Acute Respiratory FailureEFI-HFNONCT07366541
Predicting High-Flow Nasal Oxygen Failure Within 72 Hours Using a Physiology-Informed Dual-Domain Model at 30 Minutes
An observational study of Acute Respiratory Failure and Electrical Impedance Tomography (EIT), run by Ruijin Hospital at 1 site in China.
Trial summary
This is a single-center, ambispective observational cohort study of adults with acute hypoxemic respiratory failure (AHRF) receiving high-flow nasal oxygen (HFNO) as initial respiratory support. The study includes three stages. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Acute Respiratory Failure, Electrical Impedance Tomography (EIT), High-Flow Nasal Oxygen Therapy
- What is being tested?
- High-Flow Nasal Oxygen Therapy and Electrical Impedance Tomography Monitoring
- Type of treatment
- Medical device
- How many people
- 115 participants
- Where
- 1 siteChina
- Study dates
- 1 May 2025to 31 Dec 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients with acute respiratory failure receiving HFNO
Who may be able to join
- Age ≥18 years
- Acute hypoxemic respiratory failure (AHRF) requiring HFNO initiation
- At least one of the following high-risk criteria: a) PaO₂/FiO₂ ≤200 mmHg or FiO₂ ≥0.40 to maintain SpO₂ ≥92%; b) Respiratory rate ≥25/min; c) APACHE II score ≥12; d) Bilateral infiltrates on chest imaging
Who cannot join
- Neuromuscular disease affecting spontaneous breathing
- Pregnancy
- Contraindication to EIT (e.g., chest wall wounds, pacemaker)
- Do-not-intubate order
- Hypercapnic respiratory failure as primary diagnosis (PaCO₂ >50 mmHg with pH <7.30 at baseline, unless mixed mechanism)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine
Shanghai, Shanghai Municipality, 200025
Rui Zhang, 02164370045, ccmzhangrui@foxmail.com
About this study
Official title: A Physiology-Informed Dual-Domain Model for 30-Minute Reassessment to Predict Endotracheal Intubation Within 72 Hours After High-Flow Nasal Oxygen Initiation in Adults With Acute Hypoxemic Respiratory Failure: A Retrospective Derivation and Multicenter Prospective Validation Study
This is a single-center, ambispective observational cohort study of adults with acute hypoxemic respiratory failure (AHRF) receiving high-flow nasal oxygen (HFNO) as initial respiratory support. The study includes three stages. Stage 1 (retrospective derivation): the first 57 consecutive patients (May-September 2025) were retrospectively included to develop and lock a dual-domain logistic model using baseline EFI, baseline PaCO2, and 0-30 minute changes in respiratory rate (ΔRR) and SpO2 (ΔSpO2). Stage 2 (retrospective temporal validation): the later 58 patients (October 2025-March 2026) were retrospectively included, and the frozen model was directly applied without refitting; results of Stages 1 and 2 have been reported. Stage 3 (prospective validation): an independent prospective validation cohort is currently being enrolled, and the frozen model will be applied without refitting. The primary outcome is endotracheal intubation within 72 hours after HFNO initiation. This registration covers the complete study; the retrospective stages have been reported, and the prospective stage is ongoing.
Read the detailed description
This was a single-center, ambispective observational cohort study conducted at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, between May 2025 and March 2026, with an ongoing prospective validation stage. Adults with AHRF receiving HFNO as initial respiratory support were included. Patients with an immediate indication for endotracheal intubation, severe hemodynamic instability, marked consciousness disturbance or inability to cooperate with monitoring, or missing/inadequate EIT data were excluded. Clinical, physiological, blood gas, and EIT data were collected at baseline before HFNO and at 30 minutes after HFNO initiation. EFI was calculated from the global EIT impedance curve.
Stage 1 (retrospective derivation): the first 57 consecutive patients were included retrospectively; baseline EFI, baseline PaCO2, ΔRR, and ΔSpO2 were used to develop and lock a dual-domain logistic model.
