Noninvasive Technique and High Flow Nasal Oxygen in Respiratory Failure

Different Modalities of Combined Noninvasive Ventilation With High Flow Nasal Oxygen Versus Noninvasive Ventilation Alone in Acute Respiratory Failure

After obtaining Institutional Ethical Committee approval of Faculty of Medicine, Minia University and written informed consent from patients or first- degree relatives, this prospective randomized non-blind comparative study will be conducted in adult intensive care unit (ICU) of Anesthesia, Intensive Care and Pain management department Minia university hospital over a period from September 2025 to April 2026. This study is designed to compare the effectiveness of two protocols of sequential use of High Flow Nasal Cannula (HFNC) and noninvasive ventilation (NIV) versus NIV alone in patients with Acute Respiratory failure (ARF) admitted to the intensive care unit (ICU). The study will include 75 patients of both sexes, classified as ASA class Ⅰ-ⅠⅠⅠ, divided into three groups with 25 patients in each group.

Study Overview

• Status: Recruiting
• Conditions: Respiratory Failure
• Intervention / Treatment: Device: HFNC; Device: NIV

Detailed Description

After failure of a trial of treatment with conventional oxygen therapy delivered through a face mask, with a FiO2 at least of 50% for 15 minutes, patients will be assigned into one of three groups:

• Group A: will receive first HFNC for 2 hours alternating with NIV for

  1 hour. This alternating cycle of HFNC and NIV will be repeated for a total of 16 hours of HFNC and 8 hours of NIV for the first 24 hours.

• Group B: will receive first HFNC for 3 hours alternating with NIV for 3 hours. This alternating cycle of HFNC and NIV will be repeated for a total of 12 hours of HFNC and 12 hours of NIV for the first 24 hours.
• Group C (The control group): will receive conventional oxygen therapy and NIV as required for acute respiratory failure. Randomization will be performed using a computer-generated randomization sequence. HFNC therapy will be administered using the Vapotherm system (Vapotherm, INC. 100 Domain Drive. Exeter, NH 03833. Made In U.S.A.). This system allows for precise control of the fraction of inspired oxygen (FiO₂) and the delivery of heated, humidified gas via large-bore bi-nasal prongs. The initial flow rate will be set to 50 L/min with an FiO₂ of 0.5, and adjustments will be made to maintain SpO₂ ≥ 92%. If the initial settings are poorly tolerated by the patient, the flow rate and FiO₂ will be titrated to the maximum tolerated level, with a minimum flow rate of 30 L/min. Blood gas analysis will be performed within one hour of initiating HFNC to assess oxygenation, PaCO₂ and acid-base status. Continuous monitoring will be conducted throughout the session to ensure patient comfort and optimize therapeutic efficacy. NIV will be administered via a full-face mask connected to an ICU ventilator (TECME Corporation. Made In U.S.A. or Airliquide Medical Extend XT. Made In France.) equipped with a dedicated NIV mode and a heated humidifier (MR850, Fisher & Paykel Healthcare), while patient positioned in a semi-recumbent position. The ventilator will be set to a pressure support level to achieve an expired tidal volume of 6-8 mL/kg of ideal body weight, with a target respiratory rate of < 30 breaths per minute. FiO₂ will be adjusted to maintain SpO₂ at 92%, and PEEP will be set at least 4 cm H₂O. All patients will be continuously monitored for respiratory rate, heart rate, blood pressure, and SpO₂ throughout the study. Blood gas analysis will be conducted within one hour after the initiation of HFNC and NIV to assess oxygenation, ventilation, and acid-base status. If improvement in respiratory distress occurs, the noninvasive strategy will be stopped. Also, The study will be discontinued and invasive mechanical ventilation will be initiated if any of the following criteria are recorded: evident worsening of respiratory distress, breathing frequency of ≥ 40 breaths/min, abundant secretions, SpO₂ remaining below 92% despite an FIO₂ of 1.0, or pH ≤ 7.35, Glasgow Coma Scale score < 8/15 or psychomotor agitation hindering nursing care, bradycardia (heart rate < 50 bpm), tachyarrhythmia (heart rate > 150 bpm), persistent hypotension (defined by systolic blood pressure < 90 mmHg or mean arterial blood pressure < 65 mm Hg, despite fluid resuscitation or need for vasopressors), respiratory or cardiopulmonary arrest

