Respiratory 14

Question 1

What is lung compliance?

Answer 1

A measure of the elastic properties of the lungs and a measure or how easily the lungs can expand

Question 2

What kind of property Lung Compliance?

Answer 2

A dynamic and static property

Question 3

Why can compliance be a static and dynamic property?

Answer 3

Because it can be measured in the presence and absence of airflow

Question 4

What is lung compliance given by?

Answer 4

The magnitude of the lung volume produced by given change in transpulmonary pressure

Question 5

What is compliance the slope of?

Answer 5

A pressure volume curve

Question 6

What pressure is most important in determining lung volume?

Answer 6

Transpulmonary pressure

Question 7

What does Static Compliance represent?

Answer 7

The lung compliance measured during periods of no gas flow, such as during an inspiratory/expiratory pause

Question 8

When is Static Compliance measured?

Answer 8

During functional residual capacity

Question 9

How is static lung compliance measured?

Answer 9

A patient is asked to make a maximal inspiration and then release a small amount of air. This is when transpulmonary pressure and lung volume is measured. This is repeated at intervals

Question 10

In what disease would a high lung compliance be seen?

Answer 10

Emphysema

Question 11

In what disease would a low lung compliance be seen?

Answer 11

In pulmonary fibrosis

Question 12

What does a stiff lung mean in terms of transpulmonary pressure?

Answer 12

The patient has to make a big effort to expand the chest wall in order to increase transpulmonary pressure that is responsible changing the lung volume

Question 13

What occurs with transpulmonary pressure in people with high compliance lungs?

Answer 13

A small change in transpulmonary pressure will result in big changes in lung volume

Question 14

What is flow determined by when measuring dynamic compliance?

Answer 14

• The difference in pressure between the atmosphere and the alveoli
• Airway resistance against which standing forces have to act

Question 15

When is dynamic compliance measured?

Answer 15

During airflow so either during expiration or inspiration

Question 16

What does Dynamic compliance reflect?

Answer 16

• Lung stiffness

* Airway resistance that may reduce expansion of the lungs

Question 17

Why is Dynamic compliance usually lower or smaller than the static compliance?

Answer 17

Because dynamic compliance takes airway resistance into consideration

Question 18

When does dynamic compliance fall?

Answer 18

When either lung stiffness or airway resistance increases

Question 19

What is FRC?

Answer 19

Functional Residual Capacity and is the capacity of the lungs after normal expiration

Question 20

How is the slope of the curve affected during dynamic compliance and static compliance?

Answer 20

The slope of the curve will be reduced in dynamic compliance and will be increased during static

Question 21

Which airways are collapsed when the lungs are collapsed?

Answer 21

All the medium and small airways

Question 22

What change in transpulmonary pressure opens the lungs?

Answer 22

An increase in transpulmonary pressue

Question 23

What is lung Hysteresis on a collapsed lung?

Answer 23

1) increasing transpulmonary pressure has little effect the airways
2) The first airways open and this is followed by other airways
3) When all the airways are open and the volume increases in a linear fashion
4) when volume reaches its max lung compliance decreases

Question 24

What do changes in pressure and lung volume (lung compliance) look like in a normal healthy patient?

Answer 24

Changes in pressure and volume are minimal

Question 25

What is Hysteresis?

Answer 25

The difference between the inflation and the deflation compliance path

Question 26

Why does Hysteresis exist?

Answer 26

Because you have to use more pressure to open an airway rather than keeping an airway that is already open open