The place of physical exercise and bronchodilator drugs in the assessment of the asthmatic child

Abstract

Exercise of one minute's duration produces an increase of ventilatory function in the asthmatic child as measured by the forced expiratory volume test. Exercise of five to 10 minutes' duration produces a decrease of ventilatory function. These effects are considered to be due to bronchodilatation and bronchoconstriction respectively. The action of bronchodilator drugs on these ventilatory effects of exercise has been examined. When bronchodilatation is produced by a drug, a further increase of the F.E.V. follows one minute's exercise. Bronchodilator drugs partly or completely prevent the fall of F.E.V. following five to ten minutes' exercise. The diagnostic and therapeutic implications of these effects of drugs and exercise on ventilation are discussed.