Inhaled albuterol increases estimated ventilatory capacity in nonasthmatic children without and with obesity

Abstract

Forced mid-expiratory flow (i.e., isoFEF_25-75) may increase with a short-acting β₂-agonist in nonasthmatic children without bronchodilator responsiveness. This could also increase estimated ventilatory capacity along mid-expiration (V̇Ecap_25-75), especially in vulnerable children with obesity who exhibit altered breathing mechanics. We estimated V̇Ecap_25-75 pre- and post-albuterol treatment in 8-12yo children without (n = 28) and with (n = 46) obesity. A two-way ANOVA was performed to determine effects of an inhaled bronchodilator (pre-post) and obesity (group) on isoFEF_25-75 and V̇Ecap_25-75. There was no group by bronchodilator interaction or main group effect on outcome variables. However, a significant main effect of the bronchodilator was detected in spirometry parameters, including a substantial increase in isoFEF_25-75 (17.1 ± 18.0 %) and only a slight (non-clinical) but significant increase in FEV₁ (2.4 ± 4.3 %). V̇Ecap_25-75 significantly increased with albuterol (+11.7 ± 10.6 L/min; +15.8 ± 13.9 %). These findings imply potentially important increases in ventilatory reserve with a bronchodilator in nonasthmatic children without and with obesity, which could potentially influence respiratory function at rest and during exercise.

Keywords: Bronchodilator; FEF(25-75); FEV(1); Forced expiratory flow; Responsiveness; Spirometry.