THRIVE in Sedated Gastrointestinal Endoscopy

THRIVE Versus Standard Nasal Cannula for Oxygenation, Oxygen Reserve Index, and Hypoxemia During Sedated Gastrointestinal Endoscopy

This prospective observational study aims to evaluate the effectiveness of Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) compared to standard nasal cannula (SNC) oxygen supplementation in patients undergoing elective diagnostic gastroscopy under propofol sedation. The primary outcome is the incidence of hypoxemia (SpO₂ <93% for ≥20 seconds) during the procedure. Secondary outcomes include the need for airway intervention, Oxygen Reserve Index (ORi) values, peripheral oxygen saturation (SpO₂) levels, and hemodynamic parameters recorded throughout the procedure. Oxygen delivery method was selected by the attending anesthesia provider independent of the study team.

Study Overview

• Status: Completed
• Conditions: Gastrointestinal Endoscopy; Hypoxemia
• Intervention / Treatment: Device: High-Flow Nasal Oxygen (THRIVE); Device: Standard Nasal Cannula Oxygen

Detailed Description

Procedural sedation for gastrointestinal endoscopy is associated with risks of respiratory depression, airway obstruction, and hypoxemia due to the pharmacological effects of sedative agents. Standard nasal cannula (SNC) oxygen supplementation, while widely used, is limited in its ability to guarantee adequate inspired oxygen concentrations, particularly during apneic episodes.

THRIVE (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange) delivers heated and humidified oxygen at flow rates up to 70 L/min via a non-invasive nasal cannula. The high-flow system generates positive nasopharyngeal pressure, reduces anatomical dead space through a washout effect, increases end-expiratory lung volume, and extends safe apnea time by delaying arterial desaturation. These physiological mechanisms may offer significant advantages over standard low-flow oxygen delivery during sedated endoscopy.

In this single-center prospective observational study, adult patients (age ≥18, ASA I-III, BMI <35 kg/m²) undergoing elective diagnostic gastroscopy under propofol sedation were monitored with continuous SpO₂, ETCO₂, BIS, and non-invasive Oxygen Reserve Index (ORi) monitoring. Supplemental oxygen was provided either via THRIVE at 30 L/min or standard nasal cannula at 10 L/min, based on the attending anesthesiologist's preference. Preoxygenation was initiated 2 minutes before induction and continued until procedure completion. Sedation was maintained with propofol 1-1.5 mg/kg targeting BIS 60-80; fentanyl 0.5-1 mcg/kg was administered when required. Hemodynamic and respiratory parameters were recorded at baseline, pre-induction, post-induction, intraoperatively, and at procedure end. Airway interventions were standardized and applied when apnea lasted ≥20 seconds or SpO₂ dropped ≤93% for ≥20 seconds.

• Study Type: Observational
• Enrollment (Actual): 222

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • Istanbul Provincial Health Directorate Fatih Sultan Mehmet Training and Research Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients aged 18 years and older with ASA physical status I-III and BMI <35 kg/m², scheduled for elective diagnostic gastroscopy under propofol sedation at a single tertiary care center. Patients with severe cardiopulmonary disease, pregnancy, prior facial or oropharyngeal surgery, baseline hypoxemia, hemoglobinopathy, or significant anemia were excluded. Supplemental oxygen delivery method (THRIVE vs. standard nasal cannula) was determined by the anesthesia provider independently of the study team.

Description

Inclusion Criteria:

• Age ≥18 years
• ASA physical status I-III
• Body mass index (BMI) <35 kg/m²
• Scheduled for elective diagnostic gastroscopy under propofol sedation
• Baseline SpO₂ >93% on room air prior to the procedure
• Hemoglobin level ≥10.0 g/dL prior to the procedure
• Willing and able to provide written informed consent

Exclusion Criteria:

• Severe chronic pulmonary disease (e.g., COPD, interstitial lung disease)
• Severe chronic cardiac disease
• BMI ≥35 kg/m²
• Pregnancy
• History of facial or oropharyngeal surgery
• Baseline SpO₂ ≤93% on room air prior to the procedure
• Hemoglobinopathy
• Hemoglobin level <10.0 g/dL prior to the procedure

