Acute Respiratory Failure (ARF)NCT07247318
The Effects of Different Non-invasive Respiratory Support
A study testing Continuous Positive Airway Pressure, Non-invasive ventilation and High-flow nasal oxygen in people with Acute Respiratory Failure (ARF), run by Southeast University, China.
Trial summary
Patients with acute hypoxemic respiratory failure (AHRF) typically present with pathophysiological alterations characterized by the coexistence of respiratory dysfunction and hypoxemia. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Acute Respiratory Failure (ARF)
- What is being tested?
- Continuous Positive Airway Pressure, Non-invasive ventilation and High-flow nasal oxygen
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- No sites listed yet
- Study dates
- 30 Nov 2025to 31 Dec 2026
- Phase
- Interventional
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
Who may be able to join
- Age ≥ 18 years;
- PaO₂/FiO₂ ≤ 300 mmHg or SpO₂/FiO₂ ≤ 315 (with SpO₂ ≤ 97%);
- Requiring one of the following respiratory supports:
- Noninvasive positive pressure ventilation with PEEP ≥ 5 cmH₂O, or
- High-flow nasal oxygen therapy with a flow rate ≥ 30 L/min, or
- Conventional oxygen therapy with an oxygen flow ≥ 10 L/min, where FiO₂ is calculated using the formula: FiO₂ = 0.21 + (oxygen flow rate × 0.03).
Who cannot join
- Received CPAP or NIV for more than 24 hours prior to screening.
- Received invasive mechanical ventilation during the current hospitalization.
- Presence of chronic underlying pulmonary disease, or PaCO₂ ≥ 45 mmHg.
- Presence of cardiogenic pulmonary edema.
- Hemodynamic instability, defined as systolic blood pressure < 90 mmHg or norepinephrine-equivalent dose > 0.3 µg/kg/min.
- Impaired consciousness (GCS ≤ 12).
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- Patients requiring urgent intubation, including those with respiratory or cardiac arrest, apnea with loss of consciousness or gasping, or severe hypoxemia (defined as SpO₂ < 90% despite 100% oxygen).
- Contraindications to NIV: cardiac or respiratory arrest, coma, untreated pneumothorax, uncontrollable vomiting, upper airway obstruction, hematemesis or severe facial trauma, or thoracic/abdominal surgery within the past 7 days.
- Contraindications to EIT: implanted cardiac pacemaker, unstable spinal injury or fracture, or open chest trauma.
- Refusal of endotracheal intubation.
- Pregnancy.
About this study
Official title: The Physiological Effects of Different Non-invasive Respiratory Support in Patients With Acute Hypoxemic Respiratory
Patients with acute hypoxemic respiratory failure (AHRF) typically present with pathophysiological alterations characterized by the coexistence of respiratory dysfunction and hypoxemia. Respiratory dysfunction leads to dyspnea, increased work of breathing, use of accessory respiratory muscles, and hypercapnia, while gas exchange impairment results in hypoxemia. Studies have shown that hypercapnia, acidosis, and hypoxemia can all enhance inspiratory effort, which further increases negative intrathoracic pressure. In these patients, regional differences in airway resistance and lung compliance are often present, causing redistribution of air within the lungs. This redistribution manifests as gas movement from non-dependent to dependent regions, known as "pendelluft," which amplifies regional alveolar strain and ventilation heterogeneity. This phenomenon becomes more pronounced during noninvasive respiratory support when spontaneous breathing is preserved.
Noninvasive respiratory support strategies mainly include high-flow nasal oxygen (HFNO), noninvasive positive pressure ventilation (NIV), and continuous positive airway pressure (CPAP). HFNO delivers high-flow gas through nasal cannulas, generating a certain level of positive end-expiratory pressure (PEEP) and flushing out anatomical dead space to improve gas exchange, thereby reducing inspiratory effort, lowering the work of breathing, and enhancing oxygenation. NIV, typically using pressure support ventilation (NIV-PSV), is a patient-triggered, pressure-targeted mode that provides inspiratory positive pressure above PEEP. By augmenting tidal volume and reducing inspiratory effort, NIV improves gas exchange; however, leaks may limit the effective delivery of PEEP, and full inspiratory synchronization can increase transpulmonary driving pressure and tidal volume. CPAP, by contrast, delivers a constant positive pressure during both inspiration and expiration. Compared with HFNO, CPAP generates higher PEEP, which facilitates alveolar recruitment and more effectively improves oxygenation. Relative to NIV, CPAP may reduce transpulmonary driving pressure and tidal volume.
