Respiratory & Sleep Medicine _ Chronic Lung Disease

Question 1

What are pulmonary function tests?

Answer 1

• Pulmonary function testing (PFT) is a relatively simple battery of tests that quantify lung function in a reproducible manner.
• PFTs are used to diagnose and monitor a wide variety of pulmonary signs, symptoms and diseases.

Question 2

What is the most widely used component of pulmonary function testing?

Answer 2

• Spirometry

Question 3

What is forced expiratory volume in one second (FEV 1 )?

Answer 3

• It is a dynamic spirometric test which evaluates the mechanical properties of the large- and medium-sized airways.
• FEV 1 is a measure of the air volume a person forcefully expires in the first second of expiration following maximal inspiration.

Question 4

What is forced vital capacity (FVC)?

Answer 4

• It is a static spirometric test measuring the total air volume a person can expire after inhaling maximally

Question 5

How is FVC related to total lung capacity ?

Answer 5

• Decreased FVC is usually due to reduced lung capacity (in a restrictive process).
• However, FVC is not equivalent or even necessarily proportional to total lung capacity.
• Reduced airflow, air trapping, and/or increased residual volume decrease FVC in obstructive processes.

Question 6

How are the normal FEV 1 and FVC reference values established?

Answer 6

• Normal values are based on population studies according to gender, age, height, and race.
• Patient’s FEV 1 and FVC can be expressed as either absolute numbers or as a percent predicted of normal (patient’s value divided by average population value).

Question 7

What percent of predicted is considered normal FEV 1 and FVC?

Answer 7

• 80%-100%

Question 8

FEV 1 normally equals about what percent of FVC?

Answer 8

• The normal FEV 1 /FVC ratio changes with age

Question 9

FEV 1 , FVC, FEV 1 /FVC in Obstructive Lung Disease

Answer 9

Question 10

FEV 1 , FVC, FEV 1 /FVC in Restrictive lung disease

Answer 10

Question 11

Why do some restrictive disease have a normal or high FEV1 /FBC ?

Answer 11

• Both FEV 1 and FVC are low.
• If they are proportionately low, the FEV 1 /FVC ratio is normal.
• If FVC is disproportionately low, the ratio is high.

Question 12

What are the two most common obstructive lung disease?

Answer 12

• Asthma and chronic obstructive pulmonary disease (COPD)

Question 13

Causes of Restrictive Lung disease.

Answer 13

• Kyphosis
• Idiopathic pulmonary fibrosis
• Asbestosis
• Sarcoidosis
• Berylliosis
• Beryllium disease
• Neuromascular disease

Question 14

Causes of Obstructive Lung Disease

Answer 14

• Asthma
• COPD
• Bronchiectasis
• Cystic Fibrosis

Question 15

What genetic (autosomal recessive) disease causes pancreatic insufficiency and frequent pulmonary infectious secondary to mucus plugs?

Answer 15

• Cystic fibrosis

Question 16

What is bronchiectasis?

Answer 16

• Permanent dilation and destruction of bronchi usually caused by frequent severe infections and/or inflammation