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
THRIVE Group (High-Flow Nasal Oxygen); Adult patients (age ≥18, ASA I-III, BMI <35 kg/m²) undergoing elective diagnostic gastroscopy under propofol sedation. Supplemental oxygen was provided via a high-flow nasal oxygen system (THRIVE) at 30 L/min, initiated 2 minutes before induction and continued throughout the procedure. Sedation was maintained with propofol 1-1.5 mg/kg targeting BIS 60-80. Fentanyl 0.5-1 mcg/kg was administered if needed. Monitoring included SpO₂, ETCO₂, BIS, and Oxygen Reserve Index (ORi). Primary outcome: incidence of hypoxemia (SpO₂ <93% for ≥20 seconds). Secondary outcomes: need for airway intervention, supplemental oxygen escalation, and ORi/SpO₂ values throughout the procedure.	Device: High-Flow Nasal Oxygen (THRIVE); Heated and humidified high-flow nasal oxygen was delivered via a THRIVE (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange) system at a flow rate of 30 L/min with FiO₂ of 1.0, initiated 2 minutes prior to propofol induction and maintained continuously until the end of the procedure. The system generates nasopharyngeal positive pressure and reduces dead space, thereby supporting oxygenation and delaying desaturation during apneic episodes.; Other Names: HFNO
SNC Group (Standard Nasal Cannula); Adult patients (age ≥18, ASA I-III, BMI <35 kg/m²) undergoing elective diagnostic gastroscopy under propofol sedation. Supplemental oxygen was provided via standard nasal cannula at 10 L/min, initiated 2 minutes before induction and continued throughout the procedure. Sedation was maintained with propofol 1-1.5 mg/kg targeting BIS 60-80. Fentanyl 0.5-1 mcg/kg was administered if needed. Monitoring included SpO₂, ETCO₂, BIS, and Oxygen Reserve Index (ORi). Primary outcome: incidence of hypoxemia (SpO₂ <93% for ≥20 seconds). Secondary outcomes: need for airway intervention, supplemental oxygen escalation, and ORi/SpO₂ values throughout the procedure.	Device: Standard Nasal Cannula Oxygen; Supplemental oxygen was administered via a standard nasal cannula at a flow rate of 10 L/min, initiated 2 minutes prior to propofol induction and maintained continuously until the end of the procedure. This represents the standard of care for oxygen supplementation during procedural sedation for gastrointestinal endoscopy.; Other Names: SNC

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of Hypoxemia During Procedural Sedation	Hypoxemia was defined as peripheral oxygen saturation (SpO₂) falling below 93% for a duration of ≥20 seconds, as measured by continuous pulse oximetry. The proportion of patients experiencing at least one hypoxemic episode was compared between the THRIVE and standard nasal cannula groups.	From induction of sedation until end of the endoscopic procedure (estimated 10-30 minutes)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Need for Airway Intervention Due to Hypoxemia or Apnea	Proportion of patients requiring any of the following interventions during the procedure: jaw thrust or head extension maneuver, escalation of supplemental oxygen flow, or mask ventilation with 100% oxygen continued until SpO₂ ≥98%. Interventions were triggered by apnea (absence of respiratory activity or loss of ETCO₂ tracing for >20 seconds) or SpO₂ ≤93% for ≥20 seconds.	From induction of sedation until end of the endoscopic procedure (estimated 10-30 minutes)
Oxygen Reserve Index (ORi) Throughout the Procedure	ORi was continuously monitored using a non-invasive multiwavelength pulse co-oximetry sensor. Values were recorded at baseline, pre-induction, post-induction, during the procedure, and at procedure end. ORi reflects oxygen reserve in the moderate hyperoxic range (PaO₂ 100-200 mmHg) and was compared between groups at each time point.	Baseline, pre-induction, post-induction, intraoperative, and immediately after procedure completion
Peripheral Oxygen Saturation (SpO₂) Throughout the Procedure	SpO₂ was continuously monitored via pulse oximetry and recorded at baseline, pre-induction, post-induction, during the procedure, and at procedure end. Mean SpO₂ values and the number and duration of desaturation episodes were compared between the THRIVE and standard nasal cannula groups.	Baseline, pre-induction, post-induction, intraoperative, and immediately after procedure completion
Intraoperative Hemodynamic Stability	Mean arterial pressure (MAP) and heart rate (HR) were recorded at baseline, pre-induction, post-induction, during the procedure, and at procedure end. Hypotension was defined as MAP ≥25% below baseline; hypertension as ≥20% increase in systolic blood pressure from baseline; bradycardia as HR <60 bpm. The incidence of each event was compared between groups.	Baseline, pre-induction, post-induction, intraoperative, and immediately after procedure completion

Collaborators and Investigators

• Sponsor: Fatih Sultan Mehmet Training and Research Hospital
• Investigators: Principal Investigator: oznur demiroluk, MD, fatih sultan mehmet research and training hospital

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2025
• Primary Completion (Actual): October 1, 2025
• Study Completion (Actual): October 1, 2025

Study Registration Dates

• First Submitted: March 16, 2026
• First Submitted That Met QC Criteria: March 17, 2026
• First Posted (Actual): March 23, 2026

Study Record Updates

• Last Update Posted (Actual): March 23, 2026
• Last Update Submitted That Met QC Criteria: March 17, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: THRIVE; Gastroscopy; Oxygen Reserve Index; Procedural Sedation; High-Flow Nasal Oxygen; Sedation-related Hypoxemia; Endoscopy Sedation
• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hypoxia; Therapeutics; Tobacco Use Cessation Devices
• Other Study ID Numbers: THRIVE-FSM

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: No formal data sharing plan has been established at this time. Individual participant data sharing will be considered upon reasonable request, subject to ethical approval and institutional regulations.

Drug and device information, study documents

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