Lung Function Testing

Question 1

What does FEV1 mean?

Answer 1

Forced volume of expired air in the first 1 second of maximal expiration

Question 2

What does FVC?

Answer 2

Forced vital capacity - the volume of air that can be expelled from the point of max inspiration to point of max expiration

Question 3

What is the FEV1/FVC ratio?

Answer 3

Ratio is key to determining a restrictive vs obstructive pattern of respiratory disease

Question 4

What is DLco?

Answer 4

Diffusing capacity of CO due to its high affinity to RBC it is used to assess gaseous transfer

Question 5

What type of condition would give a low DLco?

Answer 5

Conditions impairing alveolar surface e.g. Fibrosis

Question 6

What conditions would give a high DLco?

Answer 6

Conditions increasing pulmonary blood flow. E.g. Alveolar haemorrhage

Question 7

What is minute ventilation?

Answer 7

Volume of air inhaled or exhaled per minute

Question 8

What is minute ventilation proportional to? Give example

Answer 8

Blood C02 levels. High minute ventilation gives low blood Co2 levels

Question 9

What would an obstructive picture show?

Answer 9

Reduced FEV1 and unchanged FVC.

Ratio reduced

Question 10

What would a restrictive picture show?

Answer 10

Both FEV1 and FVC reduction

Ratio is the same or reduced

Question 11

Give example of condition where the there would be a mixed restrictive and obstructive picture?

Answer 11

COPD