Standard Oxygen Versus High Flow Nasal Cannula Oxygen Therapy in Patients With Acute Hypoxemic Respiratory Failure (SOHO)

Impact on Mortality of an Oxygenation Strategy Including Standard Oxygen Versus High Flow Nasal Cannula Oxygen Therapy in Patients With Acute Hypoxemic Respiratory Failure: a Prospective, Randomized Controlled Trial.

First-line therapy of patients with acute respiratory failure consists in oxygen delivery through standard oxygen, high-flow nasal oxygen therapy through cannula or non-invasive ventilation. Non-invasive ventilation in acute hypoxemic respiratory failure is not recommended. In a large randomized controlled study, high-flow nasal oxygen has been described as superior to non-invasive ventilation and standard oxygen in terms of mortality but not of intubation. Paradoxically in immunocompromised patients, high-flow nasal oxygen has not been shown to be superior to standard oxygen. To improve the level of evidence of daily clinical practice, we propose comparing high-flow nasal oxygen versus standard oxygen, in terms of mortality in all patients with acute hypoxemic respiratory failure

Study Overview

• Status: Completed
• Conditions: Acute Respiratory Failure; Hypoxemic Respiratory Failure
• Intervention / Treatment: Other: Standard oxygen; Other: High-flow nasal oxygen therapy

• Study Type: Interventional
• Enrollment (Actual): 1504
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Poitiers, France, 86000
    • CHU Poitiers

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

All consecutive patients older than 18 years with an acute hypoxemic respiratory failure will be enrolled if they meet all the following criteria:

• Respiratory rate >25 breaths/min whatever the oxygen support
• Pulmonary infiltrate,
• PaO2/FiO2 ≤200 mmHg
• Informed consent from the patient or relatives.

Exclusion Criteria:

• PaCO2 > 45 mm Hg
• Need for emergent intubation: pulse oximetry < 90% with maximum oxygen support, respiratory arrest, cardiac arrest, or Glasgow coma scale below 8 points
• Hemodynamic instability defined by signs of hypoperfusion or use of vasopressors > 0.3 µg/kg/min
• Glasgow coma scale equal to or below 12 points
• Exacerbation of chronic lung disease including chronic obstructive pulmonary disease (grade 3 or 4 of Gold classification), or another chronic lung disease with long term oxygen or ventilatory support
• Cardiogenic pulmonary edema as main reason for acute respiratory failure
• Coronavirus SARS-2 infection as reason for acute respiratory failure (the SOHO-COVID study has been completed)
• Post-extubation respiratory failure within 7 days after extubation,
• Post-operative patients within 7 days after abdominal or cardiothoracic surgery,
• Do not intubate order;
• Already included in the study, refusal to participate or participation in another interventional study with the same primary outcome.
• Patients without any healthcare insurance scheme or not benefiting from it through a third party,
• Persons under law protection, namely minors, pregnant or breastfeeding women, persons deprived of their liberty by a judicial or administrative decision.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: standard oxygen group; In order to maintain SpO2 between 92 and 96%	Other: Standard oxygen; Standard low flow oxygen therapy through facemask or non-rebreathing mask at least 10 L/min.
Experimental: high-flow nasal cannula oxygen group; At least 50 L/min adjusted in order to maintain SpO2 between 92 and 96 %	Other: High-flow nasal oxygen therapy; Humidified and heated oxygen with a gas flow at least 50 l/min through nasal cannula and inspired fraction of oxygen adjusted in order to maintain a SpO2 between 92 and 96%

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mortality at 28 days after randomization	Death between randomization and 28 days after randomization	Day 28

