the inability to perform oropharyngeal airway ventilation for other reasons. Severe cardiac insufficiency (≤4 MetS) Severe renal insufficiency Severe liver insufficiency Chronic obstructive pulmonary disease (COPD), other current acute or chronic pulmonary diseases, or the need for long-term or intermittent oxygen therapy Increased intracranial pressure Upper respiratory tract infections such as those of the mouth, nose, or throat Fever (core body temperature ≥37.5 degrees Celsius) History of sleep apnoea, limited mandibular extension, and the presence of airway tumours Allergy to sedatives such as propofol or devices such as tape Emergency surgery Multiple trauma Preoperative SpO2 < 95% Body mass index (BMI) ≤18.5 kg/m 2 or BMI ≥30 kg/m 2 History of drug and/or alcohol abuse within 2 years before initiation of the screening period (drinking more than three times the standard alcoholic beverages per day, equivalent to approximately 10 g of alcohol or equivalent to 50 g of Chinese liquor) Previous mental and neurological disorders, such as depression, severe central nervous system depression, Parkinson's disease, basal ganglia disease, schizophrenia, epilepsy, Alzheimer's disease, and myasthenia gravis. Current participation in other clinical trials Considered inappropriate for participation in this trial by the researchers History of smoking Sample size calculation According to the pre-experimental study of the elderly population, the incidence of hypoxia in the experimental group and the control group was 0.15 and 0.4, respectively. The sample size was calculated using PASS software, with a two-sided test level α 0.05 and a test power of 0.9. Based on the incidence of hypoxia, 65 patients will be included in each group. After considering a 20% dropout rate, 82 patients will be required in each group, for a total of 164 patients. Blinding and randomisation This study will be an open-label trial without blinding. A computer-generated randomisation sequence will randomly assign eligible patients to the control or experimental groups. Randomisation will be conducted at a 1:1 ratio. Intervention The intervention in this study will be carried out by the relevant staff of the undergraduate department participating in this clinical trial, who plan to use SAS to achieve simple randomisation grouping: COMBO endoscopy oropharyngeal airway Group (Experimental Group): From the time anaesthesia is inducted until the end of gastroscopy, a continuous oxygen supply will be provided through a catheter connected to the bite portion of the endoscope. In the regular endoscopic bite group (control group), oxygen is supplied through a regular nasal cannula before anaesthesia is induced and until the end of gastroscopy. Test process After the study participants enter the examination room, venous access will be established, and 5 ml of 2% lidocaine gel will be used to rinse their mouths and pharynx. Heart rate (HR), pulse oxygen saturation (SpO2), end expiratory carbon dioxide, electrocardiogram, and non-invasive blood pressure (measured every 2.5 minutes) will be routinely monitored before anaesthesia induction. The study participants will be instructed to lie in the left lateral position. The clinical doctors will complete the entire experimental procedure in this clinical study. Before anaesthesia induction, participants in the experimental group will receive 5–6 L/min of oxygen through an endoscopic bite device for approximately 2 minutes, whereas participants in the control group will inhale 5–6 L/min of oxygen through a nasal cannula for approximately 2 minutes. Both anaesthesia induction groups will receive 5 μg of sufentanil, followed by an intravenous injection of 1.5 mg/kg of propofol 60 seconds later. After sufficient sedation is reached (a BIS of approximately 40) in the COMBO endoscopy oropharyngeal airway group, gastroscopy will begin after the oropharyngeal airway is inserted through the endoscopic bite block. The endoscopic procedure will begin in the ordinary endoscopic bite group once sufficient sedation is achieved. Both groups will receive continuous infusions of 4 mg/kg·h propofol for anaesthesia maintenance until the procedure is completed. During the diagnosis and treatment process, if the study participants show frowning or slight body movements, intravenous propofol will be given at a dose of 40–50 mg; if the heart rate (HR) is <50 beats/min, an intravenous injection of atropine 0.5 mg will be given; if the mean arterial pressure (MAP) is < 60 mmHg, an intravenous infusion of 1 mg of hydroxylamine will be provided; and when the SpO2 is <92%, artificial airway intervention, such as chin support, assisted breathing, or a face mask, will be provided. After the procedure is complete, the patient will not leave the examination room until a MOAA/S score of 3–4 is obtained. If the discharge rating scale score exceeds 9 points after sedation/anaesthesia, the patient may be accompanied by family and friends to leave the hospital. The timing for intervention is when the end-expiratory carbon dioxide decreases by half or disappears, chest wall undulation disappears and/or when the SpO2 is less than 95%. That is, open airway techniques will be used sequentially until an SpO2 ≥ 95% is reached, and the last open airway technique is recorded. The open airway methods in the two groups will be the same: increasing the oxygen flow rate; lifting the lower jaw; providing mask ventilation (if necessary, removing the gastroscope); and performing tracheal intubation or inserting a laryngeal mask for ventilator-assisted ventilation. Primary outcome measure The main outcome measure will be the incidence of hypoxia during anaesthesia in patients undergoing painless gastroscopy (75% ≤ SpO2 < 90%, ≤ 60 s) Secondary outcome measures The secondary outcome measures will be as follows: (1) The incidence of severe hypoxia (SpO2<75% or 75% ≤ SpO2<90%, ≥); (2) The incidence of respiratory intervention procedures (measured every 60 seconds); (3) Circulation fluctuations [severe bradycardia (<50 beats/minute), MAP fluctuations with an amplitude exceeding 30% of the baseline value or an MAP<60 mmHg]; (4) The incidence of coughing, laryngeal spasm, reflux aspiration, anaesthetic dosage, diagnosis and treatment time, and awakening time (the time from the end of diagnosis and treatment to the time the patient provides an accurate answer for their name and age after awakening); and (5) Satisfaction of postoperative patients and endoscopists (0 is very dissatisfied, 10 is very satisfied). Exploratory indicators The exploratory indicators will include whether using the COMBO endoscopy oropharyngeal airway during anaesthesia in patients undergoing painless gastroscopy can effectively reduce the incidence of adverse events other than hypoxia, and the safety and effectiveness of the new airway. Remedial and supportive treatment If coughing or limb spasm occurs during the endoscopic process, 5 ml of propofol will be administered to reach the appropriate depth of anaesthesia. If severe airway spasms, ventilation disorders, and ineffective airway improvement occur during the procedure, measures such as mask pressure oxygen supply, emergency endotracheal intubation, or cricothyroid puncture will be taken. When emergencies and accidents occur during surgery, the patient will be treated as the primary focus, and their safety will be the top priority. Participants should be rescued and treated according to clinical routines. Safety evaluation procedure Participants in the study will be evaluated regarding the risks of bleeding, such as bleeding caused by oral and pharyngeal tumours, inflammation, infection, and ulcers. It is not advisable to use an airway in these patients. Termination and exit procedures Participants in the study who experience severe airway spasms, ventilation disorders, and ineffective improvement in the airway requiring emergency endotracheal intubation or cricothyroid puncture will receive life-saving measures immediately and will automatically be excluded from the trial. Statistical analysis The statistical analysis plan will be developed before the end of the experiment and finalised before the database is locked. All statistical tests, including descriptive statistics and analysis methods, will be conducted using two-sided tests, and SPSS 22 will be used for statistical analysis. For patient information, the mean ± standard deviation will be reported for continuous variables that follow a normal distribution, and a t test will be used to compare differences between groups. Variables that do not follow a normal distribution will be represented by the median (upper and lower quartiles), and a nonparametric rank sum test (Mann‒Whitney U test) will be used to compare differences between groups. For categorical variables such as the incidence of hypoxia, the frequency and rate (or composition ratio) will be reported, and the chi-square test or Fisher's exact test will be used to compare differences between groups. The main indicators will be as follows: 1) The occurrence of intraoperative hypoxia will be described in terms of frequency (incidence), and the chi-square test or Fisher’s exact test will be used to determine if there is a difference in the incidence of hypoxia between the two groups. A P value of <0.05 will indicate statistical significance, with a 95% confidence interval. 