Question

In which grade of COPD is the forced expiratory volume (FEV) less than 30%?

a)I
b)II
c)III
d)IV

Answer 1

The forced expiratory volume (FEV) less than 30% is associated with grade IV, or very severe COPD, as determined by spirometry.

Step-by-step explanation:

The grade of Chronic Obstructive Pulmonary Disease (COPD) where the forced expiratory volume (FEV) is less than 30% of the predicted value is grade IV, also known as very severe COPD. This stage is characterized by a very low FEV1 (<30% predicted) or the presence of chronic respiratory failure. Lung volumes are typically measured by a technique called spirometry, in which FEV1, the amount of air that can be forced out of the lungs in one second, and forced vital capacity (FVC), the total amount of air that can be forcibly exhaled, are critically important measurements. The FEV1/FVC ratio is used to diagnose lung diseases, including COPD.