Question

In patients with a post-bronchodilator FEV1/FVC < 0.70, at what post-bronchodilator FEV1 predicted value is the COPD severity classified as Stage 4 or 'very severe'?

Answer 1

In patients with a post-bronchodilator FEV1/FVC < 0.70, the COPD severity is classified as Stage 4 or 'very severe' when the post-bronchodilator FEV1 predicted value is less than 30% of the predicted normal value.

Step-by-step explanation:

In patients with a post-bronchodilator FEV1/FVC < 0.70, the COPD severity is classified as Stage 4 or 'very severe' when the post-bronchodilator FEV1 predicted value is less than 30% of the predicted normal value.

For example, if the predicted normal value for FEV1 is 2 liters, then the patient would be classified as Stage 4 'very severe' if their post-bronchodilator FEV1 value is less than 0.6 liters (30% of 2 liters).

It is important to note that the predicted normal value for FEV1 can vary depending on factors such as age, sex, height, and ethnicity.