Changes in respiratory function following bronchodilator in acute paediatric asthma measured using structured light plethysmography

Lung function assessment is important in diagnosing and monitoring treatment in asthma. Conventional spirometry requires effort and cooperation of the patient, is challenging in young children and therefore not performed routinely. Structured light plethysmography (SLP) is a non-contact means of assessing lung function that may be useful in such cases. The aim of this study was to assess the use of SLP in determining changes in tidal breathing parameters following treatment with bronchodilator in children with acute asthma. Children admitted to the ward with asthma and on regular bronchodilator treatment were recruited for participation (n=33). Assessment of tidal breathing using a Thora-3Di ™ SLP device was carried out pre- and post-bronchodilator treatment. One-tailed t-tests were used to determine significant changes in tidal breathing parameters determined by SLP. Results showed that the rib-cage versus abdominal contribution to breathing decreased significantly following bronchodilator intervention (46% to 42%, p=0.016) towards the value seen in normative data for the same age group (40%). Other parameters such as respiratory rate, inspiratory time ratio (Ti/Ttot) and ratio of inspiratory to expiratory flow at 50% of tidal movement (IE50) were not significantly affected by bronchodilator treatment. However, variability of Ti/Ttot (as determined by coefficient of variation) did reduce following intervention (0.122 to 0.109, p=0.049). We have shown that SLP can be used in children with acute asthma to acquire objective measures of tidal breathing, and that changes in symmetry such as rib-cage contribution to breathing can be quantified.