2) The following methods for handling missing data will be used: Patients with missing values will be excluded, or missing value imputation methods (such as mean imputation, maximum likelihood estimation, or multiple imputation) will be applied for missing or illogical data. Other analytical methods There are no further planned analyses in this study. DATA MANAGEMENT Analytical methods for dealing with protocol noncompliance and any statistical methods for dealing with missing data In the recruitment stage, we will give a detailed explanation of the research plan and the risks and complications that may be encountered during the trial to the study participants, obtain informed consent, minimize the withdrawal of study participants and noncompliance with the plan, and avoid data loss as much as possible. Regarding missing or illogical data, we will delete cases with missing values or use data imputation methods (e.g., mean interpolation, maximum likelihood estimation, or multiple interpolation). The plan is to provide access to the full protocol, participant-level data, and statistical code Upon reasonable request, the PI will provide interested researchers with statistical codes for analysis. In addition, in accordance with the data retention policy, all completed data will be retained for 10 years after the completion of the study. All the data will be securely stored and maintained in accordance with relevant data protection laws and regulations. Oversight and supervision of the coordination centre and the formation of the trial steering committee The Data Monitoring Committee (DMC) team is composed of clinical trial leaders, statisticians, and ethics experts. The DMC's main functions are to monitor the safety of study participants, protect the science and data integrity of the study, and make recommendations on the continuation, adjustment, or termination of the trial. Internal analysis plan for data Data entry and management are the responsibility of the designated data manager. To ensure the accuracy of the data, two data managers will independently make two copies of the input and proofread. For problems in the case report, the data manager will produce a question-and-answer sheet and send an inquiry to the investigator through the clinical ombudsman, who is expected to complete the document and return it as soon as possible. The data manager will modify, confirm and enter the data according to the researcher's answers. Adverse Event Reporting Any serious adverse events that occur during the research process, in addition to being managed promptly and effectively, will be reported to the ethics committee of the research unit by the researcher within 24 hours of becoming aware of such events. A serious adverse event form must also be completed to document the occurrence time, severity, duration, actions taken, and event outcome. Communication with the Ethics Committee This clinical trial will be conducted in accordance with ethical approval requirements. The ethics committee will be promptly informed when problems arise or if modifications to the trial protocol are necessary during the trial process. Consent is required for any changes to the experimental plan. Ethical Review and Communication The implementation of this study will adhere to the research protocol outlined in "Ethical Review Measures for Life Science and Medical Research Involving Human Subjects" (2023), the "Ethical Review Measures for Biomedical Research Involving Human Subjects" (2016), the WMA "Helsinki Declaration" (2013), the CIOMS "International Ethical Guidelines for Biomedical Research Involving Human Subjects" (2002), the "Management Measures for Investigator-Initiated Clinical Research in Medical and Health Institutions (Trial)", and all applicable laws and regulations of the country implementing the GCP ethical principles research. The research will proceed only after written approval and consent are obtained from the Ethics Committee (IRB/IEC) regarding the protocol, informed consent form, and recruitment materials/procedures for the study participants. Any modifications to the plan will also require IRB/IEC approval. The results of this study will be published in peer-reviewed journals and presented at relevant academic conferences or on research platforms. Discussion The World Health Organization predicts that the proportion of the global population aged 60 years and older will rise from 12% in 2015 to 22% in 2050 [22] . Given the aging population, it is crucial to focus on the physical health of elderly individuals and thoroughly assess their perioperative safety concerns. The incidence of related complications, such as cardiovascular adverse events, is relatively high in elderly patients during anaesthesia [23] . Studies have indicated that advanced age is an independent risk factor for hypoxemia during painless gastroscopy diagnosis and treatment [24] . Currently, propofol is used as the primary anaesthetic for gastrointestinal procedures, but its adverse reactions, such as hypoxemia, hypotension, and bradycardia [25, 26] , may be more pronounced in elderly patients. During the procedure, approximately 1.5%–70% of patients experience hypoxemia, with 36% of these cases related to respiratory pauses and 30% are related to abnormal ventilation [27] . Respiratory-related complications are a significant concern. However, sharing the airway with endoscopists focused on operating through a patient's mouth causes a considerable challenge for anaesthesiologists managing the airway. An endoscopic bite block is typically used during gastroscopy to prevent patients from biting the endoscope and their tongue. However, this block cannot maintain an open airway. Under sedation and anaesthesia, the pharynx is the primary site of airway obstruction. This may be because the pharynx is the only area not encased by the hyoid bone structure [28] , making it more prone to collapse. In addition, tongue retraction can lead to upper respiratory tract obstruction and hypoxemia. In severe cases of respiratory obstruction, considerable negative pressure can be generated in the throat [29] , increasing oesophageal pressure [30] and raising the likelihood of reflux aspiration. Studies have shown that the size of the upper airway in both males and females decreases with age [31] . When hypoxemia occurs during gastroscopy, the lower jaw may need to be lifted to clear the airway or the procedure may need to be terminated by the endoscopist. In such cases, the gastroscope is withdrawn, and oxygen is administered through a mask. The COMBO endoscopy oropharyngeal airway used for gastroscopy in our study serves as a bite block and can maintain the oropharyngeal airway without hindering the endoscopists. Moreover,the device includes oxygen supply and end-tidal carbon dioxide (CO₂) sampling channels positioned near the glottis, ensuring efficient oxygen delivery and accurate capnography readings. in addition，The oxygenation channel's specialized compatibility with high-frequency jet ventilation systems enables effective supraglottic ventilation, serving as a critical safety mechanism for managing difficult airways and respiratory compromise, thereby enhancing patient safety during procedural sedation. This study primarily aims to investigate the incidence of hypoxemia and observe the frequency of adverse respiratory events such as reflux, aspiration, and laryngeal spasm. The study's primary purpose is to determine whether this COMBO endoscopy oropharyngeal airway can effectively clear the airway, reduce the incidence of airway-related adverse events, provide a smoother anaesthetic experience, reduce the use of anaesthetic drugs, and thus reduce the incidence of anaesthesia-related complications. A more stable and safe anaesthesia environment can be provided for elderly patients undergoing gastrointestinal endoscopy. However, our study also has limitations. This will not be a multicentre, large-sample clinical study. Although stronger evidence is needed to confirm the effectiveness of this new type of the COMBO endoscopy oropharyngeal airway, more extensive clinical trials with more diverse populations will be required to validate the findings. Through the results of this study, we hope to provide a theoretical foundation and practical insights into airway management in clinical anaesthesia. This approach could be applied for anaesthesia during gastroscopy and airway management during other sedation procedures, such as bronchoscopy, providing new ideas and experiences. Abbreviations COMBO:Capnography Monitoring Bite Block Oxygenation MAP： mean arterial pressure EC： early cancer HGIN： high-grade intraepithelial neoplasia UGI： upper digestive tract SpO2: Peripheral oxygen saturation BIS: Bispectral index ASA: American Society of Anesthesiologists