HNFO With or Without Helmet NIV for Oxygenation Support in Acute Respiratory Failure Pilot RCT (HONOUR)

High-flow Nasal Oxygen With or Without Helmet Non-invasive Ventilation for Oxygenation Support in Acute Respiratory Failure (the HONOUR Pilot Trial)

This Randomized Control Trial will directly compare helmet non-invasive ventilation (NIV) combined with high flow nasal oxygen (HFNO) versus HFNO alone in patients with Acute Hypoxemic Respiratory Failure (AHRF).

Study Overview

• Status: Active, not recruiting
• Conditions: Acute Hypoxemic Respiratory Failure
• Intervention / Treatment: Device: High Flow Nasal Oxygen; Device: Helmet Non-Invasive Ventilation (HNIV)

Detailed Description

This is a pilot multicentre, concealed, stratified, permuted block randomized controlled trial enrolling patients with AHRF who are admitted to the intensive care unit. Patients with imminent need for intubation, or a contraindication to study interventions will be excluded. Patients will be randomized to receive either (1) sessions of at least 12 hours per day of helmet NIV oxygen interspersed with HFNO or (2) HFNO alone over at least 2 calendar days. Participants will be followed to hospital discharge or 60 days, with an additional quality of life assessment via telephone interview 6 months after enrolment.

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T2N 4N1
      • University of Calgary
    • Edmonton, Alberta, Canada, T6G 2B7
      • University of Alberta Hospital
  • Ontario
    • Hamilton, Ontario, Canada
      • Hamilton Health Sciences- Juravinski
    • Kingston, Ontario, Canada
      • Kingston General Hospital
    • London, Ontario, Canada
      • London Health Sciences Centre
    • Ottawa, Ontario, Canada, K1H 8L6
      • Ottawa Hospital
    • Toronto, Ontario, Canada, M4N 3M5
      • Sunnybrook Health Sciences Centre
    • Toronto, Ontario, Canada, M5B 1W8
      • St. Michael's Hospital
    • Toronto, Ontario, Canada
      • Mount Sinai Hospital
    • Toronto, Ontario, Canada, M2K 1E1
      • North York General Hospital
    • Toronto, Ontario, Canada
      • University Health Network Toronto General

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Intensive care unit admission (orders written)
2. Age ≥18 years

3. Hypoxemic acute respiratory failure for at least 1 hour and still present at time of screening for eligibility (symptom onset during last 14 days) with the following:

   1. Respiratory rate >21bpm or clinical evidence of increased work of breathing and
   2. Documented Hypoxemia defined as any one of:

   i. PaO2:FiO2 < 300 ii. If no arterial blood gas available, then SpO2:FiO2 < 315 iii. Oxygen saturation <98% on FiO2 >= 0.4 or higher by Venturi mask, TAVISH mask 10 Litres / minute, or any non-invasive oxygenation strategy

4. Not already intubated or with tracheostomy

Exclusion Criteria:

1. Already on HFNO or other non-invasive ventilation strategy at FiO2>=0.4 for the last 24 hours in the ICU.
2. Immediate need for intubation (e.g., inadequate airway protection or refractory hypoxemia or cardiopulmonary arrest, massive hemoptysis, etc)
3. Extubated in the ICU within past 72 hours
4. Clinician deems that face mask NIV is indicated to treat a primary diagnosis of hypercapnic respiratory failure or acute congestive heart failure
5. Known neuromuscular disease
6. Patients being transitioned to Palliative care or unlikely to survive more than 24 hours
7. ICU discharge is planned or anticipated on the day of screening
8. Previously enrolled in this trial
9. Trauma patients who remain in a cervical spine collar at the time of recruitment or who have upper limb/torso fractures that would preclude them from safe application of the helmet
10. Clinician decision that positive pressure to face and/or nasal pharynx is a contraindication (eg. Transphenoidal surgery, basal skull fracture etc.)