Stage 2 (retrospective temporal validation): the later 58 patients were included retrospectively; the frozen model coefficients were directly applied without refitting. Results of Stages 1 and 2 have been reported.
Stage 3 (prospective validation): an independent multicenter prospective validation cohort is currently being enrolled. The same inclusion/exclusion criteria, 30-minute reassessment protocol, and frozen model will be applied without refitting.
The primary endpoint is endotracheal intubation within 72 hours after HFNO initiation.
The retrospective stages were approved by the Ethics Committee of Ruijin Hospital (Approval No. 2025232), and informed consent was waived. The prospective validation stage was approved by the same committee (Approval No. (2026592), and written informed consent is obtained from all prospectively enrolled participants.
- Conditions
- Acute Respiratory Failure, Electrical Impedance Tomography (EIT), High-Flow Nasal Oxygen Therapy
- Being tested
- High-Flow Nasal Oxygen Therapy, Electrical Impedance Tomography Monitoring
- Keywords
- Acute hypoxemic respiratory failure, High-flow nasal oxygen, Electrical impedance tomography, EIT-derived flow index, Prediction model, Multicenter prospective validation
- Medical subject headings
- Respiratory Insufficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High-Flow Nasal Oxygen TherapyOther
Patients received HFNO as part of standard clinical care for acute hypoxemic respiratory failure. The treatment was titrated by the clinical team based on physiological parameters (SpO2, RR, ABG), aiming to maintain SpO2 ≥ 92% and reduce signs of respiratory distress.
Electrical Impedance Tomography MonitoringDevice
PulmoVista 500 EIT device (Dräger Medical, Lübeck, Germany) was used for continuous real-time monitoring of regional lung ventilation and to derive the EIT-derived flow index (EFI) at baseline and 30 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Retrospective derivation cohort | First 57 consecutive adults with AHRF receiving HFNO (May-September 2025); used to develop and lock the dual-domain model. Completed. Receives: Other: High-Flow Nasal Oxygen Therapy; Device: Electrical Impedance Tomography Monitoring | |
| Retrospective temporal validation cohort | Later 58 adults with AHRF receiving HFNO (October 2025-March 2026); frozen model applied without refitting. Completed. Receives: Other: High-Flow Nasal Oxygen Therapy; Device: Electrical Impedance Tomography Monitoring | |
| Prospective validation cohort | Independent adults with AHRF receiving HFNO; currently being prospectively enrolled at multiple centers. Frozen model applied without refitting. Ongoing. Receives: Other: High-Flow Nasal Oxygen Therapy; Device: Electrical Impedance Tomography Monitoring |
What is being measured
The primary outcome is the main question the study is designed to answer.
HFNO Failure (Endotracheal Intubation Within 72 Hours)
HFNO failure was defined as endotracheal intubation within 72 hours after HFNO initiation due to refractory hypoxemia, progressive respiratory acidosis, severe respiratory distress, or hemodynamic instability. Escalation to noninvasive ventilation (NIV) without endotracheal intubation and within-tier adjustments (increasing flow or FiO2 without changing support modality) were NOT considered the primary failure event. The model is intended for reassessment at 30 minutes, but the outcome is assessed within 72 hours.Unit of Measure:
Proportion of participants.
Measured: Within 72 hours after HFNO initiation.
Secondary outcomes (4)
Model Discrimination in Retrospective Temporal Validation
Area under the receiver operating characteristic curve (AUC) of the frozen dual-domain model for predicting endotracheal intubation within 72 hours in the retrospective temporal validation cohort.Unit of Measure:
AUC (dimensionless, 0-1).
Measured: Within 72 hours after HFNO initiation.
Model Calibration in Retrospective Temporal Validation
Calibration intercept and slope of the frozen dual-domain model in the retrospective temporal validation cohort. Unit of Measure: Dimensionless.
Measured: Within 72 hours after HFNO initiation.
Model Discrimination in Prospective Validation
AUC of the frozen dual-domain model for predicting endotracheal intubation within 72 hours in the ongoing prospective validation cohort.Unit of Measure:
AUC (dimensionless, 0-1).
