Overview

• The ratio between the forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) is also known as the Tiffeneau-Pinelli index. This ratio is used to assess for the fraction of air that the patient is able to expel in the first second,  and a reduced ratio is a sign of obstruction.

• • Normal Range

  • >0.70
• A reduced FEV₁/FVC ratio (<0.7) is indicative of obstructive pulmonary disease.

• • Causes of Obstructive Disease

  • COPD
  • Asthma
  • Bronchiectasis
  • Cystic fibrosis
  • Bronchiolitis
  • α1-antitripsin deficiency