A new paediatric airway model for in silico evaluation of regional aerosol deposition
Kineshta Pillay1, Warren H. Finlay1 & Andrew R. Martin1
1Aerosol Research Lab of Alberta, University of Alberta, 116 St&85 Ave, Edmonton, T6G 2R3, Canada
Summary
While there has been significant investigation into regional deposition of inhaled drugs in the airways of adults, less is known about where aerosols deposit in children’s lungs. As there are challenges related to performing in vivo deposition measurements using radiolabelled particles in children, other methodologies are needed. To this end, computational models were developed to represent the lungs of girls and boys aged 8, 10 and 12 years. The models were symmetric and followed a single-path numerical approach to calculate aerosol deposition in the airways. Total deposition efficiency calculated by these models was validated against existing in vivo data for children performing controlled breathing patterns and showed agreement for particles ranging from 1 – 3 μm. Regional deposition estimates were further provided for particle deposition in children performing age-adjusted tidal breathing manoeuvres. Differences in deposition between boys and girls were minimal, while age showed a moderate influence. Extrathoracic deposition increased with particle size, while tracheobronchial and alveolar deposition increased initially before peaking between 3 – 5 microns and decreasing thereafter. Comparison against existing regional deposition data from adults showed similar deposition patterns in the central and peripheral airways of adults and children, with lower deposition in these regions in children. It is anticipated that improved understanding of regional deposition in paediatric airways will assist in optimizing regional drug delivery to children in future work.