Measured: Within 72 hours after HFNO initiation.
Model Calibration in Prospective Validation
Calibration intercept and slope of the frozen dual-domain model in the ongoing prospective validation cohort. Unit of Measure: Dimensionless.
Measured: Within 72 hours after HFNO initiation.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Jan 2026
- Study start1 May 2025
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Acute Respiratory FailureStudies of the same condition, open and under way.
- More trials run by Ruijin HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Other
- Enrolment
- 115 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ruijin Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Hongping Qu, Study chair, Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07366541
- Sponsor's protocol ID
- [2025]232 and [2026]592
- Other IDs
- (2026) Lin Lun Shen No. 592
- Acronym
- EFI-HFNO
- Status last verified
- Sep 2026
- First submitted
- 16 Jan 2026
- Last updated
- 8 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Physiology-Informed Dual-Domain Model for 30-Minute Reassessment to Predict Endotracheal Intubation Within 72 Hours After High-Flow Nasal Oxygen Initiation in Adults With Acute Hypoxemic Respiratory Failure: A Retrospective Derivation and Multicenter Prospective Validation Study
- ClinicalTrials.gov ID
- NCT07366541
- Acronym / sponsor ID
- EFI-HFNO / [2025]232 and [2026]592
- Conditions
- Acute Respiratory Failure, Electrical Impedance Tomography (EIT), High-Flow Nasal Oxygen Therapy
- Keywords
- Acute hypoxemic respiratory failure, High-flow nasal oxygen, Electrical impedance tomography, EIT-derived flow index, Prediction model, Multicenter prospective validation
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 115 participants (estimated)
- Lead sponsor
- Ruijin HospitalUniversity, hospital or other
- Study start
- 1 May 2025 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 26 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a single-center, ambispective observational cohort study of adults with acute hypoxemic respiratory failure (AHRF) receiving high-flow nasal oxygen (HFNO) as initial respiratory support. The study includes three stages. Stage 1 (retrospective derivation): the first 57 consecutive patients (May-September 2025) were retrospectively included to develop and lock a dual-domain logistic model using baseline EFI, baseline PaCO2, and 0-30 minute changes in respiratory rate (ΔRR) and SpO2 (ΔSpO2). Stage 2 (retrospective temporal validation): the later 58 patients (October 2025-March 2026) were retrospectively included, and the frozen model was directly applied without refitting; results of Stages 1 and 2 have been reported. Stage 3 (prospective validation): an independent prospective validation cohort is currently being enrolled, and the frozen model will be applied without refitting. The primary outcome is endotracheal intubation within 72 hours after HFNO initiation. This registration covers the complete study; the retrospective stages have been reported, and the prospective stage is ongoing.
Detailed description
This was a single-center, ambispective observational cohort study conducted at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, between May 2025 and March 2026, with an ongoing prospective validation stage. Adults with AHRF receiving HFNO as initial respiratory support were included. Patients with an immediate indication for endotracheal intubation, severe hemodynamic instability, marked consciousness disturbance or inability to cooperate with monitoring, or missing/inadequate EIT data were excluded. Clinical, physiological, blood gas, and EIT data were collected at baseline before HFNO and at 30 minutes after HFNO initiation. EFI was calculated from the global EIT impedance curve.
Stage 1 (retrospective derivation): the first 57 consecutive patients were included retrospectively; baseline EFI, baseline PaCO2, ΔRR, and ΔSpO2 were used to develop and lock a dual-domain logistic model.
Stage 2 (retrospective temporal validation): the later 58 patients were included retrospectively; the frozen model coefficients were directly applied without refitting. Results of Stages 1 and 2 have been reported.
Stage 3 (prospective validation): an independent multicenter prospective validation cohort is currently being enrolled. The same inclusion/exclusion criteria, 30-minute reassessment protocol, and frozen model will be applied without refitting.
The primary endpoint is endotracheal intubation within 72 hours after HFNO initiation.
The retrospective stages were approved by the Ethics Committee of Ruijin Hospital (Approval No. 2025232), and informed consent was waived. The prospective validation stage was approved by the same committee (Approval No. (2026592), and written informed consent is obtained from all prospectively enrolled participants.
