Assessing the effects of personalised airway clearance regimens in young people with Primary Ciliary Dyskinesia.

Background Airway clearance techniques (ACTs) are recommended in Chronic Suppurative Lung Conditions. One such condition is Primary Ciliary Dyskinesia (PCD) which is estimated to affect 5000 people in England.

In PCD impaired mucociliary clearance causes retained mucus and airway obstruction leading to repeated infections, bronchiectasis and ultimately respiratory failure.

To maintain lung health, physiotherapists advise people with PCD to complete a personalised ACT regimen twice daily at home. It is important to ensure ACT regimens are effective, but current methods of assessing the effects of ACTs are limited.

This study will measure the effects of an ACT using Hyperpolarised gas Ventilation magnetic resonance imaging (Ventilation MRI), a highly sensitive tool and Proton MRI, a potentially more widely available tool as a surrogate, to measure lung ventilation. Both types of MRI are radiation free, safe and well tolerated.

Ventilation MRI scans are abnormal in people with PCD even in mild disease.

This study will explore how physiotherapists make decisions about ACT regimen recommendations and if providing physiotherapists with the information from the MRI changes their recommendations. PPI members initially identified research priorities and have been involved throughout this application process.

Research questions What are the short-term effects of personalised ACT regimens on lung health in children and young people with PCD? How do clinicians personalise ACT regimens and is this altered by the introduction of functional imaging? Aims Quantitative: To measure lung health before and after airway clearance (compared to no intervention).

To compare the findings of two outcome metrics of lung ventilation pre and post airway clearance. Mixed methods: To explore how clinicians' make decisions when reviewing and personalising ACT regimens. To investigate how clinical decision-making changes with the introduction of functional imaging of the lungs.

Objectives Quantitative: A controlled before and after study using Ventilation MRI and Proton MRI with an ACT versus no intervention. To assess the correlation and agreement between two types of MRI.

Mixed methods: Cognitive task analysis knowledge elicitation with physiotherapists to produce a concept map An experiment-like task exploring clinicians' critical decision-making at three stages: Watching an ACT regimen review. With the introduction of proton MR images. With the introduction of Ventilation MR images.

The mixed methods components could be undertaken virtually if Covid-19 restrictions are imposed.

Impact and dissemination This research will provide, for the first time, accurate measurements of the short-term effects of ACTs and an understanding of how this information would influence clinical practice. I will produce a knowledge map, which ultimately will be developed into a toolkit to guide ACT personalisation.

It is the first phase of a larger package aiming to optimise the effects of ACTs and maintain long-term lung health.

Subsequent steps will be based on the outcomes of this project and may involve: Other conditions including Cystic Fibrosis and Bronchiectasis. Comparison of imaging guided ACTs with standard ACTs. Assessing longer-term effects of ACTs. Dissemination will target: Clinicians through appropriate posters, articles and presentations.

Patients, families and wider public through a video, social media and at family days.