Pulmonary Function Testing

Question 1

Obstructive Lung Disease

1. FEV1/FVC ratio
2. FEV1
3. FVC
4. TLC

Answer 1

1. Decreased
2. Decreased
3. Decreased or NL
4. NL or increased

Question 2

Restrictive Lung Disease

1. FEV1/FVC ratio
2. FEV1
3. FVC
4. TLC

Answer 2

1. Normal
2. Decreased or NL
3. Decreased
4. Decreased

Question 3

List 6 indications for pulmonary function testing (PFT)

Answer 3

1. Eval sign and sx of pulmonary disease (SOB, dyspnea, wheezing)
2. Monitor progress of lung disease
3. Eval the effectiness of a therapy
4. Eval pre-op patients
5. Screen at risk people
6. Monitor toxic effects of toxins and chemicals

Question 4

Pulmonary function tests are not indicated in which patients; may be confusing when what is present?

Answer 4

Ppl w no sx

Person has pulmonary sx d/t a non-pulmonary dz

Question 5

What are the 3 most important values measured during pulmonary function testing?

Answer 5

• FVC
• FEV1
• FEV1/FVC ratio

Question 6

What is the FEV1/FVC ratio used to determine?

Answer 6

Obstructive, Restrictive or NL

Question 7

Which gas is used to assess the diffusion capacity of the lungs?

Answer 7

CO

Question 8

For obstructive disease, measurement of the RV and TLC can be used to demonstrate what?

Answer 8

High RV => air trapping

High TLC => hyperinflation

Question 9

What value is needed to confirm true restriction and to better quantitate the degree of restriction in a restrictive lung disease?

Answer 9

TLC

Question 10

Restrictive Lung Disease

FEV1/FVC is NL.

How can we tell if this patient has a RLD or is normal?

Answer 10

Look at FVC.

If FVC is not less than the lower limit of NL => NL

If FVC is less than NL => RLD

Question 11

In OLD, we can use FEV1 to do what?

Answer 11

Classify the severity of an obstruction

Question 12

Using the FEV1 as % of predicted value for classifying the severity of an obstruction which value indicates mild, moderate, moderately severe, severe, and very severe?

Answer 12

• Mild = >70%
• Moderate = 60-69%
• Moderately severe = 50-59%
• Severe = 35-49%
• Very severe = <35%

Question 13

FVC is LESS than NL.

How can we tell if there is a mixed pattern of obstructive/restrictive (pseudorestriction) or if there is an obstruction with air trapping?

Answer 13

Mixed pattern: decreased TLC

Air trapping: NL or high TLC; very high RV

Question 14

Air trapping will lead to an increase in which value of lung volume?

Answer 14

TLC

Question 15

What are 4 extra-parenchymal causes of restrictive lung disease?

Answer 15

1. Obesity
2. Neuromuscular disease
3. Chest wall deformities
4. Large pleural effusions

Question 16

Which value can be used to distinguish between parenchymal vs. extraparenchymal causes of restrictive lung diseases?

Answer 16

• Diffusing capacity of the lung

- If below lower limit of normal after correcting for lung volumes = parenchymal disease likely