ABSTRACT
<p><b>OBJECTIVE</b>To investigate the characteristics of tidal breathing pulmonary function in children with tracheobronchomalacia (TBM).</p><p><b>METHODS</b>In this study, 30 children who were diagnosed with TBM using electronic bronchoscopy were enrolled in the observation group; 30 healthy children were recruited in the normal control group. For individuals in each group, the assessment of tidal breath pulmonary function was performed at diagnosis and 3, 6, 9, and 12 months after diagnosis.</p><p><b>RESULTS</b>There were no significant differences in tidal volume, inspiratory time, expiratory time, and inspiratory to expiratory ratio between the two groups (P>0.05). Compared with the control group, the observation group had a significantly higher respiratory rate and significantly lower ratio of time to peak tidal expiratory flow to total expiratory time (TPTEF/TE) and ratio of volume to peak tidal expiratory flow to total expiratory volume (VPTEF/VE). There was a time-dependent increase in TPTEF/TE and VPTEF/VE for TBM children from the time of initial diagnosis to 12 months after diagnosis.</p><p><b>CONCLUSIONS</b>Tidal breathing pulmonary function has characteristic changes in children with TBM. Tidal breathing pulmonary function tends to be recovered with increased age in children with TBM.</p>