Feasibility of home-based oscillometry monitoring in paediatric cystic fibrosis

Abstract

Objectives Oscillometry (OSC) is an effort-independent and highly sensitive technique for detecting changes in peripheral airway function. Home-based monitoring studies in paediatric asthma, have shown utility in detecting changes in disease control and acute pulmonary exacerbations (APEx). Utility in paediatric cystic fibrosis (CF) remains unclear. In this pilot study, we evaluated feasibility, and changes in day-to-day variability of OSC indices within patients commencing elexacaftor/tezacaftor/ivacaftor (ETI). Methods Patients aged 6–11 years due to commence ETI were recruited from the Queensland Children’s Hospital (Australia) CF clinic. Following training and home installation, daily OSC measurements were performed as 30sec triplicate trials (tremoflo-C2, Thorasys, CA) along with a daily respiratory symptom questionnaire. Feasibility, changes in OSC indices (R5, X5 and AX) and day-to-day variabilty (coefficient of variation, COV) were evaluated between baseline (symptom free pre-ETI), APEx or ETI use periods. Results Thirteen patients (7 female, mean ± SD 9.3 ± 2.0 years) completed monitoring for 56 ± 20 (range 29–91) days, including ETI use for 23 ± 8 (9–36) days. Technically acceptable data were achieved on all days tests were attempted (43 ± 15 days per patient). Feasibility was 77% based on total eligible days (554/723) and 80% when omitting days away from equipment (554/699). Eight participants experienced an APEx during the baseline period, with six commencing oral antibiotics. Compared to baseline, OSC indices typically increased during APEx and improved with ETI use, although not reaching statistical significance (p?> 0.05). Conclusion Home-based OSC monitoring had strong feasibility over extended periods in children with CF aged 6–11 years. Results suggest changes in OSC indices and day-to-day variability occur during exacerbation and with introduction of ETI, supporting further studies in larger cohorts to define clinical utility in this setting. [Formula presented]