MetS: Metabolic Equivalents COPD: chronic obstructive pulmonary disease BMI: Body Mass Index HR: Heart rate MOAA/S: Modified observer’s alertness/sedation scale Declarations Ethics approval and consent to participate The Institutional Review Committee of the First Affiliated Hospital of Shandong First Medical University (Shandong Qianfoshan Hospital) approved the experimental protocol and performed the ethics review on August 22, 2024. The ethics number is YXLL-KY-2024(083). The results of this study will be reported in peer-reviewed journals and at relevant academic conferences or on related research platforms. In this study, participants will be recruited by distributing recruitment materials to potential participants and their family members. The experimental protocol and possible risks will be fully explained to the participants. The study participants and their family members will sign an informed consent form before anaesthesia induction. The participants will take part in this study voluntarily. The participants will not be charged any fees for the oropharyngeal vent, bite block or other consumables used in this study. During the trial, we will strictly implement the operating procedures to protect the privacy of the patients and will not disclose the patients’ information, images or personal identities. Data availability No datasets were generated or analysed during the current study. ACKNOWLEDGMENTS The authors would like to extend their gratitude to the patients participating in this trial, as well as to the medical, and research teams for their invaluable assistance in conducting this study. FUNDING The consumables that will be used in this study were all donated by Shanghai Elifu Medical Equipment Co., Ltd., under the witness of a third-party company. We are deeply grateful for the tremendous support this company has provided for this clinical trial. AUTHOR INFORMATION AUTHOR NAMES: Qi You 1 Yang Meng 2 Xiaojing Liu 3 Chuanyu Sun 4 JianboWu (corresponding author) AFFILIATIONS: Department of Anesthesiology, the First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital; Shandong Institute of Anesthesia and Respiratory Critical Medicine; Shandong Provincial Clinical Research Center for Anesthesiology. CORRESPONDING AUTHOR: Jianbo Wu; E-mail: [email protected] ; ORCID:0000-0002-9893-9096 AUTHOR CONTRIBUTIONS Jianbo Wu is the project leader and is responsible for the quality control of topic selection, design, experimental supervision and paper revision. Qi You is responsible for the design of the entire study and writing the paper. Chuanyu Sun, Xiaojing Liu and Meng Yang will contribute to the implementation and analysis of the program. ETHICS DECLARATIONS Ethics approval and consent to participate This study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Shandong First Medical University (Shandong Qianfoshan Hospital) (Approval No.YXLL-KY-2024(083)) on August 22, 2024. This clinical trial protocol received formal registration at ClinicalTrials.gov (Registration Number: NCT06711328) on November 26, 2024, prior to the enrollment of the first participant. This trial will adhere to the principles outlined in the Declaration of Helsinki, and informed written consent will be obtained from all patients. Consent for publication Not applicable. Competing interests The authors declare no competing interests. PATIENT AND PUBLIC INVOLVEMENT Patients and/or the public were not involved in the design, conduct, reporting, or dissemination plans of this research. Disclaimer: The donor of the consumables has no role in the design and implementation of the study or in the decision to write and submit this manuscript Consent for publicationNot applicable.Competing interestsThe authors declare no competing interests. References Conti CB, Agnesi S, Scaravaglio M, Masseria P, Dinelli ME, Oldani M, Uggeri F. Early Gastric Cancer: Update on Prevention, Diagnosis and Treatment. Int J Environ Res Public Health 2023, 20(3). Wooldrage K, Robbins EC, Duffy SW, Cross AJ. 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The effect of capnography on the incidence of hypoxia during sedation for EGD and colonoscopy in mildly obese patients: a randomized, controlled study. BMC Anesthesiol. 2023;23(1):188. Global burden and strength of evidence for. 88 risk factors in 204 countries and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403(10440):2162–203. Causada-Calo N, Bishay K, Albashir S, Al Mazroui A, Armstrong D. Association Between Age and Complications After Outpatient Colonoscopy. JAMA Netw Open. 2020;3(6):e208958. Leslie K, Allen ML, Hessian EC, Peyton PJ, Kasza J, Courtney A, Dhar PA, Briedis J, Lee S, Beeton AR, et al. Safety of sedation for gastrointestinal endoscopy in a group of university-affiliated hospitals: a prospective cohort study. Br J Anaesth. 2017;118(1):90–9. García Guzzo ME, Fernandez MS, Sanchez Novas D, Salgado SS, Terrasa SA, Domenech G, Teijido CA. Deep sedation using propofol target-controlled infusion for gastrointestinal endoscopic procedures: a retrospective cohort study. BMC Anesthesiol. 2020;20(1):195. Barends CRM, Driesens MK, van Amsterdam K, Struys M, Absalom AR. Moderate-to-Deep Sedation Using Target-Controlled Infusions of Propofol and Remifentanil: Adverse Events and Risk Factors: A Retrospective Cohort Study of 2937 Procedures. Anesth Analg. 2020;131(4):1173–83. Vargo JJ. 2nd: Sedation-related complications in gastrointestinal endoscopy. Gastrointest Endosc Clin N Am. 2015;25(1):147–58. Lahav Y, Rosenzweig E, Heyman Z, Doljansky J, Green A, Dagan Y. Tongue base ultrasound: a diagnostic tool for predicting obstructive sleep apnea. Ann Otol Rhinol Laryngol. 2009;118(3):179–84. Stoohs RA, Knaack L, Blum HC, Janicki J, Hohenhorst W. Differences in clinical features of upper airway resistance syndrome, primary snoring, and obstructive sleep apnea/hypopnea syndrome. Sleep Med. 2008;9(2):121–8. Loube DI, Andrada TF. Comparison of respiratory polysomnographic parameters in matched cohorts of upper airway resistance and obstructive sleep apnea syndrome patients. Chest. 1999;115(6):1519–24. Martin SE, Mathur R, Marshall I, Douglas NJ. The effect of age, sex, obesity and posture on upper airway size. Eur Respir J. 1997;10(9):2087–90. Additional Declarations No competing interests reported. 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Meng","email":"","orcid":"","institution":"Zouping People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yang","middleName":"","lastName":"Meng","suffix":""},{"id":447287883,"identity":"b051e4a4-6113-4672-b16b-8c34bc0ae92c","order_by":2,"name":"Xiaojing Liu","email":"","orcid":"","institution":"Zouping People's Hospital","correspondingAuthor":false,"prefix":"","firstName":"Xiaojing","middleName":"","lastName":"Liu","suffix":""},{"id":447287884,"identity":"64a1a2bc-85fa-4065-9ef0-8ea26e2b9c15","order_by":3,"name":"Chuanyu Sun","email":"","orcid":"","institution":"Department of Anesthesiology, the First Affiliated Hospital of Shandong First Medical University \u0026 Shandong Provincial Qianfoshan Hospital","correspondingAuthor":false,"prefix":"","firstName":"Chuanyu","middleName":"","lastName":"Sun","suffix":""},{"id":447287885,"identity":"3052fd44-b7d0-4939-8f6f-056b17b31186","order_by":4,"name":"Jianbo Wu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAzUlEQVRIiWNgGAWjYBACxmYGBmYQg5+BwYAByiZSi2QDsVoYYMoMDhCrhbmd+dnjgorDiZvPH94mwVBhndjAfvYAAYexmRvPOHM4cduNtDIJhjPpiQ08eQkEtDCYSfO23QZq4TGTYGw7nNggwWNAQAv7N7CWzf1ngFr+EaWFB2LLBoYcoJYG4rSUSc848994xo20YouEY+nGbTw5+LUY9h/fJl1QkSbb3394440PNday/exnCGhpQOYlADEbXvVAIE9IwSgYBaNgFIwCBgD5P0IHU4JbEQAAAABJRU5ErkJggg==","orcid":"","institution":"Department of Anesthesiology, the First Affiliated Hospital of Shandong First Medical University \u0026 Shandong Provincial Qianfoshan Hospital","correspondingAuthor":true,"prefix":"","firstName":"Jianbo","middleName":"","lastName":"Wu","suffix":""}],"badges":[],"createdAt":"2025-02-24 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2","display":"","copyAsset":false,"role":"figure","size":112239,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version.\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-6094966/v1/e77ef5acb50c7ba227b70bbf.png"},{"id":92430568,"identity":"074ce13b-c7ec-41c9-9bdd-d2e9bf5efc2d","added_by":"auto","created_at":"2025-09-29 16:05:59","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1213313,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6094966/v1/b3261215-4102-4b32-ac52-1767939eabf0.pdf"},{"id":82079106,"identity":"91125895-0069-4902-8861-8816ec69f5bc","added_by":"auto","created_at":"2025-05-06 14:10:32","extension":"doc","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":124486,"visible":true,"origin":"","legend":"","description":"","filename":"SPIRITFillablechecklist15Aug20132.11.doc","url":"https://assets-eu.researchsquare.com/files/rs-6094966/v1/bc6a29a2fcce982aa3a613a2.doc"}],"financialInterests":"No competing interests reported.","formattedTitle":"Clinical Efficacy of COMBO endoscopy oropharyngeal airway in Elderly Patients Undergoing Painless Gastroenteroscopy Under Anesthesia: A Randomized Controlled Trial Protocol","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eFor digestive system diseases with a high incidence, timely prevention, treatment, and endoscopic examination of\u0026nbsp;the digestive system are essential to detect early lesions \u003csup\u003e[1]\u003c/sup\u003e. Some studies have\u0026nbsp;shown that a single colonoscopy screening can reduce the incidence and mortality of colorectal cancer within 20 years\u003csup\u003e[2]\u003c/sup\u003e. Wendy Atkin et al.