Assessing the effects of personalised airway clearance techniques in children and young people with Primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a rare inherited condition in which mucociliary clearance is impaired from birth. Ineffective mucus clearance poses a risk of repeated infections, inflammation, and bronchiectasis in PCD. As such, physiotherapists advise people with PCD to complete airway clearance techniques (ACT) twice daily at home to facilitate mucus clearance from the lungs. ACT regimens are personalised to the needs of the individual but current tools available clinically to assess the effects of ACT regimens clinically are limited.
In a population of children and young people with PCD, this study aimed to establish how current literature tells us ACT regimens should be personalised, and how they currently are personalised in practice. It also aimed to quantify lung health and short-term response to a personalised ACT regimen (compared to no-ACT) and to understand the circumstances under which personalisation of ACT regimens is altered with the introduction of functional lung imaging. Using a mixed methods approach, this exploratory study has employed cognitive task analysis methods (critical decision method and think aloud problem solving) to make the decision-making of clinicians explicit, and 129Xe ventilation MRI to accurately assess lung health and treatment response.
This research has found that the personalisation of ACT regimens is complex; physiotherapists often encounter and manage uncertainty when personalising regimens. It has confirmed ventilation distribution is heterogeneous in children with PCD, that 129Xe metric VDP is more sensitive to detect ventilation abnormalities than the widely used spirometry metric, FEV1. It has shown that the response to a personalised ACT regimen was varied, with some individuals improving and others worsening immediately post-ACT. It has discovered that functional lung imaging informed ACT regimen modification in most cases, but that in individuals with more severe disease, physiotherapists planned to reassess the individual in light of the MRI data prior to proposing ACT regimen changes. 129Xe MRI can assess change in ventilation distribution following an ACT regimen; as an exploratory study, these findings can inform future research.