Tidal breathing analysis and response to salbutamol in awake young children with and without asthma

Abstract

T Ti id da al l b br re ea at th hi in ng g a an na al ly ys si is s a an nd d r re es sp po on ns se e t to o s sa al lb bu ut ta am mo ol l i in n a aw wa ak ke e y yo ou un ng g c ch hi il ld dr re en n w wi it th h a an nd d w wi it th ho ou ut t a as st th hm ma a ABSTRACT: The purpose of the present study was to investigate: 1) whether tidal flow patterns can be used to discriminate between children with asthma and those without respiratory illness; and 2) whether reversibility to salbutamol in young children can be detected by tidal breathing analysis? Lung function was measured by tidal flow-volume loops (SensorMedics 2600) in 26 awake young children (13 males) with asthma (aged 7-85 months; mean age 33 months), and 26 (13 males) (aged 3-72 months; mean age 34 months) without respiratory illness, before and 15 min after inhalation of nebulized salbutamol, 0.05 mg·kg -1 .The ratios of the time and volume until peak expiratory flow to the total expiratory time and volume, respectively, (TPEF/TE and VPEF/VE), and the ratio of tidal expiratory flow at 25% remaining expiration to peak expiratory flow, TEF 25 /PEF, were significantly lower in asthmatic children than in controls, and increased significantly after salbutamol inhalation in the former. Conversely, TPEF/TE and VPEF/VE, but not TEF 25 /PEF decreased significantly in the controls after salbutamol inhalation. Respiratory rate and expiratory volume·kg -1 body weight did not differ significantly between the two groups before and after salbutamol inhalation.We conclude that tidal breathing analysis can discriminate young children with asthma from children without respiratory illness, both regarding baseline lung function and reversibility to salbutamol.

Effect of inhaled steroids on lung function in young children: a cohort study

“…It is not known if there are other studies in young children addressing this issue. However, both groups of rBO children had a significantly larger positive response to bronchodilator than the controls, which is supported by previous studies [13][14][15][16][17].…”

“…This observation strengthens the likelihood that these lung function measurements reflect severity of OAD in young children, as has been previously reported [13,26]. Furthermore, it appears that the children who subsequently received ICS treatment had the greatest improvement in lung function by 2 yrs of age.…”

“…In large epidemiological studies, it is beneficial to employ lung function measurements that can be easily performed with minimal discomfort and cooperation by the child. In line with these arguments, the shapes of tidal flow/volume (TFV) loops represented by the ratio of time to peak expiratory flow/total expiratory time (tPTEF/tE) are reported to reflect OAD in adults [12], and children [13][14][15][16][17], and additionally predict wheeze in children v3 yrs old [16,17]. Thus, such measures could be used to assess possible effects of ICS treatment on the development of lung function in children with recurrent bronchial obstruction (rBO).…”

“…The loops were selected from tidal breaths with as stable volume and shape of the loops as possible, and the respiratory rate as low as possible. Details of tPTEF/tE ratio calculations have been described elsewhere [13,19].…”

“…Bronchodilator responsiveness was assessed by TFV measurement immediately before and 15 min after inhaled nebulised salbutamol (0.05 mg?kg -1 bodyweight) as previously described in detail [13].…”