\u0026nbsp;reported that a single colonoscopy can provide effective protection against colorectal cancer and death for up to 17 years\u003csup\u003e[3]\u003c/sup\u003e. During endoscopy, the gastroscope enters the gastrointestinal tract through the oropharynx.\u0026nbsp;Due to the high sensitivity of the pharynx, gastroscope placement commonly causes pain, nausea, and vomiting, and may even cause suffocation. Severe discomfort, such as vomiting, coughing or pain during physical movement, may worsen the original disease or interrupt the examination or treatment\u003csup\u003e[4]\u003c/sup\u003e.\u0026nbsp;On one hand, painless gastroenteroscopy significantly alleviates patients' anxiety, fear, pain, and other adverse emotions\u003csup\u003e[5]\u003c/sup\u003e; on the other, it creates an optimal environment for examination. Sedation enables patients to cooperate\u0026nbsp;better with the examination, thus increasing the detection of early cancer (EC) and precancerous lesions (including high-grade intraepithelial neoplasia (HGIN)) in the upper digestive tract (UGI) and promoting implementation of a painless diagnosis and treatment. This gives patients greater satisfaction during gastroenteroscopy and a higher detection rate of early digestive system lesions\u003csup\u003e[6, 7]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eWith\u0026nbsp;increasing global aging, the proportion of elderly patients receiving gastroenteroscopy is rising, resulting in a high incidence of anaesthesia-related adverse reactions and complications, such as hypoxaemia, airway obstruction and haemodynamic fluctuations, primarily related to the respiratory and circulatory systems \u003csup\u003e[8]\u003c/sup\u003e. Advanced age is an independent risk factor for hypoxaemia in patients undergoing painless gastroenteroscopy\u0026nbsp;\u003csup\u003e[9, 10]\u003c/sup\u003e.\u0026nbsp;Due to the combined effects of physiological and pathological characteristics, such as reduced lung compliance, reduced alveolar active substances, reduced lung parenchymal function, and decreased respiratory reserve capacity, as well as many chronic diseases\u003csup\u003e[11]\u003c/sup\u003e, elderly patients undergoing gastroenteroscopy are more prone to varying degrees of airway obstruction or hypoxaemia caused by respiratory depression during anaesthesia\u003csup\u003e[12, 13]\u003c/sup\u003e. The intense stimulation of the pharynx by gastroscopy is likely to cause coughing, reflux aspiration, body movement, and other adverse reactions, requiring more drugs to deepen anaesthesia. Propofol is the most commonly used anaesthetic drug during gastroenteroscopy. It can inhibit the circulation and respiration of patients to varying degrees, resulting in an increased incidence of intraoperative hypoxaemia and hypotension \u003csup\u003e[14, 15]\u003c/sup\u003e. Anaesthetic drugs can also weaken the protective reflex of the digestive tract, resulting in a higher incidence of reflux, cough and aspiration during gastroenteroscopy under sedation\u0026nbsp;\u003csup\u003e[16]\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eSince the airway is shared between the anaesthesiologist and the endoscopist during gastroscopy, airway management during anaesthesia is very challenging. Additionally, most patients\u0026nbsp;undergo gastroenteroscopy in the lateral position, and opening the airway through mandibular lifting is not very effective \u003csup\u003e[17]\u003c/sup\u003e;\u0026nbsp;measures such as high-flow oxygen inhalation when the airway\u0026nbsp;cannot\u0026nbsp;be fully opened\u0026nbsp;seem\u0026nbsp;unable to achieve positive outcomes\u003csup\u003e[18]\u003c/sup\u003e. Effective ventilation devices can\u0026nbsp;smooth the airway and reduce the incidence of hypoxaemia and other respiratory-related complications, such as choking and laryngeal spasm. Most nasopharyngeal ventilation devices used in clinical practice are nasopharyngeal channels and nasal high-flow oxygen inhalation devices. Although they provide a good oxygen supply, they cannot directly solve upper respiratory tract obstructions, such as tongue retraction，and\u0026nbsp;nasopharyngeal airways carry a risk of nasal bleeding.\u003c/p\u003e\n\u003cp\u003eCompared with traditional endoscopic bite blocks,\u0026nbsp;This multifunctional device (Fig.1) integrates a bite block, capnography monitoring, oxygenation support, and an innovative oropharyngeal airway design.\u0026nbsp;An oropharyngeal airway is an open tongue depressor that can effectively press the tongue body without affecting the operating space of endoscopists to prevent airway obstruction caused by tongue retraction, establish an oropharyngeal airway, and provide nasal oxygen simultaneously. Moreover,this device can dual Oxygenation and Capnography Monitoring and Capable of providing Supraglottic Jet Ventilation Capability.\u0026nbsp;Studies have\u0026nbsp;noted that end-expiratory carbon dioxide monitoring under sedation can reduce the incidence of decreased oxygen saturation and hypoxaemia in patients undergoing colonoscopy\u0026nbsp;\u003csup\u003e[19-21]\u003c/sup\u003e.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTherefore, this study aims to determine the incidence of hypoxaemia and other respiratory adverse events during gastroenteroscopy in elderly patients under sedation with this novel airway management device, providing an effective reference and guidance for clinical application.\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cp\u003e\u003cstrong\u003eResearch design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis will be a prospective, randomised, controlled and interventional clinical study. One hundred sixty-four elderly patients (65 \u0026le; 80 years) scheduled to undergo painless gastroenteroscopy in the Department of Digestive Endoscopy at the First Affiliated Hospital of Shandong First Medical University (Shandong Qianfo Hospital) will be recruited. They will be randomly divided into an experimental group (the gastroscopic oropharyngeal airway group) and a control group (the ordinary endoscope bite block group).\u003c/p\u003e\n\u003cp\u003eThe methods and results of this study will be reported according to the Standard Protocol Items: Recommendations for Interventional Trials 2013 statement (Additional file 1). The flow diagram for the trial is presented in Fig.\u0026nbsp;2.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion criteria:\u003c/strong\u003e\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003e65 years old \u0026le; age \u0026le;80 years old\u003c/li\u003e\n\u003cli\u003eWritten informed consent of the patient or their family member\u003c/li\u003e\n\u003cli\u003ePainless gastroenteroscopy + colonoscopy\u003c/li\u003e\n\u003cli\u003eAmerican Society of Anesthesiologists (ASA) grade I-II\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion criteria\u003c/strong\u003e\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003eA clotting disorder or a tendency toward nose and mouth bleeding, mucosal damage or space occupation, oropharyngeal airway implantation difficulties or the inability to perform oropharyngeal airway ventilation for other reasons.\u003c/li\u003e\n\u003cli\u003eSevere cardiac insufficiency (\u0026le;4 MetS)\u003c/li\u003e\n\u003cli\u003eSevere renal insufficiency\u003c/li\u003e\n\u003cli\u003eSevere liver insufficiency\u003c/li\u003e\n\u003cli\u003eChronic obstructive pulmonary disease (COPD), other current acute or chronic pulmonary diseases, or the need for long-term or intermittent oxygen therapy\u003c/li\u003e\n\u003cli\u003eIncreased intracranial pressure\u003c/li\u003e\n\u003cli\u003eUpper respiratory tract infections such as those of the mouth, nose, or throat\u003c/li\u003e\n\u003cli\u003eFever (core body temperature \u0026ge;37.5 degrees Celsius)\u003c/li\u003e\n\u003cli\u003eHistory of sleep apnoea, limited mandibular extension, and the presence of airway tumours\u003c/li\u003e\n\u003cli\u003eAllergy to sedatives such as propofol or devices such as tape\u003c/li\u003e\n\u003cli\u003eEmergency surgery\u003c/li\u003e\n\u003cli\u003eMultiple trauma\u003c/li\u003e\n\u003cli\u003ePreoperative SpO2 \u0026lt; 95%\u003c/li\u003e\n\u003cli\u003eBody mass index (BMI) \u0026le;18.5 kg/m\u003csup\u003e2\u003c/sup\u003e or BMI \u0026ge;30 kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/li\u003e\n\u003cli\u003eHistory of drug and/or alcohol abuse within 2 years before initiation of the screening period (drinking more than three times the standard alcoholic beverages per day, equivalent to approximately 10 g of alcohol or equivalent to 50 g of Chinese liquor)\u003c/li\u003e\n\u003cli\u003ePrevious mental and neurological disorders, such as depression, severe central nervous system depression, Parkinson's disease, basal ganglia disease, schizophrenia, epilepsy, Alzheimer's disease, and myasthenia gravis.