A Randomised Feasibility Study of CPAP in Large Airway Collapse (RE-LACS)

Large airway collapse (LAC) is an increasingly recognised condition characterised by either bowing of the posterior membrane/trachealis muscle into the trachea or main bronchi (also known as excessive dynamic airway collapse, EDAC) or weakening of the tracheal cartilage (also known as tracheobronchomalacia, TBM).(1-3) LAC often co-exists with other chronic airway conditions, such as asthma or chronic obstructive pulmonary disease (COPD) and is frequently misdiagnosed or overlooked as symptoms, such as shortness of breath, cough and wheeze overlap with other respiratory disease.(1) There is no standardised treatment pathway for patients diagnosed with LAC and current treatment options are limited to physiotherapy and/or hypertonic saline.(3) Exacerbations of LAC, defined as an acute worsening of respiratory symptoms, typically reduce health-related quality of life and increase healthcare utilisation.(4) Small studies and case series have suggested continuous positive airway pressure (CPAP) as a potential treatment for LAC to reduce exacerbations and improve quality of life.(5,6) It is hypothesised CPAP may work as a pneumatic splint helping to prevent dynamic collapse of the large airways. This may increase lung volumes due to increase in flow at functional residual capacity (FRC) and support higher elastic recoil and increased expiratory flow. Additionally, splinting of the large airways may cause stiffening of the large airways, resulting in less resistance and turbulence during expiration and may support sputum expectoration.(3) There is a need for high quality randomised controlled trial (RCT) evidence to inform clinical recommendations in the United Kingdom (UK), as well as globally. Prior to this there is a need for further work exploring the feasibility of performing a large RCT and understanding the acceptability of CPAP as a future treatment for LAC.

Aim To conduct a randomised feasibility study that will provide data to confirm if a larger randomised trial of CPAP in patients diagnosed with LAC is viable

Study Overview

• Status: Not yet recruiting
• Conditions: Asthma; Large Airway Collapse
• Intervention / Treatment: Device: CPAP

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Rebecca Nightingale Dr Nightingale, PhD; Phone Number: +441517053100; Email: rebecca.nightingale@lstmed.ac.uk
• Study Contact Backup: Name: Rachel Burton Dr Burton, MD; Phone Number: +441517053100; Email: rachel.burton@lstmed.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria

1. Adult (≥18 years) at visit 1
2. Able to provide informed consent
3. Prior confirmation of LAC (diagnosed either radiographically or with bronchoscopy)
4. Respiratory co-morbidities optimised
5. ≥1 course of antibiotics and/or prednisolone for an exacerbation of chronic airway disease in the preceding 12 months before visit 1.

Exclusion Criteria

1. Contraindication to CPAP as per British Thoracic Society (BTS) guidelines
2. Already using domiciliary CPAP (including privately purchased)
3. Known obstructive sleep apnoea syndrome (OSAS) eligible for CPAP
4. Suspected OSAS that is awaiting further investigation
5. Pregnant or planning a pregnancy in the next 12 months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Standard of Care; Standard of care for LACS. Which includes physio and good asthma management
Experimental: Intervention (CPAP); Nocturnal CPAP	Device: CPAP; Nocturnal CPAP

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient acceptability	All participants will be asked to complete a questionnaire, which will give us information about their diagnosis pathway, current health and wellbeing related to LAC and other information about treatment options.; Participation in an audio-recorded semi-structured interview will be offered to participants in both arms, to facilitate the collection of more detailed insights surrounding LAC as a condition, diagnosis pathway, treatments (including CPAP). Interview topic guides will be co-produced with the patient and public involvement (PPI) lead. Interviews will be scheduled at the patient's convenience on or after visit 3 (6 months) and will be conducted face-to-face, virtually or by telephone. We will aim to interview up to 10 participants in each arm, or until data saturation is reached. Interviews will be recorded using industry standard recording device/Dictaphone, transcribed, and data analysed under the guidance of the qualitative lead.	From Enrolment until 1 year
Recruitment and Retention	The site will be asked to keep a screening log of all patients identified, approached and given an information leaflet. The number of participants enrolled (defined as a participant providing written informed consent) and the proportion randomised will be reported. Reasons for screen failure and withdrawal will be collected and summarised in the CRF. Recruitment and retention will be periodically assessed in line with agreed targets with the funder.	At 18 months post enrolment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Health Related Quality of Life Assessment	The SGRQ is a 50-item questionnaire used to assess the health and wellbeing of patients with chronic respiratory disease. The questionnaire is composed of 2 parts: part 1 measures symptom burden and part 2 ascertains the impact of their disease on a range of activities that encompass social function, psychological disturbance and physical ability. Scores range from 0 to 100 with a higher score indicating more limitations. The SGRQ will be administered at all on-site visits. A total score will be collected to analyse participant trajectories over the duration of the study and conduct comparative analyses between study arms, considering minimally important clinical differences.	At enrolment and 18 months
Healthcare Resource Utilisation	Primary care (General Practitioner (GP), nurse, other); Secondary care (respiratory, non-respiratory, consultant, nurse, or other), community service (pharmacist, other); Emergency department attendance (respiratory or non-respiratory); Inpatient admission (elective, emergency), admission duration	At 18 months post enrolment

Collaborators and Investigators

• Sponsor: Liverpool School of Tropical Medicine
• Collaborators: Royal Liverpool University Hospital, Liverpool, UK

Study record dates

Study Major Dates

• Study Start (Estimated): April 20, 2026
• Primary Completion (Estimated): June 1, 2028
• Study Completion (Estimated): September 1, 2028

Study Registration Dates

• First Submitted: February 18, 2026
• First Submitted That Met QC Criteria: March 26, 2026
• First Posted (Actual): April 1, 2026

Study Record Updates

• Last Update Posted (Actual): April 1, 2026
• Last Update Submitted That Met QC Criteria: March 26, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Asthma; CPAP; Large Airways Collapse
• Additional Relevant MeSH Terms: Immune System Diseases; Respiratory Tract Diseases; Lung Diseases; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Asthma
• Other Study ID Numbers: 342137

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No