PFTs

Question 1

What does spirometry measure?

Answer 1

FEV1 and FVC

Question 2

What is required of the patient for spirometry to be effective?

Answer 2

patient needs to make a maximal inspiratory and expiratory effort

Question 3

T/F As we age, the lungs lose their natural elasticity translating to smaller lung volumes and capacities

Answer 3

True

Question 4

T/F When males and females are matched for height and weight, their lung sizes are equal

Answer 4

False. Males still have larger lungs than females even when matched for height and weight

Question 5

How does obesity effect PFTs?

Answer 5

the abdominal mass prevents the diaphragm from descending as far as it could and the PFT results will demonstrate a smaller measured PFT outcome than expected

Question 6

Why can’t TLC be measured by spirometry?

Answer 6

TLC = FVC + RV so it can’t be measured by spirometry because air remains in the lungs at the end of a maximal exhalation - i.e. the RV

Question 7

Which of the following are ways to measure TLC: spirometry, helium dilution, nitrogen washout, body plethysmography, CXR/HRCT?

Answer 7

everything except spirometry. Body plethysmography is the gold standard

Question 8

What percentage is the FEV1 of the FVC?

Answer 8

FEV1 is 75% of the FVC

Question 9

Define FEF (Forced expiratory flow)?

Answer 9

the average forced expiratory flow during the mid (25 - 75%) portion of the FVC

Question 10

Which test is a sensitive test for early obstructive disease?

Answer 10

FEF

Question 11

Define PEFR (Peak expiratory flow rate)

Answer 11

measure of the highest expiratory flow rate during the PFT test

Question 12

What is a useful test to see if treatment is improving obstructive disease?

Answer 12

PEFR

Question 13

What values of FVC and FEV1 are considered in the normal range?

Answer 13

values that are > 80% of predicted based on age, height/size, gender, race

Question 14

PFT results for obstructive airway disease

Answer 14

the FEV1 is reduced disproportionately more than the FVC, resulting in an FEV1/FVC ratio less than 70-80%.

Question 15

What patient populations cannot have a bronchoprovocation test?

Answer 15

unstable cardiac dz, MI or stroke in last 3 months, uncontrolled HTN, pregnancy/nursing, bronchospasm already present

Question 16

What qualifies as a positive bronchoprovocation test?

Answer 16

decrease of 20% in FEV1

Question 17

What is used to determine if there is reversible airway obstruction?

Answer 17

Pre- and post- bronchodilator spirometry

Question 18

PFT results for restrictive lung disease

Answer 18

both the FEV1 and FVC are reduced proportionately. presents with a normal or increased FEV1/FVC ratio

Question 19

If a patient has a low FVC, how do you determine if their disease is restrictive or obstructive?

Answer 19

repeat the test after inhaling a bronchodilator. Improved FVC suggests obstructive pathology. If the FVC remains the same, it suggests restrictive pathology

Question 20

Classification of mild, moderate, severe lung disease

Answer 20

Mild Disease: 65-85% of predicted values. Moderate Disease: 50-65 % of predicted values. Severe Disease: < 50 % of predicted values

Question 21

What is a useful test to determine how well gases diffuse through the alveoli?

Answer 21

Diffusion capacity (DLCO)

Question 22

T/F smoking substantially lowers the DLCO

Answer 22

True

Question 23

Why is CO the preferred agent for DLCO tests?

Answer 23

normally not present in alveoli, transfer is diffusion limited rather than perfusion limited, avidly binds Hb, and its diffusion is less affected by other factors

Question 24

What test is used to determine a patient’s functional aerobic excercise capacity?

Answer 24

VO2 testing.