Airway ObstructionNCT06457399

Heliox on the Work of Breathing in Adult Patients With Lower Airway Stenosis

An observational study of Airway Obstruction, run by Hospital Universitario 12 de Octubre at 1 site in Spain.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

Search all trials

Trial summary

Who is it for?: Ages 18 to 80 years
Conditions the study is for: Airway Obstruction
What is being tested?: Heliox and Oxygen
How many people: 18 participants
Where: 1 siteSpain
Study dates: 27 Apr 2022to 10 Jan 2026
Phase: Observational
Are there results?: None posted in the registry

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 to 80 years
All sexes
No healthy volunteers
Adult, Older adult

Study population: Patients will be recluted from the pneumology outpatient clinic of the Hospital 12 de Octubre

Who may be able to join

Patients with lower airway stenosis evaluated at the Respiratory Endoscopy Unit of the Hospital Universitario 12 de Octubre on the waiting list for endoscopic intervention on stenosis.
Stenosis grade ≥ 3 and Borg scale score > 2.

Who cannot join

Presence of relevant comorbidities (uncontrolled ischemic heart disease, ventricular dysfunction, pneumopathies with severe respiratory insufficiency, severe pulmonary hypertension).
Inability to perform the test due to severe dyspnea or need for emergency intervention.
Patient on continuous mechanical ventilation, invasive or non-invasive.

Trial locations and contacts

1 site in 1 country.

Spain1 site

Marta Corral Blanco
Madrid, Madrid, 28041

Other trials in Spain

About this study

Official title: The Effect of Heliox on the Work of Breathing in Adult Patients With Lower Airway Stenosis

Heliox (a mixture of Helium and Oxygen) can reduce the work of breathing in patients with airway stenosis by modifying turbulent flow into laminar flow. The aim of this study was to analyze the effect of Heliox versus conventional oxygen therapy in patients with lower airway stenosis on muscular effort measured by electromyography and diaphragmatic ultrasound, thoracoabdominal synchrony assessed with plethysmographic bands, dyspnea, stridor, oxygen saturation, transcutaneous carbon dioxide value, blood pressure, heart rate and respiratory rate.

Read the detailed description

Lower airway stenosis results in increased work of breathing with stridor and dyspnea, as a consequence of the increased resistances caused by the reduction in airway diameter. Airway resistance also depends on the length of the airway and the type of gas flow. Heliox (a mixture of Helium and Oxygen) is a gas less dense than air, which can change the flow from turbulent to laminar, reducing airway resistance by 20 to 40%, and therefore decreasing the work of breathing. Heliox is an inert gas that does not react with biological membranes, so there are few complications associated with its use, the most relevant being hypoxemia when fixed mixtures are not used and the the fraction of inspired oxygen (FiO2) supplied is less than 21%. The aim of the study was to evaluate if during the perioperative period of lower airway stenosis the administration of Heliox compared to oxygen could reduce the work of breathing and improve dyspnea. For this purpose, patients were treated for 30 minutes with Heliox (fixed mixture of 70% helium and 30% oxygen) using a non rebreather mask or reservoir bag versus 30 minutes with oxygen 31% using a Venturi mask.

Conditions: Airway Obstruction
Being tested: Heliox, Oxygen
Keywords: Heliox, Airway Stenosis, Work of breathing, Airway resistance
Medical subject headings: Airway Obstruction

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

HelioxDrug
Also called Helium - Oxygen
Treatment for 30 minutes with Heliox from a commercial tank (Oxhelⓒ, Air Liquideⓒ) with a fixed mixture of 70% helium and 30% oxygen with non-rebreather mask or reservoir bag at a flow of 12-15 lpm.
OxygenDrug
Also called Oxygen 31%
Treatment for 30 minutes with oxygen at FiO2 of 31% with Venturi mask.

Study groups in NCT06457399
Study group	Role	What they receive
Airway Stenosis		Patients with lower airway stenosis on waiting list for endoscopic intervention on stenosis by respiratory endoscopy unit. Receives: Drug: Heliox; Drug: Oxygen

What is being measured

The primary outcome is the main question the study is designed to answer.

