HFNO Versus Face Mask for Cerebral Oxygenation During Procedural Sedation

Effects of High-Flow Nasal Oxygen Versus Conventional Face Mask Oxygen on Cerebral Oxygenation During Out-of-Operating-Room Procedural Sedation: A Prospective Randomized Controlled Trial

This prospective randomized controlled trial aims to compare the effects of high-flow nasal oxygen (HFNO) and conventional face mask oxygen therapy on cerebral oxygenation during procedural sedation performed outside the operating room. Adult patients undergoing elective diagnostic or interventional procedures under procedural sedation will be randomly assigned to receive either HFNO or conventional face mask oxygen. Regional cerebral oxygen saturation will be continuously monitored using near-infrared spectroscopy (NIRS), while sedation depth will be assessed using the Patient State Index (PSI, SedLine) and the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scale. Secondary outcomes include peripheral oxygenation, ventilation parameters, arterial blood gas values, airway interventions, hemodynamic variables, and patient and practitioner satisfaction.

Study Overview

• Status: Recruiting
• Conditions: Hypoxemia; Cerebral Oxygenation; Procedural Sedation; SEDLine
• Intervention / Treatment: Device: High-Flow Nasal Oxygen (HFNO); Device: Conventional Face Mask Oxygen

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ahmet Aksu, Assistant Professor; Phone Number: +905303493896; Email: drahmetaksu@gmail.com

Study Locations

• Turkey (Türkiye)
  • Elâzığ
    • Elâzığ, Elâzığ, Turkey (Türkiye), 23100
      • Recruiting
      • Fırat University Faculty of Medicine Hospital
      • Contact: Ahmet Aksu, Assistant Professor; Phone Number: +904242333555 +905303493896; Email: drahmetaksu@gmail.com
      • Contact: Ahmet Demirdağ, Assistant Professor; Phone Number: +905427158774; Email: a.demirdag@firat.edu.tr
      • Sub-Investigator: Ahmet Demirdağ, Assistant Professor

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age 18 years or older
• American Society of Anesthesiologists physical status I-IV
• Scheduled for an elective diagnostic or interventional procedure performed under procedural sedation in a non-operating-room setting
• Ability to provide written informed consent
• Willingness to participate in the study

Exclusion Criteria:

• Age younger than 18 years
• Refusal or inability to provide written informed consent
• Known neurological disorders
• History of ischemic or hemorrhagic stroke
• History of traumatic brain injury or previous cranial surgery
• Peripheral arterial disease or systemic vasculitis
• Advanced heart failure
• Uncontrolled hypertension
• Uncontrolled diabetes mellitus
• Advanced chronic obstructive pulmonary disease (COPD)
• Severe anemia (hemoglobin <8 g/dL)
• Skin lesions or other conditions preventing proper placement of NIRS sensors
• Nasal deformity or nasal obstruction preventing the use of high-flow nasal oxygen therapy
• Any condition that, in the opinion of the investigators, could interfere with study participation or the interpretation of study results

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High-Flow Nasal Oxygen (HFNO); Participants receive heated humidified high-flow nasal oxygen during procedural sedation.	Device: High-Flow Nasal Oxygen (HFNO); Participants receive heated humidified high-flow nasal oxygen during procedural sedation.
Active Comparator: Conventional Face Mask Oxygen; Participants receive conventional face mask oxygen therapy during procedural sedation.	Device: Conventional Face Mask Oxygen; Oxygen administered through a conventional face mask at 6 L/min with an approximate FiO₂ of 40%.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Regional Cerebral Oxygen Saturation (ΔrSO₂)	The change in regional cerebral oxygen saturation (rSO₂) measured by near-infrared spectroscopy (NIRS), calculated as the difference between the mean intra-procedural rSO₂ and the baseline value.	From initiation of procedural sedation until completion of the procedure (up to approximately 120 minutes).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peripheral Oxygen Saturation (SpO₂)		From baseline to completion of procedural sedation (up to approximately 120 minutes).
End-Tidal Carbon Dioxide (EtCO₂)		Baseline and at completion of the procedure.
Arterial Oxygen Tension (PaO₂)		Before sedation and immediately after completion of the procedure.
Arterial Carbon Dioxide Tension (PaCO₂)		Before sedation and immediately after completion of the procedure.
Incidence of Hypoxemia	Peripheral oxygen saturation <90% lasting at least 10 seconds.	During procedural sedation (up to approximately 120 minutes).
Number of Participants with a ≥20% Decrease in Regional Cerebral Oxygen Saturation (rSO₂) from Baseline	Number of participants who experience a decrease in regional cerebral oxygen saturation (rSO₂) of 20% or more from the baseline value during procedural sedation.	During procedural sedation (up to approximately 120 minutes).
Number of Participants Requiring Airway Intervention During Procedural Sedation	Number of participants requiring any airway intervention, including chin lift, jaw thrust, mask ventilation, supraglottic airway placement, or endotracheal intubation during procedural sedation.	During procedural sedation.
Patient State Index (PSI) During Procedural Sedation	Mean Patient State Index (PSI) recorded throughout procedural sedation. The PSI ranges from 0 to 100, with lower values indicating deeper levels of sedation.	Throughout procedural sedation until completion of the procedure.
Modified Observer's Assessment of Alertness/Sedation (MOAA/S) Score During Procedural Sedation	Mean Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score recorded during procedural sedation. Scores range from 0 to 5, where lower scores indicate deeper sedation and higher scores indicate greater alertness.	Throughout procedural sedation until completion of the procedure.
Heart Rate During Procedural Sedation	Mean heart rate (beats per minute) recorded from baseline until completion of the procedure.	From baseline until completion of the procedure.
Mean Arterial Pressure During Procedural Sedation	Mean non-invasive arterial blood pressure (mmHg) recorded from baseline until completion of the procedure.	Throughout procedural sedation until completion of the procedure.
Sedative Drug Consumption	Total doses of propofol, remifentanil, and midazolam.	During procedural sedation.
Patient Satisfaction Score Using a 5-Point Likert Scale	Patient satisfaction was assessed immediately after recovery using a 5-point Likert scale (1 = very dissatisfied, 5 = very satisfied). Higher scores indicate greater satisfaction.	Immediately after recovery from procedural sedation.
Practitioner Satisfaction Score Using a 5-Point Likert Scale	Practitioner satisfaction with the procedure was assessed immediately after completion using a 5-point Likert scale (1 = very dissatisfied, 5 = very satisfied). Higher scores indicate greater satisfaction.	Immediately after completion of the procedure.

Collaborators and Investigators

• Sponsor: Firat University

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2026
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: July 13, 2026
• First Submitted That Met QC Criteria: July 16, 2026
• First Posted (Actual): July 21, 2026

Study Record Updates

• Last Update Posted (Actual): July 21, 2026
• Last Update Submitted That Met QC Criteria: July 16, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Cerebral oxygenation; Procedural sedation; Near-infrared spectroscopy (NIRS); High-flow nasal oxygen (HFNO); Patient State Index (PSI)
• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Hypoxia
• Other Study ID Numbers: 47670

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared because the study was not designed with a data-sharing plan, and participant-level data contain potentially identifiable information.

Drug and device information, study documents

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