• Study Type: Interventional
• Enrollment (Estimated): 75
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Omyma S Mohamed, Prof.; Phone Number: 0106 1762894; Email: Omaima.Shehata@mu.edu.eg
• Study Contact Backup: Name: Shadwa R Mohamed, Ass. Prof.; Phone Number: +20 100 415 7778; Email: Shadwa.Rabie@mu.edu.eg

Study Locations

• Egypt
  • Minya Governorate
    • Minya, Minya Governorate, Egypt
      • Recruiting
      • Minya university hospitals
      • Contact: Ahmad E Mahran, Professor; Phone Number: +201060027399; Email: ahmed_ezz@mu.edu.eg

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age ≥18 year of both sexes. • Diagnosed with Acute Respiratory Failure (ARF) defined as the combination of a PaO2/FiO2 ratio < 300 after 15 minutes of conventional oxygen delivered through a face mask, with a FiO2 at least of 50% and respiratory rate > 30 breaths/min.

Exclusion Criteria:

• Chronic respiratory disease

  • Cardiogenic pulmonary edema
  • Life-threatening arrythmias
  • Hemodynamic instability requiring vasopressors
  • Facial abnormalities preventing NIV or HFNC application
  • Glasgow coma score of ≤ 12 points (Teasdale et al. 1974)
  • Agitated patients characterized by RASS score (Richmond Agitation Sedation Scale) ≥ +2
  • Patients who needed immediate endotracheal intubation
  • Pregnant patients

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: HFNC and NIV 2:1; This group will receive first HFNC for 2 hours alternating with NIV for 1 hour. This alternating cycle of HFNC and NIV will be repeated for a total of 16 hours of HFNC and 8 hours of NIV for the first 24 hours	Device: HFNC; High-flow nasal cannula (HFNC) is a valuable alternative for delivering oxygen therapy in patients with acute respiratory failure. It delivers heated and humidified oxygen at high flow rates-up to 60 L/min-through nasal prongs, allowing for better matching of inspiratory flow, a degree of positive airway pressure, and washout of nasopharyngeal dead space. These features contribute to improved oxygenation and reduced respiratory rate. Additionally, HFNC offers superior comfort and ease of communication compared to traditional masks, which may enhance patient compliance. Importantly, recent evidence suggests that HFNC can also assist in mild hypercapnic conditions by reducing the work of breathing and improving CO₂ clearance in selected patients; Device: NIV; Noninvasive ventilation (NIV) delivers positive airway pressure either continuously or in a bilevel mode to support ventilation and oxygenation. It has been widely used in managing conditions such as COPD exacerbations, cardiogenic pulmonary edema, and moderate forms of ARDS. NIV enhances alveolar ventilation, unloads respiratory muscles, and improves gas exchange while reducing the need for intubation in many cases. However, its effectiveness depends on proper patient selection and interface tolerance, and it may be less beneficial in patients with excessive secretions, altered mental status, or hemodynamic instability
Experimental: HFNC and NIV 3:3; This group will receive first HFNC for 3 hours alternating with NIV for 3 hours. This alternating cycle of HFNC and NIV will be repeated for a total of 12 hours of HFNC and 12 hours of NIV for the first 24 hours	Device: HFNC; High-flow nasal cannula (HFNC) is a valuable alternative for delivering oxygen therapy in patients with acute respiratory failure. It delivers heated and humidified oxygen at high flow rates-up to 60 L/min-through nasal prongs, allowing for better matching of inspiratory flow, a degree of positive airway pressure, and washout of nasopharyngeal dead space. These features contribute to improved oxygenation and reduced respiratory rate. Additionally, HFNC offers superior comfort and ease of communication compared to traditional masks, which may enhance patient compliance. Importantly, recent evidence suggests that HFNC can also assist in mild hypercapnic conditions by reducing the work of breathing and improving CO₂ clearance in selected patients; Device: NIV; Noninvasive ventilation (NIV) delivers positive airway pressure either continuously or in a bilevel mode to support ventilation and oxygenation. It has been widely used in managing conditions such as COPD exacerbations, cardiogenic pulmonary edema, and moderate forms of ARDS. NIV enhances alveolar ventilation, unloads respiratory muscles, and improves gas exchange while reducing the need for intubation in many cases. However, its effectiveness depends on proper patient selection and interface tolerance, and it may be less beneficial in patients with excessive secretions, altered mental status, or hemodynamic instability
Experimental: NIV only; This group will receive conventional oxygen therapy and NIV as required for acute respiratory failure	Device: NIV; Noninvasive ventilation (NIV) delivers positive airway pressure either continuously or in a bilevel mode to support ventilation and oxygenation. It has been widely used in managing conditions such as COPD exacerbations, cardiogenic pulmonary edema, and moderate forms of ARDS. NIV enhances alveolar ventilation, unloads respiratory muscles, and improves gas exchange while reducing the need for intubation in many cases. However, its effectiveness depends on proper patient selection and interface tolerance, and it may be less beneficial in patients with excessive secretions, altered mental status, or hemodynamic instability