Changes in Neural Ventilatory Drive (%):
Percentage over the Root Mean Square peak for parasternal electromyography (EMG): averaged of the square root of the peak value and the area under the curve of parasternal EMG (%RootMeanSquare) adjusted for respiratory frequency, as a surrogate of diaphragmatic EMG, and sternocleidomastoid EMG, which will give us information on accessory muscle activation.
Measured: 30 minutes with Heliox and 30 minutes with Oxygen 31%

Secondary outcomes (9)

Diaphragmatic excursion assessed with ultrasound
Assessment of muscular effort by measuring the diaphragmatic excursion (mm) at tidal volume and at vital capacity.
Measured: At minute 15 during the Heliox test and at minute 15 during the Oxygen 31% test.
Thickening fraction of the diaphragm assessed by ultrasound
Assessment of muscular effort by measuring the thickening fraction of the diaphragm in the apposition zone (%).
Measured: At minute 15 during the Heliox test and at minute 15 during the Oxygen 31% test.
Changes in thoracoabdominal synchrony
Assessment of thoracoabdominal synchrony using thoracic and abdominal belts by calculating the phase angle with the Lissajoux loop method (plotting abdominal motion on the x-axis against thoracic motion on the y-axis).
Measured: Phase angle was calculated from 10 consecutive breaths at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Borg Scale Dyspnea evolution (points)
Degree of dyspnea will be determined by this validated scale with a result between 1 and 10 points.0: Not at all 0.5: Very, very light (hardly noticeable) 1: Very light, 2: Light, 3: Moderate , 4: Somewhat intense, 5: Intense, 6: Between 5 and 7, 7: Very intense, 8: Between 7 and 9, 9: Very, very intense (almost maximum ), 10: Maximum
Measured: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Oxygen saturation
Measured by pulse-oximetry
Measured: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Transcutaneous partial pressure of carbon dioxide
Transcutaneous monitor uses a noninvasive technique to measure the skin-surface partial pressure of carbon dioxide (PtcCO2)
Measured: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Blood pressure
Non-invasive measurement with a sphygmomanometer
Measured: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Heart rate
number of beats per minute
Measured: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Respiratory rate
Number of breaths per minute
Measured: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

27 Apr 202210 Jan 2026

First posted13 Jun 2024
Study start27 Apr 2022
Primary completion31 May 2023
Study completion10 Jan 2026

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Other trials for Airway ObstructionStudies 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: Observational
Observational model: Cohort
Time perspective: Prospective
Enrolment: 18 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT06457399
Sponsor's protocol ID: HELIOX ON AIRWAY STENOSIS
Status last verified: Sep 2026
First submitted: 30 May 2024
Last updated: 23 Sep 2026
Results posted: No
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

RecruitingPhase 2
A Study to Learn About the Study Medicine Called PF-07275315 in People With Moderate-To-Severe Asthma
Asthma
Not yet recruiting
Influence of Patient Positioning During Nasal Lavage
Acute Upper Respiratory Tract Infections, Nasal Obstruction
RecruitingPhase 1/2
Interstitial Photodynamic Therapy Following Palliative Radiotherapy in Treating Patients With Inoperable Malignant Central Airway Obstruction
Malignant Solid Neoplasm
Recruiting
Pharyngeal Mucosal Conditioning to Prevent Postoperative Sore Throat in Septoplasty Patients With Severe Nasal Obstruction
Postoperative Sore Throat, Nasal Obstruction
Active, not recruitingObservational study
A Prospective Study Comparing VivAer to Alternative Surgical Procedures to Treat Nasal Airway Obstruction in Patients With Nasal Valve Dysfunction.
Nasal Airway Obstruction

All Airway Obstruction trials

Study at a glance

From the registry record, last updated by the sponsor on 23 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: The Effect of Heliox on the Work of Breathing in Adult Patients With Lower Airway Stenosis
ClinicalTrials.gov ID: NCT06457399
Acronym / sponsor ID: HELIOX ON AIRWAY STENOSIS
Conditions: Airway Obstruction
Keywords: Heliox, Airway Stenosis, Work of breathing, Airway resistance
Study type: Observational
Recruitment status: Completed
Enrolment: 18 participants (actual)
Lead sponsor: Hospital Universitario 12 de OctubreUniversity, hospital or other
Study start: 27 Apr 2022 (actual)
Primary completion: 31 May 2023 (actual)
Study completion: 10 Jan 2026 (actual)
First posted: 13 Jun 2024 (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.

