Comparison of the Efficacy of Nasal Mask and Nasal Cannula Oxygenation During Gastrointestinal Endoscopic Procedures Performed Under Target-Controlled Propofol Infusion Anesthesia With Brain Function Monitoring (SedLine): A Randomized Controlled Trial
Phase: NA
Conditions: Hypoxemia, Conscious Sedation
Sponsor: Sultan Abdulhamid Han Training and Research Hospital, Istanbul, Turkey

 
STUDY PROTOCOL AND STATISTICAL ANALYSIS PLAN (SAP) 
Comparison of the Efficacy of Nasal Mask and Nasal Cannula Oxygenation During 
Gastrointestinal Endoscopic Procedures Performed Under Target-Controlled 
Propofol Infusion Anesthesia With SedLine Brain Function Monitoring: A 
Randomized Controlled Trial 
 
Impact of Nasal Mask Versus Nasal Cannula Oxygenation on Hypoxemia in 
Gastrointestinal Endoscopy: A SedLine-Guided Randomized Controlled Trial 
 
NCT ID: Not yet assigned (pending) 
Unique Protocol ID: 2024/392 
Secondary ID / Other Identifier: 2024/392 
Issuing Organization: SBÜ Sancaktepe Şehit Prof. Dr. İlhan Varank Training and 
Research Hospital Scientific Research Ethics Committee 
Facility: University of Health Sciences Sultan Abdulhamid Han Training and Research 
Hospital, Istanbul, Turkey 
Ethics approval: Approval No. 2024/392 (December 26, 2024) 
Study Start Date: January 06, 2025 (Actual) 
Primary Completion Date: August 26, 2025 (Actual) 
Study Completion Date: November 15, 2025 (Actual) 
Overall Recruitment Status: Completed 
Enrollment: 600 participants (Actual) 
Document Date: December 15, 2025 
 
 

Table of Contents 
Note: Update this section after final formatting (Word can auto-generate a TOC). 
 
 

1. Study Synopsis 
Design: Prospective, randomized, parallel-group, open-label controlled trial. 
Population: Adults (18–75 years), ASA physical status I–III, scheduled for gastroscopy 
and colonoscopy in the same session. 
Interventions: Oxygen at 4 L/min via a nasal mask versus standard nasal cannula during 
target-controlled propofol sedation. 
Sedation monitoring: SedLine® brain function monitoring with Patient State Index (PSI) 
targeted between 50 and 80. 
Primary outcome: Hypoxemia incidence (SpO₂ ≤ 90%). 
Sample size: 600 participants (300 per group). 
2. Background and Rationale 
Hypoxemia is a common and clinically important adverse event during propofol-sedated 
gastrointestinal endoscopy. Standard nasal cannula oxygen supplementation may be 
insufficient in some patients. A nasal mask can improve oxygen delivery and potentially 
reduce hypoxemia and airway interventions. This trial evaluates whether a nasal mask 
reduces hypoxemia compared with a standard nasal cannula under a standardized, 
SedLine-guided, target-controlled infusion (TCI) propofol sedation protocol. 
3. Objectives 
Primary objective: To compare the incidence of hypoxemia (SpO₂ ≤ 90%) between the 
nasal mask and nasal cannula groups during the procedure. 
Secondary objectives: To compare severe hypoxemia, hypoxemia duration, minimum 
SpO₂, need for airway interventions, procedure time, recovery time, adverse events, and 
clinician satisfaction scores. 
4. Study Design 
This is a single-center, interventional, randomized (1:1), parallel-assignment trial. 
Blinding was not feasible due to the visible oxygen delivery device. 
5. Study Population 
5.1 Inclusion Criteria 
 Age 18–75 years 
 ASA physical status I–III 
 Scheduled to undergo both gastroscopy and colonoscopy in the same session 
 Planned intravenous propofol sedation for the procedure 

5.2 Exclusion Criteria 
 Myocardial infarction within 6 months or unstable angina history 
 Severe arrhythmia history 
 Acute pharyngitis, tonsillitis, or pneumonia 
 Baseline room air SpO₂ ≤ 90% 
 Severe cardiopulmonary disease or anticipated difficult airway 
 Severe obstructive sleep apnea syndrome 
 Known allergy to propofol, egg, soy, albumin, lidocaine, or similar agents 
 Pregnancy or lactation 
 Participation in another clinical study within the previous 3 months 
 Inability to provide informed consent 
6. Randomization and Allocation 
Participants were randomized 1:1 to nasal mask versus nasal cannula oxygenation using a 
pre-prepared randomization list. Allocation was implemented using opaque, sealed 
envelopes. 
7. Interventions and Procedures 
7.1 Oxygenation 
Nasal mask arm: Oxygen at 4 L/min delivered via a nasal mask covering the nasal area. 
Nasal cannula arm: Oxygen at 4 L/min delivered via a standard adult nasal cannula. 
7.2 Sedation Protocol 
All participants received propofol sedation using a target-controlled infusion system. 
Sedation was titrated to maintain SedLine PSI values between 50 and 80. Standard 
monitoring included noninvasive blood pressure, ECG, heart rate, and peripheral oxygen 
saturation (SpO₂). 
8. Outcome Measures 
8.1 Primary Outcome 
Incidence of hypoxemia during the procedure, defined as any occurrence of SpO₂ ≤ 90%. 
8.2 Secondary Outcomes 
 Severe hypoxemia: SpO₂ ≤ 75% or SpO₂ ≤ 90% for >60 seconds 
 Duration of hypoxemia (seconds) 
 Minimum SpO₂ during the procedure 
 Need for airway interventions 
 Adverse events 

 Procedure time and recovery time 
 Clinician satisfaction scores (0–100) 
9. Statistical Analysis Plan 
All analyses were performed in the intention-to-treat population using IBM SPSS 
Statistics (version 26.0). Sample size calculations were performed using PASS (version 
11.0). Two sided p < 0.05 was considered statistically significant unless otherwise 
specified. 
Normality was assessed using the Shapiro–Wilk test. Continuous variables were 
compared using the independent samples t test or Mann–Whitney U test, as appropriate, 
and are reported as mean ± standard deviation or median [interquartile range]. Hodges–
Lehmann median differences with 95% confidence intervals were calculated for selected 
non normally distributed continuous outcomes. Categorical variables were compared 
using chi square or Fisher’s exact tests, and key binary outcomes were reported with 
relative risk and odds ratio with 95% confidence intervals. 
Baseline balance was assessed using absolute standardized difference (|ASD| < 0.10). 
Spearman correlation was used for associations between continuous variables. PSI was 
defined as the mean between 5 and 20 minutes after induction (PSI 5–20). Exploratory 
minute based logistic regression at 5, 10, 15, and 20 minutes used Bonferroni correction 
(p < 0.0125). Subgroup analyses (age, sex, BMI, ASA) used treatment-by-subgroup 
interaction terms (Wald test) with Bonferroni corrected threshold p < 0.0125 for 
interaction testing. Multivariable logistic regression was used to identify predictors of 
hypoxemia. 
10. Ethics and Dissemination 
The study was approved by the local ethics committee and conducted in accordance with 
the Declaration of Helsinki. Written informed consent was obtained from all participants. 
11. Version History 
Version: 1.0 
Date: December 15, 2025 
Summary of changes: Initial version prepared for ClinicalTrials.gov PRS Study 
Documents upload.