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The changes in PaO₂/FiO₂ ratio (the ratio of arterial oxygen partial pressure expressed in mmHg and the fraction of inspired oxygen expressed as a decimal)	The primary endpoint is the changes in PaO₂/FiO₂ ratio (the ratio of arterial oxygen partial pressure expressed in mmHg and the fraction of inspired oxygen expressed as a decimal) from baseline to 24 hours.	From baseline and thoughout the first 24 hours of the start of the technique

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in the arterial blood gases values: PH level, PaCO₂	Changes in the arterial blood gases values: PH level, PaCO₂ from baseline to 6, 12, 18 and 24h.	From baseline to 6th hour, 12th hour, 18th hour and 24th hour of the first day of the start of the technique.
Respiratory rate	Respiratory rate	At the baseline then at 6th hour, 12th hour, 18th hour and 24th hour of the first day of the start of the technique.
Changes in the dyspnea score	Borg dyspnea score	From baseline to 6th hour, 12th hour, 18th hour and 24th hour of the first day of the start of the technique.
Patient-reported comfort scores	VAS (Visual Analogue Score)	From baseline to 6th hour, 12th hour, 18th hour and 24th hour of the first day of the start of the technique.
Rate of endotracheal intubation within first 24 hours or continuation on respiratory support after 24 hours.	Rate of endotracheal intubation within first 24 hours or continuation on respiratory support after 24 hours.	During the first 24 hours of the start of the technique
Length of stay in ICU and hospital	Length of stay in ICU and hospital	Total days of hospital stay starting from the day of starting the intervention protocol until patient discharge from ICU or death (up to 100 days)
Time to death in ICU/hospital	Time to death in ICU/hospital	Total days starting from the start of intervention protocol until patient death (if occurred) (Up to 100 days)

Collaborators and Investigators

• Sponsor: Minia University
• Collaborators: Minia University Hospital
• Investigators: Principal Investigator: Omyma S Mohamed, Prof., ahmed_ezz@mu.edu.eg

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2025
• Primary Completion (Estimated): April 1, 2026
• Study Completion (Estimated): May 1, 2026

Study Registration Dates

• First Submitted: November 26, 2025
• First Submitted That Met QC Criteria: April 7, 2026
• First Posted (Actual): April 9, 2026

Study Record Updates

• Last Update Posted (Actual): April 9, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Respiratory failure; High flow nasal oxygen; Noninvasive ventilation; Noninvasive technique in treatment of respiratory failure
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Respiratory Insufficiency
• Other Study ID Numbers: HFNC and NIV in ARF

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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