Detailed description

Study design

Observational model: Cohort
Time perspective: Prospective
Number of arms: 1

Arm	Type	Receives
Airway Stenosis	–	Drug: Heliox, Drug: OxygenPatients with lower airway stenosis on waiting list for endoscopic intervention on stenosis by respiratory endoscopy unit.

Who may qualify

Ages: 18 to 80 years
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult
Study population: Patients will be recluted from the pneumology outpatient clinic of the Hospital 12 de Octubre

Key inclusion criteria (2 listed)

Patients with lower airway stenosis evaluated at the Respiratory Endoscopy Unit of the Hospital Universitario 12 de Octubre on the waiting list for endoscopic intervention on stenosis.
Stenosis grade ≥ 3 and Borg scale score > 2.

Key exclusion criteria (3 listed)

Presence of relevant comorbidities (uncontrolled ischemic heart disease, ventricular dysfunction, pneumopathies with severe respiratory insufficiency, severe pulmonary hypertension).
Inability to perform the test due to severe dyspnea or need for emergency intervention.
Patient on continuous mechanical ventilation, invasive or non-invasive.

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
HelioxAlso: Helium - OxygenTreatment for 30 minutes with Heliox from a commercial tank (Oxhelⓒ, Air Liquideⓒ) with a fixed mixture of 70% helium and 30% oxygen with non-rebreather mask or reservoir bag at a flow of 12-15 lpm.	Drug	Airway Stenosis
OxygenAlso: Oxygen 31%Treatment for 30 minutes with oxygen at FiO2 of 31% with Venturi mask.	Drug	Airway Stenosis

Primary outcome

Changes in Neural Ventilatory Drive (%):
Time frame: 30 minutes with Heliox and 30 minutes with Oxygen 31%
Percentage over the Root Mean Square peak for parasternal electromyography (EMG): averaged of the square root of the peak value and the area under the curve of parasternal EMG (%RootMeanSquare) adjusted for respiratory frequency, as a surrogate of diaphragmatic EMG, and sternocleidomastoid EMG, which will give us information on accessory muscle activation.

9 secondary outcomes

Diaphragmatic excursion assessed with ultrasound
Time frame: At minute 15 during the Heliox test and at minute 15 during the Oxygen 31% test.
Thickening fraction of the diaphragm assessed by ultrasound
Time frame: At minute 15 during the Heliox test and at minute 15 during the Oxygen 31% test.
Changes in thoracoabdominal synchrony
Time frame: Phase angle was calculated from 10 consecutive breaths at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Borg Scale Dyspnea evolution (points)
Time frame: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Oxygen saturation
Time frame: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Transcutaneous partial pressure of carbon dioxide
Time frame: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Blood pressure
Time frame: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Heart rate
Time frame: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.
Respiratory rate
Time frame: Basal value and at minutes 1, 5, 15 and 30 during the Heliox test and the Oxygen 31% test.

Results and safety

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 23 Sep 2026.

Related trials for Airway Obstruction

RecruitingPhase 2
A Study to Learn About the Study Medicine Called PF-07275315 in People With Moderate-To-Severe Asthma
Asthma
Not yet recruiting
Influence of Patient Positioning During Nasal Lavage
Acute Upper Respiratory Tract Infections, Nasal Obstruction
RecruitingPhase 1/2
Interstitial Photodynamic Therapy Following Palliative Radiotherapy in Treating Patients With Inoperable Malignant Central Airway Obstruction
Malignant Solid Neoplasm
Recruiting
Pharyngeal Mucosal Conditioning to Prevent Postoperative Sore Throat in Septoplasty Patients With Severe Nasal Obstruction
Postoperative Sore Throat, Nasal Obstruction
Active, not recruitingObservational study
A Prospective Study Comparing VivAer to Alternative Surgical Procedures to Treat Nasal Airway Obstruction in Patients With Nasal Valve Dysfunction.
Nasal Airway Obstruction

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. This study is not recruiting at the moment.

Marta Corral Blanco, MD principal investigator

Hospital 12 de Octubre

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 Airway Obstruction, run by Hospital Universitario 12 de Octubre at 1 site in Spain.

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 2 inclusion and 3 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: finished, as of the sponsor's last update on 23 Sep 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 Spain. 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?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in Neural Ventilatory Drive (%): (time frame: 30 minutes with Heliox and 30 minutes with Oxygen 31%). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06457399.

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 23 Sep 2026.