Time Course of Respiratory Oscillometry Parameters During Nasal High-Flow Therapy in Stable Chronic Obstructive Pulmonary Disease

ConditionChronic Obstructive Pulmonary Disease (COPD)

Trial statusNot yet recruiting

Trial phaseNot applicable

Trial typeInterventional

Biological sexAll

Age18-85

SponsorADIR Association

About this trial

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.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Age >18 years and <85 years;

Chronic obstructive pulmonary disease classified as Global Initiative for Chronic Obstructive Lung Disease (GOLD) spirometric grade III or IV;

Modified Medical Research Council dyspnea score ≥2;

Completed a pulmonary rehabilitation program at the study center;

Disqualifiers

None

Trial design

Design model

Single group

Treatments tested in this trial

Heated Humidified Nasal High-Flow Therapy
Device
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.

Treatment groups

20 Participants

are divided into 1 treatment group

Group A: Nasal High-Flow TherapyExperimental treatment 1 intervention

Trial outcomes

Primary outcomes

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