Study design
- Observational model
- Cohort
- Time perspective
- Other
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Retrospective derivation cohort | – | Other: High-Flow Nasal Oxygen Therapy, Device: Electrical Impedance Tomography MonitoringFirst 57 consecutive adults with AHRF receiving HFNO (May-September 2025); used to develop and lock the dual-domain model. Completed. |
| Retrospective temporal validation cohort | – | Other: High-Flow Nasal Oxygen Therapy, Device: Electrical Impedance Tomography MonitoringLater 58 adults with AHRF receiving HFNO (October 2025-March 2026); frozen model applied without refitting. Completed. |
| Prospective validation cohort | – | Other: High-Flow Nasal Oxygen Therapy, Device: Electrical Impedance Tomography MonitoringIndependent adults with AHRF receiving HFNO; currently being prospectively enrolled at multiple centers. Frozen model applied without refitting. Ongoing. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients with acute respiratory failure receiving HFNO
Key inclusion criteria (3 listed)
- Age ≥18 years
- Acute hypoxemic respiratory failure (AHRF) requiring HFNO initiation
- At least one of the following high-risk criteria: a) PaO₂/FiO₂ ≤200 mmHg or FiO₂ ≥0.40 to maintain SpO₂ ≥92%; b) Respiratory rate ≥25/min; c) APACHE II score ≥12; d) Bilateral infiltrates on chest imaging
Key exclusion criteria (5 listed)
- Neuromuscular disease affecting spontaneous breathing
- Pregnancy
- Contraindication to EIT (e.g., chest wall wounds, pacemaker)
- Do-not-intubate order
- Hypercapnic respiratory failure as primary diagnosis (PaCO₂ >50 mmHg with pH <7.30 at baseline, unless mixed mechanism)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| High-Flow Nasal Oxygen TherapyPatients received HFNO as part of standard clinical care for acute hypoxemic respiratory failure. The treatment was titrated by the clinical team based on physiological parameters (SpO2, RR, ABG), aiming to maintain SpO2 ≥ 92% and reduce signs of respiratory distress. | Other | Prospective validation cohort, Retrospective derivation cohort, Retrospective temporal validation cohort |
| Electrical Impedance Tomography MonitoringPulmoVista 500 EIT device (Dräger Medical, Lübeck, Germany) was used for continuous real-time monitoring of regional lung ventilation and to derive the EIT-derived flow index (EFI) at baseline and 30 minutes. | Device | Prospective validation cohort, Retrospective derivation cohort, Retrospective temporal validation cohort |
Primary outcome
HFNO Failure (Endotracheal Intubation Within 72 Hours)
Time frame: Within 72 hours after HFNO initiation.
HFNO failure was defined as endotracheal intubation within 72 hours after HFNO initiation due to refractory hypoxemia, progressive respiratory acidosis, severe respiratory distress, or hemodynamic instability. Escalation to noninvasive ventilation (NIV) without endotracheal intubation and within-tier adjustments (increasing flow or FiO2 without changing support modality) were NOT considered the primary failure event. The model is intended for reassessment at 30 minutes, but the outcome is assessed within 72 hours.Unit of Measure: Proportion of participants.
4 secondary outcomes
Model Discrimination in Retrospective Temporal Validation
Time frame: Within 72 hours after HFNO initiation.
Model Calibration in Retrospective Temporal Validation
Time frame: Within 72 hours after HFNO initiation.
Model Discrimination in Prospective Validation
Time frame: Within 72 hours after HFNO initiation.
Model Calibration in Prospective Validation
Time frame: Within 72 hours after HFNO initiation.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Hongping Qu study chair
Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Acute Respiratory Failure and Electrical Impedance Tomography (EIT), run by Ruijin Hospital at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 8 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact rui zhang, Dr (0086-021-21666066, ccmzhangrui@foxmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
HFNO Failure (Endotracheal Intubation Within 72 Hours) (time frame: Within 72 hours after HFNO initiation.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Oct 2026.