Obstructive defect on spirometry in a nine-year-old child

Note the reduced FEV₁/FVC and FEV₁ (red boxes) and the scooped curve shape of the green expiratory flow loop (red arrow, above x-axis), consistent with an obstructive defect. The airflow obstruction is reversible.
After treatment with a bronchodilator, there is significant improvement (>10%) in FEV₁ and the FEV₁/FVC ratio also increases (orange boxes). The expiratory flow volume loop (above x-axis) shown in blue is now nearly normal.