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Failure of the oxygenation strategy between randomization and D28	Intubation between randomization and D28	Day 28
Mortality in ICU, in hospital, and day 90	Death between randomization and end of stay in ICU, hospital. Death between randomization and day 90.	Day 90
Number of ventilation free days at Day 28	days alive and without intubation between day 1 and day 28	Day 28
Duration of ICU and hospital stay	ICU and hospital stay between randomisation and end of stay in ICU and hospital	Day 90
Complications during the ICU stay	Complications during the ICU stay include: septic shock, nosocomial pneumonia, cardiac arrhythmia, and cardiac arrest.	Day 90
Organ Failure during the 48 hours after intubation.	Organ failure is evaluated by the Sepsis-related Organ Failure Assessment (SOFA) score during the 48 hours after intubation.	Day 28
Duration between the time when prespecified criteria of intubation are met and intubation	interval between the time when prespecified criteria of intubation are met and intubation	Day 28
Duration between treatment initiation and intubation	Interval between treatment initiation and intubation	Day 28
Dyspnea	feeling is evaluated using a 5-point Likert scale, indicating marked improvement (+2), slight improvement (+1), no change (0), slight deterioration (-1) and marked deterioration (-2)	Hour 1
Comfort	comfort is evaluated using a 100-mm visual-analogue scale, from 0, i.e. "no discomfort", to100, i.e. "maximal imaginable discomfort"	Hour [1;6]
Level of oxygenation	Oxygenation is assessed by arterial blood gas sample	Hour [1;6]

Collaborators and Investigators

• Sponsor: Poitiers University Hospital
• Investigators: Principal Investigator: Jean-Pierre FRAT, PhD, CHU Poitiers

Publications and helpful links

General Publications

• Frat JP, Quenot JP, Badie J, Coudroy R, Guitton C, Ehrmann S, Gacouin A, Merdji H, Auchabie J, Daubin C, Dureau AF, Thibault L, Sedillot N, Rigaud JP, Demoule A, Fatah A, Terzi N, Simonin M, Danjou W, Carteaux G, Guesdon C, Pradel G, Besse MC, Reignier J, Beloncle F, La Combe B, Prat G, Nay MA, de Keizer J, Ragot S, Thille AW; SOHO-COVID Study Group and the REVA Network. Effect of High-Flow Nasal Cannula Oxygen vs Standard Oxygen Therapy on Mortality in Patients With Respiratory Failure Due to COVID-19: The SOHO-COVID Randomized Clinical Trial. JAMA. 2022 Sep 27;328(12):1212-1222. doi: 10.1001/jama.2022.15613.
• Frat JP, Coudroy R, Quenot JP, Guitton C, Badie J, Gacouin A, Ehrmann S, Demoule A, Jarousseau F, Carteaux G, Rigaud JP, Reignier J, Sedillot N, Contou D, Beloncle F, Daubin C, Dureau AF, Fatah A, Besse MC, Ferre A, Turbil E, Merdji H, Galerneau LM, Lacombe B, Richard JC, Romen A, Delbove A, Prat G, Lautrette A, Colin G, Soum E, Bourdin G, Hernandez G, Ragot S, Thille AW; REVA network. Effect of high-flow nasal cannula oxygen versus standard oxygen on mortality in patients with acute hypoxaemic respiratory failure: protocol for a multicentre, randomised controlled trial (SOHO). BMJ Open. 2024 Oct 23;14(10):e083232. doi: 10.1136/bmjopen-2023-083232.

Study record dates

Study Major Dates

• Study Start (Actual): January 19, 2021
• Primary Completion (Actual): October 30, 2024
• Study Completion (Actual): December 31, 2024

Study Registration Dates

• First Submitted: July 8, 2020
• First Submitted That Met QC Criteria: July 8, 2020
• First Posted (Actual): July 13, 2020

Study Record Updates

• Last Update Posted (Actual): January 22, 2026
• Last Update Submitted That Met QC Criteria: January 20, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: acute hypoxemic respiratory failure; de novo respiratory failure; high-flow nasal oxygen; standard oxygen
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Respiratory Insufficiency
• Other Study ID Numbers: SOHO

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Our institution does not have a data sharing platform.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No