Bronchodilator responsiveness in wheezy infants predicts continued early childhood respiratory morbidity

Objective: Spirometry including bronchodilator responsiveness is considered routine in the workup of asthma in older children. However, in wheezy infants the existence of bronchodilator responsiveness and its prognostic significance remain unclear. Methods: Infants (maxFRC) was measured before and 20 minutes after salbutamol administration. Only infants with an obstructive profile (V̇maxFRC maxFRC measurements. Follow-up data was gathered after a mean of 2 years. Measurements and Main Results: Sixty infants were included in the study of which 32 (53%) demonstrated responsiveness to bronchodilators. The infants in the responsive group had a significantly higher frequency of physician visits for wheezing than the non-responders (3.0 mean visits/yr vs. 1.5 respectively, P = 0.03), and had a higher likelihood of having received asthma medication in the last year of the follow-up period (84% vs. 50% respectively, RR: 1.68[1.10–2.56]). At the end of the follow-up period, more parents in the responsive group reported continued respiratory disease (71% vs. 22%, RR:3.21[1.30–7.95]). Conclusions: Bronchodilator responsiveness can be demonstrated by infant PFT in infants with recurrent wheezing and can predict increased respiratory morbidity until 3 years of age.