DSA - Pulmonary Function Testing

Question 1

For an __________ disease, air has a hard time moving due to problems in the airways. In some cases (i.e., COPD and emphysema) compliance is high (lungs are stretchable).

Answer 1

Obstructive

Question 2

For a _________ disease, the compliance is low and the lungs resist inflation.

Answer 2

Restrictive

Question 3

What is and FEV1/FVC ratio?

Answer 3

Forced Expiratory Volume in 1 second divided by the Forced Vital Capacity

Question 4

What does a low FEV1/FVC ratio indicate?

Answer 4

Obstructive pattern

Question 5

What does a normal FEV1/FVC ratio indicate?

Answer 5

Either a restrictive or normal pattern

Question 6

If the FEV1/FVC is normal, a low FVC value indicates a ________ pattern, while a normal value indicates a ________ pattern.

Answer 6

Restrictive

Normal

Question 7

Pulmonary function tests are not generally indicated in patients without symptoms, and they may be confusing when nonpulmonary diseases that affect the pulmonary system are active. An example is…

Answer 7

Congestive Heart Failure

Question 8

Why are pulmonary function tests typically ordered?

Answer 8

• • To evaluate symptoms and signs of lung disease
• • To assess progression of lung disease
• • To monitor the effectiveness of therapy
• • To evaluate preoperative patients
• • To screen people at risk of pulmonary disease (i.e., smokers)
• • To monitor for potentially toxic effects of certain drugs or chemicals

Question 9

This is the measurement of the air moving in and out of the lungs during various respiratory maneuvers. It allows one to determine how much air can be inhaled and exhaled, and how fast.

Answer 9

Spirometry

Question 10

What are the three most important lung volume and capacity measures?

Answer 10

FVC
FEV1
FEV1/FVC Ratio

Question 11

This is the volume of air forcibly expired from a maximum inspiratory effort in the first second.

Answer 11

FEV1 (Forced Expiratory Volume in 1 second)

Question 12

This is the total volume that can be forcefully expired from a maximum inspiratory effort.

Answer 12

FVC (Forced Vital Capacity)

Question 13

A spirometric maneuver begins with the patient inhaling as deeply as he or she can. Then the patient exhales as long and as forcefully as possible. The amount exhaled in this manner is the…

Answer 13

FVC

Question 14

The forced expiratory volume in 1 second (FEV1) is the amount of air exhaled during the first second of the FVC maneuver. It tends to be lower in diseases that obstruct the airway, such as _________ or ________.

Answer 14

Asthma

Emphysema

Question 15

This is the measure of the ability of the lungs to transfer gas.

Answer 15

Diffusing Capacity

Question 16

Diffusion in the lungs is most efficient when the ________ _______ for gas transfer is high and the blood is readily able to accept the gas being transferred.

Answer 16

Surface Area

Question 17

In what instances are diffusion decreased?

Answer 17

– Conditions that minimize the ability of the blood to accept and bind the gas that is diffusing (i.e., Anemia).

– Conditions that decrease the surface area of the alveolar-capillary membrane (i.e., Emphysema, Pulmonary Embolism).

– Conditions that alter the membrane’s permeability or increase its thickness (i.e., Pulmonary Fibrosis).

Question 18

The gas used to test the diffusing capacity must be more soluble in blood than in lung tissue. Ideally, the amount of gas entering the blood should be limited by the lungs’ ability to transfer it and not by lung perfusion (i.e., the gas must avidly bind to hemoglobin). ________ ________ is the gas used, as it most closely meets those requirements.

Answer 18

Carbon Monoxide

Question 19

Even after one exhales as long and as hard as possible, some air remains in the lungs. This is called the…

Answer 19

Residual Volume

Question 20

The Residual Volume plus the plus the FVC equals the…

Answer 20

Total Lung Capacity (TLC)

Question 21

The Residual Volume, and hence the Total Lung Capacity, cannot be measured by…

Answer 21

Spirometry

Question 22

For obstructive diseases, measurement of the Residual Volume and Total Lung Capacity can demonstrate _______ _______ and ________.

Answer 22

Air Trapping

Hyperinflation

Question 23

For restrictive diseases, the _______ _______ _______ is needed to confirm true restriction and better quantitate the degree of restriction.

Answer 23

Total Lung Capacity

Question 24

Test results are given measured values and as percents of predicted values. The predicted values and lower limits of normal have been determined in population studies of people without physiologic lung impairment. Each patient’s predicted values depend on his or her…

Answer 24

Age
Height
Sex

Question 25

Criteria for acceptability and reproducibility are established by the American Thoracic Society. In general, an _______ maneuver is acceptable if the patient has made a good effort. An effort is considered good when there is a rapid increase in air flow at the start of exhalation.

Answer 25

FVC

Question 26

A complete maneuver requires at least 6 seconds of _________ ending with a plateau in flow (i.e., no further air is being blown out).

Answer 26

Exhalation

Question 27

A flow-time curve and flow-volume loop are usually included with the report to allow one to visualize the rapid rise and the plateau in flow over time and over lung volumes. In a proper _______ maneuver, flow rates should be at their highest near the start of ________ and should decline through the end. This is graphed in the volume-time curve.

Answer 27

FVC

Exhalation

Question 28

Flow rates are highest near the ________ ________ ________ (where the FVC maneuver begins) and they decline until the ________ ________ (where the FVC maneuver ends). This is graphed as the flow-volume loop.

Answer 28

Total Lung Capacity

Residual Volume

Question 29

The test is repeated at least three times. To meet reproducibility criteria, all three FEV1 measurements must be within ________ of each other and all three FVC measurements must be within _______ of each other. The test with the greatest sum of the FEV1 and the FVC is reported.

Answer 29

200 mL

200 mL

Question 30

Spirometry is frequently repeated after giving a _________. If either the FEV1 or the FVC increases by at least 12% and by at least 200 mL from the prior values, then the patient is said to have a significant _________ response.

Answer 30

Bronchodilator

Bronchodilator

Question 31

To quantify the degree of _________, the clinician needs to note the patients FEV1 as a percentage of the predicted FEV1. Similarly, to quantify the degree of _________, one should note either patient’s FVC or the Total Lung Capacity as a percentage of the respective predicted value.

Answer 31

Obstruction

Restriction

Question 32

Explain the flow chart starting with “Is the FEV1/FVC ratio less than the lower limit of normal?” and the answer is NO.

Answer 32

You know it is either a restrictive or normal pattern. The next question you should ask is “Is the FVC less than the lower limit of normal?”

If yes = Restrictive pattern – go on to ask if the total lung capacity is known.

If no = Normal spirometry study

Question 33

Explain the flow chart starting with “Is the FEV1/FVC ratio less than the lower limit of normal?” and the answer is YES.

Answer 33

You know it is an obstructive pattern, and you need to quantitate the obstruction using the FEV1 as a percentage of the predicted value.

The next question you should ask is “Is the FVC less than the lower limit of normal?”

If yes = Ask if we know the total lung capacity.

If no = Pure obstruction