\u003c/li\u003e\n\u003cli\u003eCurrent participation in other clinical trials\u003c/li\u003e\n\u003cli\u003eConsidered inappropriate for participation in this trial by the researchers\u003c/li\u003e\n\u003cli\u003eHistory of smoking\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003eSample size calculation \u003c/strong\u003eAccording to the pre-experimental study of the elderly population, the incidence of hypoxia in the experimental group and the control group was 0.15 and 0.4, respectively. The sample size was calculated using PASS software, with a two-sided test level \u0026alpha; 0.05 and a test power of 0.9. Based on the incidence of hypoxia, 65 patients will be included in each group. After considering a 20% dropout rate, 82 patients will be required in each group, for a total of 164 patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBlinding and randomisation\u003c/strong\u003e This study will be an open-label trial without blinding. A computer-generated randomisation sequence will randomly assign eligible patients to the control or experimental groups. Randomisation will be conducted at a 1:1 ratio.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIntervention\u003c/strong\u003e The intervention in this study will be carried out by the relevant staff of the undergraduate department participating in this clinical trial, who plan to use SAS to achieve simple randomisation grouping:\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003eCOMBO endoscopy oropharyngeal airway Group (Experimental Group): From the time anaesthesia is inducted until the end of gastroscopy, a continuous oxygen supply will be provided through a catheter connected to the bite portion of the endoscope.\u003c/li\u003e\n\u003cli\u003eIn the regular endoscopic bite group (control group), oxygen is supplied through a regular nasal cannula before anaesthesia is induced and until the end of gastroscopy.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003eTest process\u003c/strong\u003e After the study participants enter the examination room, venous access will be established, and 5 ml of 2% lidocaine gel will be used to rinse their mouths and pharynx. Heart rate (HR), pulse oxygen saturation (SpO2), end expiratory carbon dioxide, electrocardiogram, and non-invasive blood pressure (measured every 2.5 minutes) will be routinely monitored before anaesthesia induction. The study participants will be instructed to lie in the left lateral position.\u003c/p\u003e\n\u003cp\u003eThe clinical doctors will complete the entire experimental procedure in this clinical study.\u003c/p\u003e\n\u003cp\u003eBefore anaesthesia induction, participants in the experimental group will receive 5\u0026ndash;6 L/min of oxygen through an endoscopic bite device for approximately 2 minutes, whereas participants in the control group will inhale 5\u0026ndash;6 L/min of oxygen through a nasal cannula for approximately 2 minutes. Both anaesthesia induction groups will receive 5 \u0026mu;g of sufentanil, followed by an intravenous injection of 1.5 mg/kg of propofol 60 seconds later. After sufficient sedation is reached (a BIS of approximately 40) in the COMBO endoscopy oropharyngeal airway group, gastroscopy will begin after the oropharyngeal airway is inserted through the endoscopic bite block. The endoscopic procedure will begin in the ordinary endoscopic bite group once sufficient sedation is achieved. Both groups will receive continuous infusions of 4 mg/kg\u0026middot;h propofol for anaesthesia maintenance until the procedure is completed. During the diagnosis and treatment process, if the study participants show frowning or slight body movements, intravenous propofol will be given at a dose of 40\u0026ndash;50 mg; if the heart rate (HR) is \u0026lt;50 beats/min, an intravenous injection of atropine 0.5 mg will be given; if the mean arterial pressure (MAP) is \u0026lt; 60 mmHg, an intravenous infusion of 1 mg of hydroxylamine will be provided; and when the SpO2 is \u0026lt;92%, artificial airway intervention, such as chin support, assisted breathing, or a face mask, will be provided. After the procedure is complete, the patient will not leave the examination room until a MOAA/S score of 3\u0026ndash;4 is obtained. If the discharge rating scale score exceeds 9 points after sedation/anaesthesia, the patient may be accompanied by family and friends to leave the hospital. The timing for intervention is when the end-expiratory carbon dioxide decreases by half or disappears, chest wall undulation disappears and/or when the SpO2 is less than 95%. That is, open airway techniques will be used sequentially until an SpO2 \u0026ge; 95% is reached, and the last open airway technique is recorded. The open airway methods in the two groups will be the same: increasing the oxygen flow rate; lifting the lower jaw; providing mask ventilation (if necessary, removing the gastroscope); and performing tracheal intubation or inserting a laryngeal mask for ventilator-assisted ventilation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePrimary outcome measure\u003c/strong\u003e The main outcome measure will be the incidence of hypoxia during anaesthesia in patients undergoing painless gastroscopy (75% \u0026le; SpO2 \u0026lt; 90%, \u0026le; 60 s)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSecondary outcome measures \u003c/strong\u003eThe secondary outcome measures will be as follows: (1) The incidence of severe hypoxia (SpO2\u0026lt;75% or 75% \u0026le; SpO2\u0026lt;90%, \u0026ge;); (2) The incidence of respiratory intervention procedures (measured every 60 seconds); (3) Circulation fluctuations [severe bradycardia (\u0026lt;50 beats/minute), MAP fluctuations with an amplitude exceeding 30% of the baseline value or an MAP\u0026lt;60 mmHg]; (4) The incidence of coughing, laryngeal spasm, reflux aspiration, anaesthetic dosage, diagnosis and treatment time, and awakening time (the time from the end of diagnosis and treatment to the time the patient provides an accurate answer for their name and age after awakening); and (5) Satisfaction of postoperative patients and endoscopists (0 is very dissatisfied, 10 is very satisfied).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExploratory indicators\u003c/strong\u003e The exploratory indicators will include whether using the COMBO endoscopy oropharyngeal airway during anaesthesia in patients undergoing painless gastroscopy can effectively reduce the incidence of adverse events other than hypoxia, and the safety and effectiveness of the new airway.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRemedial and supportive treatment \u003c/strong\u003eIf coughing or limb spasm occurs during the endoscopic process, 5 ml of propofol will be administered to reach the appropriate depth of anaesthesia. If severe airway spasms, ventilation disorders, and ineffective airway improvement occur during the procedure, measures such as mask pressure oxygen supply, emergency endotracheal intubation, or cricothyroid puncture will be taken. When emergencies and accidents occur during surgery, the patient will be treated as the primary focus, and their safety will be the top priority. Participants should be rescued and treated according to clinical routines.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSafety evaluation procedure \u003c/strong\u003eParticipants in the study will be evaluated regarding the risks of bleeding, such as bleeding caused by oral and pharyngeal tumours, inflammation, infection, and ulcers. It is not advisable to use an airway in these patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTermination and exit procedures \u003c/strong\u003eParticipants in the study who experience severe airway spasms, ventilation disorders, and ineffective improvement in the airway requiring emergency endotracheal intubation or cricothyroid puncture will receive life-saving measures immediately and will automatically be excluded from the trial.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe statistical analysis plan will be developed before the end of the experiment and finalised before the database is locked. All statistical tests, including descriptive statistics and analysis methods, will be conducted using two-sided tests, and SPSS 22 will be used for statistical analysis. For patient information, the mean \u0026plusmn; standard deviation will be reported for continuous variables that follow a normal distribution, and a t test will be used to compare differences between groups. Variables that do not follow a normal distribution will be represented by the median (upper and lower quartiles), and a nonparametric rank sum test (Mann‒Whitney U test) will be used to compare differences between groups. For categorical variables such as the incidence of hypoxia, the frequency and rate (or composition ratio) will be reported, and the chi-square test or Fisher's exact test will be used to compare differences between groups.