Ch. 16: Pulmonary Function Testing

Question 1

What is the minimum percent increase in expiratory flow following a before-and-after bronchodilator study that indicates significant improvement?

Answer 1

12%

Question 2

Which of the following pulmonary function tests would best determine the patient’s ability to cough?

Answer 2

MIP

Question 3

The volume of air (usually in milliliters) that is inhaled or exhaled during a normal breath

Answer 3

Tidal Volume - VT

Question 4

The maximum volume of air that can be inspired after a normal inspiration.

Answer 4

Inspiratory Reserve Volume - IRV

Question 5

IRV normally is not measured during simple spirometry, but if it is, it should be measured from a _____.

Answer 5

Slow vital capacity

Question 6

IRV normal value

Answer 6

3000 mL

Question 7

Normal VT value

Answer 7

400-700 mL

Question 8

The volume of air exhaled after a normal expiration.

Answer 8

ERV

Question 9

Normal ERV value

Answer 9

1000 mL

Question 10

The volume of air left in the lungs after a maximal expiration.

Answer 10

Residual Volume - RV

Question 11

Normal RV value

Answer 11

1500 mL

Question 12

The amount of air left in the lungs after a normal expiration

Answer 12

FRC

Question 13

When is a closed circuit He dilution test said to be completed?

Answer 13

Once equilibrium is reached

Question 13

Nitrogen washout test

The nitrogen concentration in the lungs is
approximately 79% at the beginning of the test, which is gradually washed out as the patient breathes ________% O2.

Answer 13

100

Question 14

Complete nitrogen washout occurs in about ________.

Answer 14

7 minutes

Question 15

Normal FRC value

Answer 15

2500 mL

Question 16

The maximum amount of air that can be inspired after a normal expiration

Answer 16

Inspiratory Capacity

Question 17

Inspiratory Capacity normal value

Answer 17

3500 mL

Question 18

The technique of plethysmography is based on ____________ law.

Answer 18

Boyle’s

Question 19

What is the most accurate for measuring FRC in COPD patients?

Answer 19

Body box

Question 20

Why may FRC measurements be higher with the body box than those measured by the helium dilution or nitrogen washout method?

Answer 20

Because body plethysmography actually measures the total amount of gas in the thorax

Question 21

Normal FRC value

Answer 21

2500 mL

Question 22

The maximum amount of air that can be exhaled after a maximum inspiration

Answer 22

Vital Capacity

Question 23

What measurement is trying to be obtained?

At the bedside, use a mouthpiece connected to a respirometer. Instruct the patient to inhale as deeply as possible and then slowly and completely exhale through the mouthpiece.

Answer 23

VC

Question 24

Vital Capacity normal value

Answer 24

4500 mL

Question 25

The maximum amount of air that can be exhaled as quickly and forcefully as possible after a maximum inspiration

Answer 25

Forced Vital Capacity

Question 26

The amount of air remaining in the lungs at the end of a maximal inspiration

Answer 26

Total Lung Capacity

Question 27

TLC normal value

Answer 27

6000 mL

Question 28

This is the percentage of the TLC that remains in the lungs after a maximal expiration

Answer 28

RV/TLC ratio

Question 29

Normal RV/TLC value

Answer 29

20-35%

Question 30

The volume of air that is exhaled over a specific time interval during the FVC maneuver.

Answer 30

FEV

Question 31

Because the FEV1 is most commonly measured, look for an FEV1/FVC of less than ____% to indicate an obstructive disease.

Answer 31

70

Question 32

The average flow rate during the middle portion of the FEV.

Answer 32

FEF25%–75%

Question 33

FEF25–75% Normal

Answer 33

4-5 L/sec

Question 34

The maximum flow rate achieved during an FVC.

Answer 34

Peak flow

Question 35

Peak flow normal range

Answer 35

400 to 600 L/min (6.5 to 10 L/s).

Question 36

The maximum volume of air moved into and out of the lungs voluntarily in 10 to 15 seconds.

Answer 36

MVV

Question 37

What measurement tests for overall lung function, ventilatory reserve capacity, and air-trapping?

Answer 37

MVV

Question 38

Normal MVV value

Answer 38

170 L/min ## Footnote may be calculated by using the following formula: 40 x FEV1)

Question 39

________ is displayed on a graph and represents the flow generated during an FVC maneuver followed by a forced inspiratory volume maneuver; both are plotted against volume change.

Answer 39

Flow-Volume Loop

Question 40

What represents the gas exchange capabilities of the lungs?

Answer 40

Diffusion capacity of the lungs (DL)

Question 41

The most common method for measuring DL is the _________.

Answer 41

single-breath method

Question 42

Normal diffusion capacity is approximately ____ mL/min/mm Hg.

Answer 42

25 to 30

Question 43

DLCO is decreased as a result of:

Answer 43

(1) O2 toxicity (2) Emphysema (3) Sarcoidosis (4) Edema (5) Asbestosis

Question 44

# **V/Q SCANNING** For the determination of gas distribution, the patient inhales ________ and holds the breath for 10 to 20 seconds. Radiographs (photoscintigrams) are obtained to observe how the xenon was distributed in the lungs.

Answer 44

radioactive isotope xenon

Question 45

What measurements are decreased in obstructive diseases?

Answer 45

* FEV1 * FEV/FVC * FEF 25-75% * FEF 200-1200

Question 46

What measurements are increased in obstructive diseases?

Answer 46

* FRC * TLC * RV

Question 47

What measurements are decreased in restrictive diseases?

Answer 47

* FRC * FVC * IC * IRV and normal FEV/FVC value

Question 48

# **Severity of obstruction (by interpretation of FEV1)** Mild

Answer 48

70-74%

Question 49

# **Severity of obstruction (by interpretation of FEV1)** Moderate

Answer 49

60-69%

Question 50

# **Severity of obstruction (by interpretation of FEV1)** Moderately severe

Answer 50

50-59%

Question 51

# **Severity of obstruction (by interpretation of FEV1)** Severe

Answer 51

35-49%

Question 52

# **Severity of obstruction (by interpretation of FEV1)** Very severe

Answer 52

<35%

Question 53

Predicted values are determined from what?

Answer 53

* Age * Gender * Height * IBW * Race