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

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: HFNO; High Flow Nasal Oxygen alone	Device: High Flow Nasal Oxygen; HFNO will be provided. FiO2 will be titrated to achieve a target O2 saturation of 92-97%, and flows will be initiated at 50 litres/minute and titrated as per usual practice for comfort and oxygenation. Once the target O2 saturation is achieved, the FiO2 will be titrated to the minimal value to maintain this target saturation. HFNO will be provided continuously over a minimum of 2 calendar days. Starting on study day 3, patients will be weaned from HFNO as tolerated.; Other Names: HFNO
Active Comparator: H-NIV; Helmet Non-Invasive ventilation for a minimum of 12 hours per day with HFNO between sessions	Device: Helmet Non-Invasive Ventilation (HNIV); HNIV will be connected to a ventilator by a conventional closed respiratory circuit. Sessions of HNIV will be delivered with PEEP targeting a minimum 12 hours/day. PEEP will be titrated according to patient comfort, work of breathing, and O2 saturation. Pressure support will be titrated to lowest level tolerated. Between HNIV sessions, patients will be supported with HFNO at the same required FiO2. Starting on study day 3, patients will be screened for discontinuation of HNIV. Once HNIV is stopped, patients will be transitioned to HFNO and then weaned from HFNO as tolerated.; Other Names: HNIV

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recruitment Rates	Recruitment rate at different study sites	2 years
Non-randomized Eligible Patients	Proportion of Eligible patients who are not randomized and reasons for this	2 years
Adherence/Compliance to Oxygenation Strategy	Rate of adherence to the assigned oxygenation strategy (and crossover rates)	2 years
Among patients requiring intubation in each group, the number who were intubated according to the pre-specified criteria	Adherence to pre-specified criteria for intubation in each group	2 years
Time from ICU admission to randomization and initiation of treatment	Median time from ICU admission to randomization and initiation of the allocated treatment	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants in each group who need endotracheal intubation	Need for endotracheal intubation after randomization	28 and 60 days
Duration of invasive mechanical ventilation after randomization up to 28 and 60 days	Duration of invasive mechanical ventilation after randomization up to 28 and 60 days	28 and 60 days
Duration of non-invasive respiratory support after randomization up to 28 and 60 days	Duration of non-invasive mechanical ventilation after randomization up to 60 days	60 days
ICU length of stay	days of ICU up to 28 days after randomization	28 days
All cause mortality	All cause mortality to 60 days	60 days
COVID-19 infection after hospitalization	diagnosis of COVID-19	28 days
Health related quality of life	Health related quality of life as measured by telephone using the European Quality of Life Five Dimension (EQ-5D) tool, where a score of 1 means the patient has no problems, and a score of 5 mean the patient has extreme problems in the 5 dimensions.	180 days
Mortality at 180 days	Mortality to 180 days	180 days
Activities of Daily Living	Katz Index of Independence in Activities of Daily Living (ADL) where a high of 6 means the patient can perform the activities fully independently, and a low of 0 means the patient is fully dependent and unable to perform activities without assistance.	180 days
Ventilator-Free Days to day 28, analyzed as an ordinal variable, with death = 0 days	Ventilator-Free Days to day 28, analyzed as an ordinal variable, with death = 0 days	28 days

Collaborators and Investigators

• Sponsor: Sunnybrook Health Sciences Centre
• Investigators: Principal Investigator: Niall Fergusson, MD FRCPC, University Health Network, Toronto; Principal Investigator: Damon Scales, MD PhD FRCPC, Sunnybrook Health Sciences Centre

Publications and helpful links

General Publications

• Angriman F, Ferreyro BL, Rochwerg B, Sklar M, Adhikari N, Bagshaw SM, Brochard L, Cuthbertson B, Del Sorbo L, Fowler R, Geagea A, Granton JT, Mehta S, Munshi L, Muscedere J, Nardi J, Parhar K, Pinto RL, Piquette D, Seely A, Slessarev M, Tobin S, Scales DC, Ferguson ND; HONOUR Investigators and the Canadian Critical Care Trials Group. High-flow nasal Oxygen with or without alternating helmet Non-invasive ventilation for Oxygenation sUpport in acute Respiratory failure (HONOUR): a protocol for a pilot randomised controlled trial. BMJ Open. 2025 Oct 27;15(10):e111526. doi: 10.1136/bmjopen-2025-111526.

Study record dates

Study Major Dates

• Study Start (Actual): March 17, 2022
• Primary Completion (Estimated): March 1, 2026
• Study Completion (Estimated): August 1, 2026

Study Registration Dates

• First Submitted: October 1, 2021
• First Submitted That Met QC Criteria: October 1, 2021
• First Posted (Actual): October 14, 2021

Study Record Updates

• Last Update Posted (Actual): March 16, 2026
• Last Update Submitted That Met QC Criteria: March 12, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: High Flow Nasal Oxygen; Helmet Non Invasive Ventilation
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Respiratory Insufficiency
• Other Study ID Numbers: HONOUR (3693)

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