\u003c/p\u003e\n\u003cp\u003eThe main indicators will be as follows: 1) The occurrence of intraoperative hypoxia will be described in terms of frequency (incidence), and the chi-square test or Fisher\u0026rsquo;s exact test will be used to determine if there is a difference in the incidence of hypoxia between the two groups. A P value of \u0026lt;0.05 will indicate statistical significance, with a 95% confidence interval. 2) The following methods for handling missing data will be used: Patients with missing values will be excluded, or missing value imputation methods (such as mean imputation, maximum likelihood estimation, or multiple imputation) will be applied for missing or illogical data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOther analytical methods \u003c/strong\u003eThere are no further planned analyses in this study.\u003c/p\u003e"},{"header":"DATA MANAGEMENT","content":"\u003cp\u003e\u003cstrong\u003eAnalytical methods for dealing with protocol noncompliance and any statistical methods for dealing with missing data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the recruitment stage, we will give a detailed explanation of the research plan and the risks and complications that may be encountered during the trial to the study participants, obtain informed consent, minimize the withdrawal of study participants and noncompliance with the plan, and avoid data loss as much as possible. Regarding missing or illogical data, we will delete cases with missing values or use data imputation methods (e.g., mean interpolation, maximum likelihood estimation, or multiple interpolation).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe plan is to provide access to the full protocol, participant-level data, and statistical code\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUpon reasonable request, the PI will provide interested researchers with statistical codes for analysis. In addition, in accordance with the data retention policy, all completed data will be retained for 10 years after the completion of the study. All the data will be securely stored and maintained in accordance with relevant data protection laws and regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOversight and supervision of the coordination centre and the formation of the trial steering committee\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Data Monitoring Committee (DMC) team is composed of clinical trial leaders, statisticians, and ethics experts. The DMC's main functions are to monitor the safety of study participants, protect the science and data integrity of the study, and make recommendations on the continuation, adjustment, or termination of the trial.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInternal analysis plan for data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData entry and management are the responsibility of the designated data manager. To ensure the accuracy of the data, two data managers will independently make two copies of the input and proofread. For problems in the case report, the data manager will produce a question-and-answer sheet and send an inquiry to the investigator through the clinical ombudsman, who is expected to complete the document and return it as soon as possible. The data manager will modify, confirm and enter the data according to the researcher's answers.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdverse Event Reporting\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAny serious adverse events that occur during the research process, in addition to being managed promptly and effectively, will be reported to the ethics committee of the research unit by the researcher within 24 hours of becoming aware of such events. A serious adverse event form must also be completed to document the occurrence time, severity, duration, actions taken, and event outcome.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommunication with the Ethics Committee\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis clinical trial will be conducted in accordance with ethical approval requirements. The ethics committee will be promptly informed when problems\u0026nbsp;arise or if modifications to the trial protocol are necessary during the trial process. Consent is required for any changes to the experimental plan.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Review and Communication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe implementation of this study will adhere to the research protocol\u0026nbsp;outlined in \"Ethical Review Measures for Life Science and Medical Research Involving Human Subjects\" (2023), the \"Ethical Review Measures for Biomedical Research Involving Human Subjects\" (2016), the WMA \"Helsinki Declaration\" (2013), the CIOMS \"International Ethical Guidelines for Biomedical Research Involving Human Subjects\" (2002), the \"Management Measures for Investigator-Initiated Clinical Research in Medical and Health Institutions (Trial)\", and all applicable laws and regulations of the country implementing the GCP ethical principles research. The research will proceed only after written approval and consent are obtained from the Ethics Committee (IRB/IEC) regarding the protocol, informed consent form, and recruitment materials/procedures for\u0026nbsp;the study participants. Any modifications to the plan will also require IRB/IEC approval. The results of this study will be published in peer-reviewed journals and presented at relevant academic conferences or on research platforms.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDiscussion\u0026nbsp;\u003c/strong\u003eThe World Health Organization predicts that the proportion of the global population aged 60\u0026nbsp;years and older will rise from 12% in 2015 to 22% in 2050\u003csup\u003e[22]\u003c/sup\u003e. Given the aging population,\u0026nbsp;it is crucial to focus on the physical health of elderly individuals and thoroughly assess their perioperative safety concerns. The incidence of related complications, such as cardiovascular adverse events, is relatively high in elderly patients during anaesthesia\u003csup\u003e[23]\u003c/sup\u003e. Studies have indicated that advanced age is an independent risk factor for hypoxemia during painless gastroscopy diagnosis and treatment\u003csup\u003e[24]\u003c/sup\u003e.\u0026nbsp;Currently, propofol is used as the primary anaesthetic for gastrointestinal procedures, but its adverse reactions, such as hypoxemia, hypotension, and bradycardia\u003csup\u003e[25, 26]\u003c/sup\u003e, may be more pronounced in elderly patients.\u003c/p\u003e\n\u003cp\u003eDuring the procedure, approximately 1.5%–70% of\u0026nbsp;patients experience hypoxemia, with 36% of these cases related to respiratory pauses and 30% are related to abnormal ventilation\u0026nbsp;\u003csup\u003e[27]\u003c/sup\u003e. Respiratory-related complications are a significant concern. However, sharing the airway with endoscopists focused on operating through a patient's mouth causes a considerable challenge for anaesthesiologists managing the airway. An endoscopic bite block is typically used during gastroscopy to prevent patients from biting the endoscope and their tongue. However, this block cannot maintain an open airway. Under sedation and anaesthesia, the pharynx is the primary site of airway obstruction. This may be because the pharynx is the only area not encased by the hyoid bone structure \u003csup\u003e[28]\u003c/sup\u003e, making it more prone to collapse. In addition, tongue retraction can lead to upper respiratory tract obstruction and hypoxemia. In severe cases of respiratory obstruction,\u0026nbsp;considerable negative pressure can be generated in the throat\u003csup\u003e[29]\u003c/sup\u003e, increasing oesophageal pressure\u003csup\u003e[30]\u003c/sup\u003e and raising the likelihood of reflux aspiration. Studies have shown that the size of the upper airway in both males and females decreases with age\u003csup\u003e[31]\u003c/sup\u003e. When hypoxemia occurs during gastroscopy, the lower jaw may need to be lifted to clear the airway or the procedure may need to be terminated\u0026nbsp;by the endoscopist. In such cases, the gastroscope is withdrawn, and oxygen is administered through a mask.\u003c/p\u003e\n\u003cp\u003eThe\u0026nbsp;COMBO endoscopy oropharyngeal airway\u0026nbsp;used for gastroscopy in our study serves as a bite block and can maintain the oropharyngeal airway without hindering the endoscopists. Moreover,the device includes oxygen supply and end-tidal carbon dioxide (CO₂) sampling channels positioned near the glottis, ensuring efficient oxygen delivery and accurate capnography readings.\u0026nbsp;in addition，The oxygenation channel's specialized compatibility with high-frequency jet ventilation systems enables effective supraglottic ventilation, serving as a critical safety mechanism for managing difficult airways and respiratory compromise, thereby enhancing patient safety during procedural sedation.