Different noninvasive respiratory support strategies exert varying effects on respiratory drive and regional lung strain, leading to differences in the occurrence and magnitude of pendelluft. Physiological studies have suggested that CPAP may offer greater benefits in improving oxygenation and reducing inspiratory effort; however, whether it can mitigate the occurrence and extent of pendelluft remains uncertain. Therefore, this study was conducted to visualize and quantitatively assess pendelluft in real time using electrical impedance tomography (EIT), aiming to verify whether CPAP has a superior effect in reducing pendelluft in patients with AHRF.
- Conditions
- Acute Respiratory Failure (ARF)
- Being tested
- Continuous Positive Airway Pressure, Non-invasive ventilation, High-flow nasal oxygen
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Continuous Positive Airway PressureDevice
Patients were placed at a 45-degree supine position, and noninvasive ventilation was delivered to the patient through a face mask connected to an ICU ventilator. 2.PEEP was started at 5 cm H2O with a FiO2 of 0.5 at initiation. PEEP and FiO2 were titrated to maintain SpO2 between 94 and 98%, remaining constant for at least 5 min. 3.CPAP was initiated with a first session of at least 4 h, the minimally required duration of noninvasive ventilation was 16 hours per day for at least 2 calendar days. Between noninvasive-ventilation sessions, patients received HFNO.
Non-invasive ventilationDevice
Patients were placed at a 45-degree supine position, and noninvasive ventilation was also delivered to the patient through a face mask connected to an ICU ventilator. The mask most appropriate for the patient will be selected and adjusted to minimize leakage and pressure points. 2. The inspiratory positive airway pressure (pressure support plus PEEP) was initiated between 12 and 14 cm H2O, PEEP was started at 5 cm H2O with a FiO2 of 0.5 at initiation. FiO2 was titrated to maintain SpO2 between 94 and 98%, remaining constant for at least 5 min. 3. NIV was initiated with a first session of at least 4 h, the minimally required duration of noninvasive ventilation was 16 hours per day for at least 2 calendar days. Between noninvasive-ventilation sessions, patients received HFNO.
High-flow nasal oxygenDevice
Oxygen was passed through a heated humidifier (MR850, Fisher and Paykel Healthcare) and applied continuously through large-bore binasal prongs, with a gas flow rate of 50 liters per minute and an FiO2 of 0.5 at initiation. HFNO heating temperature was prespecified at 37°C. 2.FiO2 will be titrated to maintain SpO2 between 94 and 98%, remaining constant for at least 5 min. 3.HFNO was applied for at least 2 calendar days.
| Study group | Role | What they receive |
|---|---|---|
| CPAP group | Experimental | Patients will receive continuous positive airway pressure Receives: Device: Continuous Positive Airway Pressure |
| NIV group | Experimental | Patients will receive non-invasive ventilation Receives: Device: Non-invasive ventilation |
| HFNO group | Experimental | Patients will receive HFNO Receives: Device: High-flow nasal oxygen |
What is being measured
The primary outcome is the main question the study is designed to answer.
Magnitude of Pendelluft
magnitude of Pendelluft using a software based on electrical impedance tomography monitoring
Measured: during the first 48 hours
Secondary outcomes (8)
pH
Arterial blood gas analysis
Measured: during the first 48 hours
Partial pressure of oxygen (PaO2)
Arterial blood gas analysis
Measured: during the first 48 hours
Partial Pressure of Carbon Dioxide (PaCO2)
Arterial blood gas analysis
Measured: during the first 48 hours
Pao2/FiO2
Arterial blood gas analysis
Measured: during the first 48 hours
Occlusion pressure at 100 ms (P0.1)
Monitoring with non-invasive ventilator
Measured: during the first 48 hours
Occluded inspiratory airway pressure (Pocc)
Monitoring with a non-invasive ventilator
Measured: during the first 48 hours
center of ventilation
monitoring with EIT
Measured: during the first 48 hours
RVD
Monitoring with EIT
Measured: during the first 48 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Nov 2025
- Study start30 Nov 2025 (estimated)
- 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 Failure (ARF)Studies of the same condition, open and under way.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Southeast University, China
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ling Liu, Southeast University, China
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07247318
- Sponsor's protocol ID
- Non-invasive support
- Status last verified
- Nov 2025
- First submitted
- 14 Nov 2025
- Last updated
- 25 Nov 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No