Pulmonary Function Testing

Question 1

What are some indications for PFTs?

Answer 1

To evaluate sx and signs of lung disease
To assess the progression of lung disease
To monitor the effectiveness of therapy
To evaluate preoperative pts in selected situations
To screen people at risk of pulmonary disease such as smokers or people with occupational exposure to toxic substances in occupational surveys
To monitor for the potentially toxic effects of certain drugs or chemicals

Question 2

When are PFTs not indicated?

Answer 2

For pts without sx

Question 3

What is forced expiratory volume in 1 second (FEV1)?

Answer 3

Amount of air exhaled during the first second of the FVC maneuver

Question 4

What is the normal value for the FEV1/FVC ratio?

Answer 4

Normally 80%

Question 5

What is diffusing capacity?

Answer 5

Assess the body’s ability to take up a gas
Decreased when blood cannot bind gas diffusing (e.g. anemia)
Conditions that reduce surface area for gas exchange (e.g. emphysema, pulmonary embolism)
Conditions that alter membrane permeability or thickness (e.g. fibrosis)

Question 6

Describe what to do when determining obstructive vs restrictive patterns

Answer 6

First determine age, height, sex and demographic data to establish normal values
Verify that tests are valid (timing and effort; repeated 3x)
Administration of bronchodilator (to relax airways in those having smooth muscle spasms (e.g. asthma))

Question 7

Describe an obstructive pattern

Answer 7

Decreased or normal FVC
Decreased FEV1 as well as decreased FEV1/FVC*
Normal or increased total lung capacity

Question 8

Describe a restrictive pattern

Answer 8

Decreased FVC
Decreased or normal FEV1
Normal or elevated FEV1/FVC*
Decreased total lung capacity

Question 9

Look at

Answer 9

Flow charts