Pulmonary Function Tests

Question 1

What is the difference between volumes and capacities?

Answer 1

Volumes can be measured, while capacities have to be summed from two or more volumes.

Question 2

What are tidal volumes?

Answer 2

Normal inspiratory and expiratory breaths at rest

Question 3

What is expiratory reserve volume?

Answer 3

The amount of air remaining in the lungs after a normal expiration that can be forcefully expired

Question 4

What is inspiratory reserve volume?

Answer 4

The amount of air that can be inhaled after a normal inspiration has taken place

Question 5

Functional residual capacity is ___________.

Answer 5

residual volume plus expiratory reserve volume

Question 6

Inspiratory capacity is ______________.

Answer 6

inspiratory reserve volume plus tidal volume

Question 7

Vital capacity is ________________.

Answer 7

inspiratory reserve volume plus tidal volume plus expiratory reserve volume

Question 8

In terms of spirometry, the hallmark finding of obstructive diseases is ___________.

Answer 8

reduced FEV/FVC ratio

Question 9

__________ diseases cannot be diagnosed with spirometry.

Answer 9

Restrictive

Question 10

The latter 2/3 of expiration is ___________.

Answer 10

effort independent; it is determined by the elastic recoil of the lungs

Question 11

The _______ side of the flow-volume loops is symmetric.

Answer 11

inspiratory

Question 12

TGV is another term for __________.

Answer 12

functional residual capacity (FRC)

Question 13

Name six causes of restrictive lung disease.

Answer 13

(1) pulmonary fibrosis
(2) pulmonary edema
(3) obesity
(4) neuromuscular disorders
(5) interstitial lung disease
(6) pleural disease

Question 14

During resting breathing, _______ requires effort, but _______ happens spontaneously.

Answer 14

inspiration; expiration

Question 15

Residual volume cannot be ________, it must be estimated.

Answer 15

measured

Question 16

____________ represents the volume at which the elastic recoil of the lungs is balanced with the outward force of the chest wall.

Answer 16

Functional residual capacity

Question 17

Inspiratory reserve volume is the volume that can be inspired after ___________.

Answer 17

a resting inspiration

Question 18

The accepted “normal” range for % predicted is ______________.

Answer 18

80% - 120%

Question 19

In a flow-volume loop, obstructive diseases will be ______________.

Answer 19

left-shifted and have a “coving” of the expiratory rate

Question 20

The “flow-volume loop points to the obstruction” only works for __________.

Answer 20

variable obstructions; fixed obstructions (such as tracheal stenosis) are flattened on both sides

Question 21

Helium volume tests are less accurate in those who have ____________.

Answer 21

obstructive diseases with air trapping

Question 22

The only PFT whose predicted value can be >120% and still be considered normal is _________.

Answer 22

residual volume (which can go up to 140% and still be considered normal)

Question 23

TLC and FRC will be low in _________.

Answer 23

restrictive disorders

Question 24

What can decrease DLCO?

Answer 24

Emphysema, anemia, pulmonary edema, pulmonary vascular disease, and interstitial lung disease

Question 25

DLCO corrected with helium volume tests can ___________.

Answer 25

determine if diffusion is appropriate given volume limitations

Question 26

A bronchodilator test is considered positive when __________.

Answer 26

FEV and/or FVC increase by greater than 12%

Question 27

FRC (aka TGV) is determined by _________.

Answer 27

lung compliance and chest-wall compliance

Question 28

A flow-volume loop in a person with restrictive lung disease will also show _________, much like in obstructive disease.

Answer 28

reduced maximum flow (in this case due to increased resistance to air flow)

Question 29

Extra-thoracic variable obstructions include ___________.

Answer 29

laryngeal edema and vocal-cord paralysis

Question 30

Intra-thoracic variable obstructions include _______.

Answer 30

tracheal tumors

Question 31

P(i[max]) measures ___________.

Answer 31

the maximal inspiratory force (against an occluded aperture)

Question 32

What is the metacholine challenge?

Answer 32

Metacholine induces bronchoconstriction. Those with asthma require orders of magnitude less than those without asthma to induce an asthma attack.