Comparing asymmetrical and conventional high-flow nasal cannulas for respiratory failure

The Physiologic Effects of Asymmetrical Versus Conventional High-flow Nasal Cannula in Acute Respiratory Failure. A Randomized Crossover Study.

Not applicable Interventional Siriraj Hospital · NCT06204276

This study tests whether a new type of high-flow nasal cannula can help people with breathing problems breathe better compared to the standard version.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment40 (estimated)
Ages18 Years to 90 Years
SexAll
SponsorSiriraj Hospital Academic / other
Locations1 site (Bangkok Noi, Bangkok)
Trial IDNCT06204276 on ClinicalTrials.gov

What this trial studies

This study evaluates the physiological effects of asymmetrical high-flow nasal cannula (HFNC) versus conventional HFNC in patients experiencing acute respiratory failure. Participants will receive both types of cannulas at varying flow rates in a randomized order to assess differences in diaphragm and intercostal muscle activity, breathing patterns, gas exchange, and hemodynamic variables. The study aims to determine if the asymmetrical design offers any advantages over the conventional method in improving respiratory function.

Who should consider this trial

Good fit: Ideal candidates include adults over 18 with acute hypoxemic respiratory failure requiring high-flow nasal cannula support.

Not a fit: Patients with respiratory acidosis, hemodynamic instability, or severe neuromuscular diseases may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved respiratory support strategies for patients with acute respiratory failure.

How similar studies have performed: Previous studies have shown that high-flow nasal cannula therapy can significantly improve outcomes in acute respiratory failure, suggesting potential for success with this novel asymmetrical approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Patients with acute hypoxemia respiratory failure

Inclusion Criteria:

* Age \> 18 years old
* Acute respiratory failure within 7 days of hospital admission?
* Hypoxemia defined by arterial partial pressure of oxygen (PaO2)/FiO2 \< 300 mmHg or SpO2/FiO2 \< 315
* Already supported with HFNC device

Exclusion Criteria:

* Respiratory acidosis: pH \< 7.30 and PaCO2 \> 45 mmHg
* Hemodynamic instability requiring vasopressor initiation
* Diminished level of consciousness or uncooperative
* Active hemoptysis or pneumothorax requiring a chest tube
* Chronic severe neuromuscular disease
* Pregnancy

Patients with acute hypercapnic COPD Inclusion criteria

* Age \> 40 years old
* Diagnosed COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guideline (postbronchodilator forced expiratory volume at 1 second (FEV1)/forced vital capacity (FVC) \< 70%)
* Exacerbation requiring hospitalization; at least 2 of the following criteria

  1. Respiratory rate \> 24/min
  2. Use of respiratory accessory muscles or paradoxical motion of the abdomen
  3. Acute respiratory acidosis with arterial or venous pH \< 7.35 and/or PaCO2 \> 45 mmHg

Exclusion criteria

* pH \< 7.25
* Hemodynamic instability requiring vasopressor initiation
* Persistent hypoxemia despite supplemental oxygen therapy
* Diminished level of consciousness or uncooperative
* Active hemoptysis or pneumothorax requiring a chest tube
* Associated severe chronic neuromuscular disease
* Pregnancy

Where this trial is running

Bangkok Noi, Bangkok

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Acute Hypoxemic Respiratory FailureAcute Hypercapnic Respiratory Failurehigh-flow nasal cannularespiratory failurerespiratory musclesultrasound
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.