\u003c/p\u003e\n\u003cp\u003eThis study\u0026nbsp;primarily aims to investigate the incidence of hypoxemia and observe the frequency of adverse respiratory events such as reflux, aspiration, and laryngeal spasm. The study's primary purpose is to determine whether this COMBO endoscopy oropharyngeal airway\u0026nbsp;can effectively clear the airway, reduce the incidence of airway-related adverse events, provide a smoother anaesthetic experience, reduce the use of anaesthetic drugs, and thus reduce the incidence of anaesthesia-related complications. A more stable and safe anaesthesia environment can be provided for elderly patients undergoing gastrointestinal endoscopy.\u003c/p\u003e\n\u003cp\u003eHowever, our study also has limitations. This will not be a multicentre, large-sample clinical study.\u0026nbsp;Although stronger evidence is needed to confirm the effectiveness of this new type of the COMBO endoscopy oropharyngeal airway, more extensive clinical trials with more diverse populations will be required to validate\u0026nbsp;the findings.\u003c/p\u003e\n\u003cp\u003eThrough the results of this study, we hope to provide a theoretical foundation and practical insights into airway management in clinical anaesthesia. This approach could be applied for anaesthesia during gastroscopy and airway management during other sedation procedures, such as bronchoscopy, providing new ideas and experiences.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCOMBO:Capnography Monitoring Bite Block Oxygenation\u003c/p\u003e\n\u003cp\u003eMAP：\u0026nbsp;mean arterial pressure\u003c/p\u003e\n\u003cp\u003eEC：\u0026nbsp;early cancer\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHGIN：\u0026nbsp;high-grade intraepithelial neoplasia\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUGI：\u0026nbsp;upper digestive tract\u003c/p\u003e\n\u003cp\u003eSpO2: Peripheral oxygen saturation\u003c/p\u003e\n\u003cp\u003eBIS: Bispectral index\u003c/p\u003e\n\u003cp\u003eASA: American Society of Anesthesiologists\u003c/p\u003e\n\u003cp\u003eMetS: Metabolic Equivalents\u003c/p\u003e\n\u003cp\u003eCOPD: chronic obstructive pulmonary disease\u003c/p\u003e\n\u003cp\u003eBMI: Body Mass Index\u003c/p\u003e\n\u003cp\u003eHR:\u0026nbsp;Heart rate\u003c/p\u003e\n\u003cp\u003eMOAA/S: Modified observer’s alertness/sedation scale\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe Institutional Review Committee of the First Affiliated Hospital of Shandong First Medical University (Shandong Qianfoshan Hospital) approved the experimental protocol and performed the ethics review on August 22, 2024. The ethics number is YXLL-KY-2024(083). The results of this study will be reported in peer-reviewed journals and at relevant academic conferences or on related research platforms.\u003c/p\u003e\n\u003cp\u003eIn this study, participants will be recruited by distributing recruitment materials to potential participants and their family members. The experimental protocol and possible risks will be fully explained to the participants. The study participants and their family members will sign an informed consent form before anaesthesia induction.\u0026nbsp;The participants will take part in this study voluntarily. The participants will not be charged any fees for the oropharyngeal vent, bite block or other consumables used in this study. During the trial, we will strictly implement the operating procedures to protect the privacy of the patients and will not disclose the patients’ information, images or personal identities.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo datasets were generated or analysed during the current study.\u0026nbsp;\u003c/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eACKNOWLEDGMENTS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe authors would like to extend their gratitude to the patients participating in this trial, as well as to the medical, and research teams for their invaluable assistance in conducting this study.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFUNDING\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe consumables that will be used in this study were all donated by Shanghai Elifu Medical Equipment Co., Ltd., under the witness of a third-party company. We are deeply grateful for the tremendous support this company has provided for this clinical trial.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAUTHOR\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;INFORMATION\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAUTHOR NAMES:\u0026nbsp;\u003c/strong\u003eQi You\u003csup\u003e1\u003c/sup\u003e Yang Meng\u003csup\u003e2 \u0026nbsp;\u003c/sup\u003eXiaojing Liu\u003csup\u003e3 \u0026nbsp;\u003c/sup\u003eChuanyu Sun\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eJianboWu (corresponding author)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAFFILIATIONS:\u003c/strong\u003e Department of Anesthesiology, the First Affiliated Hospital of Shandong First Medical University \u0026amp; Shandong Provincial Qianfoshan Hospital; Shandong Institute of Anesthesia and Respiratory Critical Medicine; Shandong Provincial Clinical Research Center for Anesthesiology.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCORRESPONDING AUTHOR:\u0026nbsp;\u003c/strong\u003eJianbo Wu; E-mail: [email protected]; ORCID:0000-0002-9893-9096\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAUTHOR CONTRIBUTIONS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJianbo Wu is the project leader and is responsible for the quality control of topic selection, design, experimental supervision and paper revision. Qi You is responsible for the design of the entire study and writing the paper. Chuanyu Sun, Xiaojing Liu and Meng Yang will contribute to the implementation and analysis of the program.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eETHICS DECLARATIONS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study protocol was approved by the Ethics Committee of the First Affiliated Hospital of Shandong First Medical University (Shandong Qianfoshan Hospital) (Approval No.YXLL-KY-2024(083)) on August 22, 2024.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThis clinical trial protocol received formal registration at ClinicalTrials.gov (Registration Number: NCT06711328) on November 26, 2024, prior to the enrollment of the first participant. This trial will adhere to the principles outlined in the Declaration of Helsinki, and informed written consent will be obtained from all patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003eCompeting interests\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePATIENT AND PUBLIC INVOLVEMENT\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients and/or the public were not involved in the design, conduct, reporting, or dissemination plans of this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDisclaimer:\u003c/strong\u003e The donor of the consumables has no role in the design and implementation of the study or in the decision to write and submit this manuscript\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publicationNot applicable.Competing interestsThe authors declare no competing interests.\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eConti CB, Agnesi S, Scaravaglio M, Masseria P, Dinelli ME, Oldani M, Uggeri F. Early Gastric Cancer: Update on Prevention, Diagnosis and Treatment. Int J Environ Res Public Health 2023, 20(3).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWooldrage K, Robbins EC, Duffy SW, Cross AJ. Long-term effects of once-only flexible sigmoidoscopy screening on colorectal cancer incidence and mortality: 21-year follow-up of the UK Flexible Sigmoidoscopy Screening randomised controlled trial. Lancet Gastroenterol Hepatol. 2024;9(9):811\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAtkin W, Wooldrage K, Parkin DM, Kralj-Hans I, MacRae E, Shah U, Duffy S, Cross AJ. Long term effects of once-only flexible sigmoidoscopy screening after 17 years of follow-up: the UK Flexible Sigmoidoscopy Screening randomised controlled trial. Lancet. 2017;389(10076):1299\u0026ndash;311.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi XT, Ma CQ, Qi SH, Zhang LM. Combination of propofol and dezocine to improve safety and efficacy of anesthesia for gastroscopy and colonoscopy in adults: A randomized, double-blind, controlled trial. World J Clin Cases. 2019;7(20):3237\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEarly DS, Lightdale JR, Vargo JJ 2nd, Acosta RD, Chandrasekhara V, Chathadi KV, Evans JA, Fisher DA, Fonkalsrud L, Hwang JH, et al. Guidelines for sedation and anesthesia in GI endoscopy. Gastrointest Endosc. 2018;87(2):327\u0026ndash;37.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeh JL, Shabbir A, Yuen S, So JB. Recent advances in diagnostic upper endoscopy. World J Gastroenterol. 2020;26(4):433\u0026ndash;47.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFanti L, Testoni PA. Sedation and analgesia in gastrointestinal endoscopy: what's new? 