Upper Airway Morphology and Physiology During Graded Positive Pressure and Nasal High Flow: An MRI Study

Effects of Graded Positive Airway Pressure and Nasal High Flow Interfaces on Upper Airway Morphology and Breathing Physiology in Healthy Volunteers and COPD Patients: A Controlled MRI Study

Status

Not yet recruiting

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT07886502

Acronym

AIR-MRI

Enrollment

Registered

2026-10-21

Start date

2026-10-01

Completion date

2028-07-01

Last updated

2026-10-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Chronic Obstructive Pulmonary Disease (COPD)

Keywords

COPD, Nasal high flow, Positive airway pressure, Magnetic resonance imaging, Upper airway volume, Upper airway morphology, Breathing physiology

Brief summary

This study investigates the effects of graded nasal high flow (NHF) and continuous positive airway pressure (CPAP) on upper airway morphology and respiratory physiology in healthy volunteers and patients with COPD. Participants undergo baseline MRI and physiological assessment followed by NHF at 30 and 60 L/min and CPAP at 4 and 12 cmH₂O. The primary aim is to determine whether graded NHF and CPAP induce dose-dependent changes in upper airway morphology, including upper airway volume and cross-sectional area, during MRI scans.

Detailed description

Background: Nasal and oronasal masks are the gold standard when applying non-invasive ventilation in chronic hypercapnic respiratory failure, providing effective pressure support and CO2 clearance. Nasal high flow (NHF) offers a less invasive alternative with modest positive pressure, but its effect on upper airway anatomy remain largely unknown. The positive airway pressure can influence airway calibre, dynamics, and upper airway closure, but the effects of nasal high flow (NHF) on upper airway morphology have not been directly investigated by MRI. Aims: This study investigates the effects of NHF at different flow rates compared to continuous positive airway pressure (CPAP) on upper airway morphology and respiratory physiology in healthy volunteers and patients with COPD. The primary aim is to determine whether graded NHF and CPAP induce measurable, dose-dependent changes in upper airway volume and cross-sectional area assessed by MRI. Methods: After baseline MRI and physiological assessment, each participant will undergo repeated measurements under two respiratory support modalities: NHF at 30 and 60 L/min and CPAP at 4 and 12 cmH₂O. The two modalities will be applied in randomized order, while both graded settings within each modality will be assessed. MRI will be used to assess changes in upper airway morphology. Respiratory physiology will be assessed under each condition by measuring tidal volume, respiratory rate, minute ventilation, inspiratory and expiratory times, transcutaneous CO₂, inspiratory effort, and work of breathing.

Interventions

DEVICENasal High Flow

Nasal high flow applied at flow rates of 30 and 60 L/min during MRI and physiological assessment.

DEVICEContinuous Positive Airway Pressure

Continuous positive airway pressure applied at pressure levels of 4 and 12 cmH₂O during MRI and physiological assessment.

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Written informed consent * Age ≥18 years * BMI ≤30 kg/m²

Exclusion criteria

* Inability or refusal to provide informed consent * Contraindications to MRI (e.g., claustrophobia or ferromagnetic implants) * Contraindications to mask-based positive airway pressure or nasal high flow * Pregnancy * Physical or mental conditions limiting study participation or compliance, as judged by the investigator * Alcohol, drug, medication, or other substance abuse * Any other objective reason preventing study participation, as determined by the investigator

Design outcomes

Primary

Measure	Time frame	Description
Retropalatal posterior airway space volume	At baseline and at each NHF and CPAP condition	Change in total retropalatal posterior airway space volume (cm³) from baseline under graded NHF and CPAP conditions, assessed by MRI.

Secondary

Measure	Time frame	Description
Retropalatal upper airway cross-sectional area	At baseline and at each NHF and CPAP condition	Change in retropalatal upper airway cross-sectional area (mm²) from baseline under graded NHF and CPAP conditions, assessed by MRI.

Countries

Germany

Contacts

CONTACTMaik F Schröder

maik.schroeder@klinikumdo.de0049 (0)152 023 985 43

PRINCIPAL_INVESTIGATORGeorg Nilius

Klinikum Dortmund

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Oct 22, 2026