Tidal breathing parameters measured using structured light plethysmography in healthy children and those with asthma before and after bronchodilator

摘要

Structured light plethysmography (SLP) is a light‐based, noncontact technique that measures tidal breathing by monitoring displacements of the thoracoabdominal (TA) wall. We used SLP to measure tidal breathing parameters and their within‐subject variability (v) in 30 children aged 7–16 years with asthma and abnormal spirometry (forced expiratory volume in 1 sec [FEV1] <80% predicted) during a routine clinic appointment. As part of standard care, the reversibility of airway obstruction was assessed by repeating spirometry after administration of an inhaled bronchodilator. In this study, SLP was performed before and after bronchodilator administration, and also once in 41 age‐matched controls. In the asthma group, there was a significant increase in spirometry‐assessed mean FEV1 after administration of bronchodilator. Of all measured tidal breathing parameters, the most informative was the inspiratory to expiratory TA displacement ratio (IE50SLP, calculated as TIF50SLP/TEF50SLP, where TIF50SLP is tidal inspiratory TA displacement rate at 50% of inspiratory displacement and style="fixed-case">TEF50 style="fixed-case">SLP is tidal expiratory style="fixed-case">TA displacement rate at 50% of expiratory displacement). Median (m) style="fixed-case">IE50 style="fixed-case">SLP and its variability ( style="fixed-case">vIE50 style="fixed-case">SLP) were both higher in children with asthma (prebronchodilator) compared with healthy children ( style="fixed-case">mIE50 style="fixed-case">SLP: 1.53 vs. 1.22, P < 0.001; style="fixed-case">vIE50 style="fixed-case">SLP: 0.63 vs. 0.47, P < 0.001). After administration of bronchodilators to the asthma group, style="fixed-case">mIE50 style="fixed-case">SLP decreased from 1.53 to 1.45 (P = 0.01) and style="fixed-case">vIE50 style="fixed-case">SLP decreased from 0.63 to 0.60 (P = 0.04). style="fixed-case">SLP‐measured tidal breathing parameters could differentiate between children with and without asthma and indicate a response to bronchodilator.