An interventional study of Heated Humidified Nasal High-Flow Therapy in Chronic Obstructive Pulmonary Disease (COPD), sponsored by ADIR Association. Not yet recruiting at 1 site in France. Open to participants aged 18 Years to 85 Years. Per ClinicalTrials.gov, last updated 2026-08-10.
Sponsored by ADIR Association · Not applicable, Interventional, and Basic science
Chronic obstructive pulmonary disease (COPD) can affect the small airways and alter respiratory mechanics. Nasal high-flow therapy delivers warmed and humidified gas through nasal cannulas and may change airway resistance. Respiratory oscillometry is a noninvasive test that measures respiratory resistance and reactance during quiet breathing.
This prospective, single-center study will enroll 20 adults with severe or very severe stable COPD who have never used nasal high-flow therapy. During a single study visit lasting approximately 6 hours, participants will receive individualized nasal high-flow therapy for 4 hours. Respiratory oscillometry will be measured before exposure, immediately after device titration, and after 30, 60, 120, 180, and 240 minutes.
The primary objective is to describe the time course of the difference between respiratory resistance measured at 5 hertz and at 20 hertz (R5-R20), an indirect index of peripheral airway mechanical abnormalities. Secondary objectives are to describe changes in total and proximal respiratory resistance, respiratory reactance, resonant frequency, and area of reactance. The hypothesis is that nasal high-flow exposure will produce measurable, time-dependent changes in respiratory oscillometry parameters.
NHFlOscillo is a prospective, open-label, single-center, single-arm physiological study involving adults with stable severe to very severe chronic obstructive pulmonary disease (COPD). The study is designed to characterize the time course of respiratory oscillometry parameters during a standardized 4-hour exposure to heated and humidified nasal high-flow therapy.
Participants will attend a single study visit and will be instructed to take their usual medications before the visit. After providing written informed consent, baseline characteristics will be recorded, and participants will complete the modified Medical Research Council Dyspnea Scale (mMRC), the St George's Respiratory Questionnaire (SGRQ), the COPD Assessment Test (CAT), and the Leicester Cough Questionnaire (LCQ). Baseline impulse oscillometry (IOS) will then be performed using a calibrated Vyntus IOS system, with the participant seated and breathing quietly, in accordance with current European Respiratory Society technical standards.
Nasal high-flow therapy will be initiated at a flow rate of 15 L/min and a temperature of 34 °C. After 3 minutes, the temperature will be increased to 37 °C if tolerated; otherwise, it will be maintained at 34 °C. The flow rate will then be increased every 3 minutes to an individualized level consistent with usual clinical practice, up to a maximum of 40 L/min. In participants receiving long-term oxygen therapy, supplemental oxygen will be titrated to maintain an oxygen saturation comparable to that observed under their usual conditions without nasal high-flow therapy.
The exposure will be continued for a total of 4 hours and will be briefly interrupted to perform oscillometry measurements immediately after titration and at 30, 60, 120, 180, and 240 minutes after the start of nasal high-flow therapy.
The target sample size is 20 participants. Changes in oscillometry parameters over time will be analyzed using linear mixed-effects models, with measurement time included as a fixed effect and participant included as a random effect. Each post-exposure time point will be compared with the pre-exposure baseline. Results will be reported as mean differences with 95% confidence intervals and interpreted according to the minimal clinically important difference for each outcome, when available.
Prespecified subgroup analyses will be conducted in participants receiving long-term oxygen therapy and in participants with cough and sputum production. Cough and sputum production will be identified using two alternative operational definitions:
CAT: a score ≥2 on both items 1 and 2; SGRQ: cough on most days or several days per week (response option 1 or 2 to the item "I cough") and sputum production on most days or several days per week (response option 1 or 2 to the item "I bring up sputum").
5,520 studies on the registry are indexed under Pulmonary Disease, Chronic Obstructive; 856 are open to participants now.
This study's planned enrollment of 20 is below the median of 62 across 3,839 interventional studies indexed under Pulmonary Disease, Chronic Obstructive.
Browse Pulmonary Disease, Chronic Obstructive studies →ADIR Association is the lead sponsor of 27 studies on the registry; 7 are open to participants now.
