Spirometric response to a bronchodilator. Reference values for healthy children and adolescents.

The spirometric response to inhaled salbutamol was assessed in 492 healthy volunteers 6 to 20 yr of age. Mean and standard deviation of the changes, expressed as percentage of prebronchodilator values, were as follows: forced vital capacity (FVC): 1.7 +/- 2.8; forced expiratory volume in one second (FEV1): 3.3 +/- 3.4; (FEV1/FVC): 3.1 +/- 3.2; peak expiratory flow: 6.4 +/- 8.6; maximal mid-expiratory flow: 10.1 +/- 8.8; maximum expiratory flow at 50% of FVC: 8.8 +/- 9.5 and maximum expiratory flow at 25% of FVC: 14.0 +/- 14.7. The changes were significant (p less than 0.005) for all parameters and similar to those observed in adults.