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Incidence and risk factors of nocturnal penetrations and aspirations in patients with obstructive sleep apnea during drug-induced sedation endoscopy. J Sleep Res 2024:e14314.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYin S, Hong J, Sha T, Chen Z, Guo Y, Li C, Liu Y. Efficacy and Tolerability of Sufentanil, Dexmedetomidine, or Ketamine Added to Propofol-based Sedation for Gastrointestinal Endoscopy in Elderly Patients: A Prospective, Randomized, Controlled Trial. Clin Ther. 2019;41(9):1864\u0026ndash;e18771860.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang W, Zhu C, Chen X, Tao L, He K, Wu H, Chai X, Wang S, Xia M. Comparison of the innovative endoscopic oropharyngeal airway and the conventional mouthpiece in elderly outpatients undergoing esophagogastroduodenoscopy under sedation: a prospective and randomized study. BMC Gastroenterol. 2022;22(1):8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBeitz A, Riphaus A, Meining A, Kronshage T, Geist C, Wagenpfeil S, Weber A, Jung A, Bajbouj M, Pox C, et al. Capnographic monitoring reduces the incidence of arterial oxygen desaturation and hypoxemia during propofol sedation for colonoscopy: a randomized, controlled study (ColoCap Study). Am J Gastroenterol. 2012;107(8):1205\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKlare P, Reiter J, Meining A, Wagenpfeil S, Kronshage T, Geist C, Heringlake S, Schlag C, Bajbouj M, Schneider G, et al. Capnographic monitoring of midazolam and propofol sedation during ERCP: a randomized controlled study (EndoBreath Study). Endoscopy. 2016;48(1):42\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang Y, Liu F, Zhang Y, Yang X, Wu J. The effect of capnography on the incidence of hypoxia during sedation for EGD and colonoscopy in mildly obese patients: a randomized, controlled study. BMC Anesthesiol. 2023;23(1):188.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlobal burden and strength of evidence for. 88 risk factors in 204 countries and 811 subnational locations, 1990\u0026ndash;2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet. 2024;403(10440):2162\u0026ndash;203.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCausada-Calo N, Bishay K, Albashir S, Al Mazroui A, Armstrong D. Association Between Age and Complications After Outpatient Colonoscopy. JAMA Netw Open. 2020;3(6):e208958.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeslie K, Allen ML, Hessian EC, Peyton PJ, Kasza J, Courtney A, Dhar PA, Briedis J, Lee S, Beeton AR, et al. Safety of sedation for gastrointestinal endoscopy in a group of university-affiliated hospitals: a prospective cohort study. Br J Anaesth. 2017;118(1):90\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGarc\u0026iacute;a Guzzo ME, Fernandez MS, Sanchez Novas D, Salgado SS, Terrasa SA, Domenech G, Teijido CA. Deep sedation using propofol target-controlled infusion for gastrointestinal endoscopic procedures: a retrospective cohort study. BMC Anesthesiol. 2020;20(1):195.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarends CRM, Driesens MK, van Amsterdam K, Struys M, Absalom AR. Moderate-to-Deep Sedation Using Target-Controlled Infusions of Propofol and Remifentanil: Adverse Events and Risk Factors: A Retrospective Cohort Study of 2937 Procedures. Anesth Analg. 2020;131(4):1173\u0026ndash;83.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVargo JJ. 2nd: Sedation-related complications in gastrointestinal endoscopy. Gastrointest Endosc Clin N Am. 2015;25(1):147\u0026ndash;58.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLahav Y, Rosenzweig E, Heyman Z, Doljansky J, Green A, Dagan Y. Tongue base ultrasound: a diagnostic tool for predicting obstructive sleep apnea. Ann Otol Rhinol Laryngol. 2009;118(3):179\u0026ndash;84.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStoohs RA, Knaack L, Blum HC, Janicki J, Hohenhorst W. Differences in clinical features of upper airway resistance syndrome, primary snoring, and obstructive sleep apnea/hypopnea syndrome. Sleep Med. 2008;9(2):121\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLoube DI, Andrada TF. Comparison of respiratory polysomnographic parameters in matched cohorts of upper airway resistance and obstructive sleep apnea syndrome patients. Chest. 1999;115(6):1519\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMartin SE, Mathur R, Marshall I, Douglas NJ. The effect of age, sex, obesity and posture on upper airway size. Eur Respir J. 1997;10(9):2087\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"elderly patients, endoscopy oropharyngeal airway, gastroenteroscopy","lastPublishedDoi":"10.21203/rs.3.rs-6094966/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6094966/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e Respiratory depression and airway obstruction are the most common respiratory adverse reactions in elderly patients undergoing gastroenteroscopy under sedation. Additionally, sharing the airway with endoscopists can complicate airway management. Here, we apply COMBO endoscopy oropharyngeal airway, a novel airway management device with integrated capnography monitoring and dual oxygenation support,to investigate the incidence of adverse events such as hypoxemia and airway obstruction in elderly patients during anaesthesia, providing a reference for airway management in clinical practice.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods and findings \u003c/strong\u003eThis will be a prospective, randomised, controlled clinical study. We will enrol 164 elderly patients (65 to ≤80 years old) scheduled for painless gastroenteroscopy. The participants will be randomly assigned to two groups. The experimental group will use an oropharyngeal airway designed for gastroscopy. The control group will receive an ordinary endoscopic bite block. The primary outcome measure will be the incidence of hypoxia (75% ≤ SpO2 \u0026lt; 90%, ≤60 s), and the secondary outcome measures will be the incidence of severe hypoxia (SpO2 \u0026lt; 75% or 75% ≤SpO2 \u0026lt; 90%, ≥60 seconds); incidence of circulatory fluctuations [severe bradycardia (\u0026lt; 50 beats/min), a mean arterial pressure (MAP) fluctuation greater than 30% of the baseline value or an MAP \u0026lt; 60 mmHg]; incidence of airway intervention; dose of additional drugs administered during the procedure; endoscopist satisfaction;and incidence of various adverse events.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults \u003c/strong\u003eThis clinical studyaims to evaluate whether an oropharyngeal airway dedicated to gastroscopy can effectively maintain airway patency and alleviate retrolingual collapse, thereby preventing hypoxemia. It also aims to determine whether it can reduce the incidence of respiratory-related adverse events.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTrial Registration \u003c/strong\u003eThis clinical trial protocol received formal registration at ClinicalTrials.gov (Registration Number: NCT06711328) on November 26, 2024.\u003c/p\u003e","manuscriptTitle":"Clinical Efficacy of COMBO endoscopy oropharyngeal airway in Elderly Patients Undergoing Painless Gastroenteroscopy Under Anesthesia: A Randomized Controlled Trial Protocol","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-06 14:10:27","doi":"10.21203/rs.3.rs-6094966/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-05T06:02:21+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-02T10:23:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"180587170332839588641944006782516036976","date":"2025-05-27T01:47:18+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-15T14:50:59+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"232050499097319466028647684035454928073","date":"2025-04-27T05:02:47+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-15T02:36:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-04T08:16:39+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-04T08:16:38+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Anesthesiology","date":"2025-02-24T08:41:41+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-anesthesiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bane","sideBox":"Learn more about [BMC Anesthesiology](http://bmcanesthesiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bane","title":"BMC Anesthesiology","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a157312e-7f24-4f10-a91b-a8003b44b9f0","owner":[],"postedDate":"May 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-09-29T16:01:56+00:00","versionOfRecord":{"articleIdentity":"rs-6094966","link":"https://doi.org/10.1186/s12871-025-03311-8","journal":{"identity":"bmc-anesthesiology","isVorOnly":false,"title":"BMC Anesthesiology"},"publishedOn":"2025-09-26 15:58:08","publishedOnDateReadable":"September 26th, 2025"},"versionCreatedAt":"2025-05-06 14:10:27","video":"","vorDoi":"10.1186/s12871-025-03311-8","vorDoiUrl":"https://doi.org/10.1186/s12871-025-03311-8","workflowStages":[]},"version":"v1","identity":"rs-6094966","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6094966","identity":"rs-6094966","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}