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Non-inclusion Criteria:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive individualized, heated and humidified nasal high-flow therapy (myAirvo 3, Fisher \& Paykel Healthcare, New Zealand) for 4 hours during a single study visit, with repeated respiratory oscillometry assessments.
Device: Heated Humidified Nasal High-Flow Therapy
Therapy is initiated at 15 L/min and 34 °C. After 3 minutes, the temperature is increased to 37 °C if tolerated; otherwise it is returned to or maintained at 34 °C. Flow is increased every 3 minutes to an individualized clinically used level, up to 40 L/min. In participants receiving long-term oxygen therapy, supplemental oxygen is titrated to maintain a saturation comparable to the usual saturation without nasal high-flow therapy. Total exposure duration is 4 hours. The intervention is briefly interrupted for respiratory oscillometry immediately after titration and at 30, 60, 120, 180, and 240 minutes.
Change From Baseline in Frequency Dependence of Respiratory Resistance (R5-R20)
Frequency dependence of respiratory resistance is calculated as respiratory resistance measured at 5 hertz minus respiratory resistance measured at 20 hertz (R5-R20). It is measured by impulse oscillometry using the Vyntus impulse oscillometry system (IOS) and expressed in kilopascals per liter per second (kPa/L/s). Percent-predicted values will also be reported when appropriate reference equations are available. The outcome is the change from the pre-exposure baseline at each post-baseline assessment during the exposure period. The registered measure is the repeated change from the pre-exposure baseline across the exposure period.
Time frame: Baseline; immediately after individualized nasal high-flow titration; and 30, 60, 120, 180, and 240 minutes after starting nasal high-flow therapy.
Change From Baseline in Total Respiratory Resistance at 5 Hertz (R5)
Total respiratory resistance at 5 hertz (R5) is measured by impulse oscillometry and expressed in kPa/L/s. Percentage of predicted values will also be reported when reference equations are available.
Time frame: Baseline; immediately after individualized nasal high-flow titration; and 30, 60, 120, 180, and 240 minutes after starting nasal high-flow therapy.
Change From Baseline in Proximal Respiratory Resistance at 20 Hertz (R20)
Respiratory resistance at 20 hertz (R20), reflecting predominantly proximal airway resistance, is measured by impulse oscillometry and expressed in kPa/L/s. Percentage of predicted values will also be reported when reference equations are available.
Time frame: Baseline; immediately after individualized nasal high-flow titration; and 30, 60, 120, 180, and 240 minutes after starting nasal high-flow therapy.
Change From Baseline in Respiratory Reactance at 5 Hertz (X5)
Respiratory reactance at 5 hertz (X5) is measured by impulse oscillometry and expressed in kPa/L/s. Percentage of predicted values will also be reported when reference equations are available.
Time frame: Baseline; immediately after individualized nasal high-flow titration; and 30, 60, 120, 180, and 240 minutes after starting nasal high-flow therapy.
Change From Baseline in Resonant Frequency (Fres)
Resonant frequency (Fres) is measured by impulse oscillometry and expressed in hertz. Percentage of predicted values will also be reported when reference equations are available.
Time frame: Baseline; immediately after individualized nasal high-flow titration; and 30, 60, 120, 180, and 240 minutes after starting nasal high-flow therapy.
Change From Baseline in Area of Reactance (AX)
Area of reactance (AX) is measured by impulse oscillometry and expressed in kPa/L. Percentage of predicted values will also be reported when reference equations are available.
Time frame: Baseline; immediately after individualized nasal high-flow titration; and 30, 60, 120, 180, and 240 minutes after starting nasal high-flow therapy.
Plan to share: Yes — Data will be made available upon reasonable request for research purposes after publication. This includes de-identified data related to demographic characteristics, as well as endpoints published either in the main manuscript or any supplemental data. Requests should be sent to t.bonnevie@adir-hautenormandie.com
Time frame: Data will be made available after publication.
Access criteria: Data will be made available upon request for research purposes. Requests should be sent to t.bonnevie@adir-hautenormandie.com.
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Pulmonary Disease, Chronic Obstructive →
ADIR Association