6.1 Lung Function Testing FINISH Flashcards Preview

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Flashcards in 6.1 Lung Function Testing FINISH Deck (29):
1

Name three reasons for pulmonary function tests?

Diagnosis
Patient assessment
Research

2

When in breathing would an extrathoracic abnormality be evident?

Inspiration

3

When in breathing would an intrathoracic abnormality be evident?

Expiration

4

What may cause a variable upper airway obstruction?

Laryngeal polyp

5

What could cause a fixed upper airway obstruction?

Tracheal stenosis

6

What can the tracings produced by spirometry be used to calculate?

Vital capacity
Tidal volume
Flow rate

7

What is a time-volume graph useful for measuring?

Forced vital capacity

8

What is an example of an obstructive disorder?

Asthma
COPD

9

Why is FEV1 decreased in obstructive disorders?

Narrowed airway reduces the speed that air can be breathed out

10

What spirometry results would you expect in obstructive airways?

FVC nearly normal
FEV1 reduced
FEV1/FVC reduced <70%

11

What is an example of a disease that restricts the airways?

Lung fibrosis

12

Why is FVC reduced in restrictive airways?

Because the lungs are stiff so cant be expanded adequately

13

Why is speed normal in restrictive airways?

Because there is no narrowing

14

What spirometry results would you expect in restrictive airways?

Low FVC
Normal FEV1
FEV1/FVC normal or improved >70%

15

What should a flow volume loop show?

Maximum flow occurs early in expiration
Then small airways become narrowed by compression of the lungs
Results in an early fall in expiratory flow rate

16

Why should PEFR be plotted on a chart?

Because it varies according to height and weight

17

Why is there scalloping of curve in an obstructive defect?

Airways collapse on expiration
This dramatically reduces flow

18

What does vital capacity depend on?

Maximal expiration and maximal inspiration

19

What sort of defect is more sensitively revealed by an expiratory flow-volume loop?

Obstructive

20

What would a mild obstruction of the small airways produce on a flow volume curve?

Scalloping

21

What would indicate a severe obstruction on the flow volume curve?

Reduced PEFR

22

How can we measure residual volume?

Helium dilution test

23

How can you measure dead space?

Nitrogen wash out method

24

How can diffusion capacity be estimated?

Carbon monoxide transfer factor

25

What is diffusion conductance?

The resistance to diffusion across the alveolar membrane

26

What is another name for the nitrogen washout technique?

Fowlers method

27

In addition to measuring dead space, what can the nitrogen washout technique be used to assess?

Mixing efficiency within the lungs

28

How is anatomical dead space determined?

By measuring the volume of gas that is in the conducting airways

29

How is the helium dilution test used to calculate residual volume?

Used to measure the functional residual capacity which can then be used to calculate the residual volume