Lung volumes and lung function testing

Question 1

What is lung compliance

Answer 1

Stretchiness

Question 2

What is the lung like at higher pressure

Answer 2

Stiffer, so lower compliance

Question 3

What is the lung like at lower pressure

Answer 3

Less stiff, more compliance

Question 4

What part of the lung is more compliant than the apex

Answer 4

Base

Question 5

What is lung compliance ensued by

Answer 5

Elastic recoil

Question 6

What are some diseases where there is decreased compliance

Answer 6

Pulmonary fibrosis and alveolar oedema

Question 7

When ay there be increased compliance

Answer 7

normal aging lung

Question 8

What is lung compliance dependent on

Answer 8

Thoracic cage

Question 9

For efficient ventilation, what do healthy people have

Answer 9

• High lung compliance

- Low alveolar surface tension due to surfactant (to stop lung collapsing)

Question 10

What do tests of lungs need to test

Answer 10

• Mechanical condition of lungs
• Resistance of airways
• Diffusion acores alveolar membrane

Question 11

What does a spirometer test and what is It dependent on

Answer 11

Lung volumes

-Lung’s elastic properties and the properties of the muscles of the chest wall

Question 12

What is TV

Answer 12

volume of air moving into and out of the lung at rest

Question 13

What is VC

Answer 13

Volume of air moving into and out of the lungs following forceful inhalation and forceful exhalation

Question 14

What can you not measure using a spirometer

Answer 14

How much air is left in your lungs after forceful expiration

Question 15

What is TLC

Answer 15

Tota lung capacity

Question 16

What is FVC

Answer 16

Forced vital capacity -total volume exhaled

Question 17

What should usually be the FVC

Answer 17

> 80% of the air inhaled should be expired out

Question 18

How to measure lung function

Answer 18

Functional residual capacity

Question 19

What is FRC measured using

Answer 19

Helium dilution (because helium is not metabolized) or nitrogen washout

Question 20

Whats the procedure for nitrogen washout

Answer 20

• patient inspires 100% O2
• Expires into the spirometer system
• Procedure repeated until N2 in the lungs is replaced with O2
• FRC calculated from exhaled N2 and estimated alveolar N2

Question 21

What is a restrictive deficit

Answer 21

Lung expansion is compromised- alterations in lung parenchyma, disease of the pleura or chest wall

-Lungs do not full to capacity hence they are less full before expiration

Question 22

What is the FVC like in a restrictive deficit

Answer 22

Reduced

Question 23

What is the FEV 1 like in restrictive deficit

Answer 23

Relatively normal

Question 24

What is the FEV1/FVC like in a restrictive deficit

Answer 24

Normal/increased

Question 25

What is FEV like in an obstructive deficit

Answer 25

reduced

Question 26

What is FVC like in obstructive deficit

Answer 26

Normal

Question 27

What is the FEC1/FVC like in an obstructive deficit

Answer 27

Lower

Question 28

What is another lung function test

Answer 28

Peak expiratory flow rate (PEF)

Question 29

What does the flow-volume curve show

Answer 29

Expiratory flow rate and expiratory volume

Question 30

What is the deep breath in

Answer 30

TLC

Question 31

What is the deep and fast breath out

Answer 31

RV

Question 32

Which part of the flow volume curve is dependent on effort (effort increases flow rate)

Answer 32

TLC-PEF

Question 33

Whichpart of the flow volume curve is independent of effort (effort does not increase flow rate)

Answer 33

PEF-RV

Question 34

How to measure gas transfer

Answer 34

Diffusion conductance

Question 35

How do you measure diffusion conductance

Answer 35

Measure how easily carbon monoxide crosses from alveolar air to blood

Question 36

How is the diffusion conductance test done

Answer 36

- Patient inhales a single breath of carbon monoxide followed by a breath-hold of 10 seconds - Diffusion capacity is calculated from the lung volume and the percentage of CO in the alveoli at the beginning and the en of the 10s breath- hold