- Lung Function Abnormalities in Bronchial Asthma.

Lung Function Abnormalities in Bronchial Asthma.

Spirometry (in clinic):

• Airflow limitation
• Low FEV1 (relative to percentage of predicted norms)
• FEV1:FVC ratio< 0.80

Bronchodilator response (to inhaled β-agonist):
o Improvement in FEV1 ≥12% and ≥200 mL
Exercise challenge: Worsening in FEV1 ≥15%
Daily peak flow or FEV1 monitoring: day to day and/or A.M.-to-P.M .variation ≥20%.

Ibrahim Samaha