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Flashcards in 2. Pulmonary Function Tests Deck (25):
1

the rate at which the lung deflates (exhales) is a function of what?

resistance, and elastic recoil.

2

elastic recoil is determined by what?

properties of the tissue, and the volume to which it is inflated

3

stiff balloon will empty more or less air in one sec than floppy?

more

4

balloon that is inflated to a higher volume will empty more or less air in one sec than a less-volume balloon?

more

5

low FEV1 comes from what 3 things/

-incr in airway resistance
-decr in recoil
-decr in volume
-any combo of these

6

diseases in which airway resistance is incr

asthma, bronchitis, tracheal tumor, aspiration

7

diseases in which recoil is decr

emphysema

8

diseases in which lung vol decr

restrictive disease

9

in restrictive disease, is the VC incr or decr?

decr

10

in obstructive disease, is the VC incr or decr?

normal or decr

11

how does pulm fibrosis have opposing effects on the FEV1?

elastic recoil incr -> incr FEV1
stiff lungs cannot be inflated very much -> decr FEV1

12

what measure distinguishes between obstructive and restrictive disease?

RATION of FEV1 to FVC.

13

PFTs in obstructive disease

FEV1 decr, FVC normal or decr, ratio decr

14

PFTs in restrictive disease

FEV1 decr, FV decr, ration normal or incr

15

since we can't measure FRC or RV with spirometry, how do we measure them?

plethysmography (like Inyang did?)

16

VC + RV = what?

TLC.

17

what is FRC?

point at which the elastic recoil of lungs exactly balances the recoil of the chest wall

18

what is RV when does it increase?

RV = amt of gas left in lungs after max expiratory effort. incr in obstructive disease (air trapping)

19

what is a restrictive ventilatory defect?

expansion of the lungs is restricted. reduction in TLC. NOT a reduction in VC. caused by insp muscles being unable to fully inflate the lungs and rib cage.

20

examples of restrictive defect?

neuromuscular disease, chest wall problems, pleural disease, loss of lung, interstitial lung disease

21

when is the flow-volume loop most useful?

in dx problems with inspiration, exp extra-thoracic airflow obstruction.

22

what affects the diffusing capacity?

-partial pressure gradient of CO between alveolus and blood.
-total surface area avail for gas exchange
-hemoglobin
-thickness of diffusing surface
-lung vol (if can't take deep breath, DLCO decr)

23

what happens to diff capacity in smokers?

in smokers, there is incr CO in blood, which decr the partial pressure gradient, and decr measured DLCO

24

combination of obstructive pattern and low DLCO suggests what disease?

emphysema

25

combination of restrictive pattern, incr ratio, and low DLCO suggests what disease?

interstitial lung disease