Obstructive Airway Diseases

Question 1

Name 3 obstructive airway diseases

Answer 1

Chronic Bronchitis
Emphysema
Asthma

Question 2

Chronic Obstructive Pulmonary Disease (COPD) is the name more commonly known for what diseases?

Answer 2

Chronic Bronchitis

Emphysema

Question 3

What is FEV1?

Answer 3

The forced expiratory volume

Question 4

What is the normal FEVE1 volume?

Answer 4

3.5 - 4 litres

Question 5

What is the normal FVC volume?

Answer 5

About 5 litres

Question 6

What is the normal ratio of FEV1 : FVC?

Answer 6

0.7 - 0.8

Question 7

What is the normal peak expiratory flow rate (PEFR)?

Answer 7

400-600 litres/min

Question 8

What is the normal range of PEFR (as a percentage of best value)?

Answer 8

80-100%

Question 9

What effect do obstructive lung diseases have on:
PEFR
FEV1
FVC

Answer 9

PEFR - reduced
FEV1 - reduced
FVC - may be reduced, may be normal

Question 10

What causes bronchial asthma?

Answer 10

Type I sensitivity in the airways

Question 11

Bronchial asthma is driven by what?

Answer 11

Mast cell degranulation

Question 12

What two groups of chemicals are released due to degranulation?

Answer 12

Chemotactic factors

Spasmogens

Question 13

What does bronchial asthma cause the cross-sectional area of the lumen in small bronchioles to do?

Answer 13

Reduce

Question 14

Is bronchial asthma generally considered to be reversible or irreversible?

Answer 14

Reversible

Question 15

What effect does bronchial asthma have on bronchial smooth muscle?

Answer 15

Bronchial asthma causes contraction and inflammation of the bronchial smooth muscle

Question 16

Give a cause of COPD?

Answer 16

Smoking
Atmospheric pollution
Occupational pollution (e.g. asbestos)
Ageing

(Alpha-1-antiprotease (antitrypsin) deficiency = very rare cause of emphysema)

Question 17

What morphological changes occur in the large airways in chronic bronchitis?

Answer 17

Mucous gland hyperplasia
Goblet cell hyperplasia
inflammation and fibrosis (minor component)

Question 18

What morphological changes occur in the small airways in chronic bronchitis?

Answer 18

Goblet cells appear

Inflammation and fibrosis in long standing disease

Question 19

Emphysema is an increase beyond normal in the size of airspaces distal to the terminal bronchiole arising from

Answer 19

Dilatation
or
destruction of their walls

Question 20

What type of emphysema begins with bronchiolar dilatation followed by loss of alveolar tissue?

Answer 20

Centri-acinar Emphysema

Question 21

What is Panacinar Emphysema characterised by?

Answer 21

Permanent destruction of the entire acinus distal to the respiratory bronchioles
No obvious associated fibrosis

Question 22

What is Bullous Emphysema characterised by?

Answer 22

The presence of one or more abnormally large air spaces surrounded by relatively normal lung tissue

Question 23

What is a Bulla?

Answer 23

An emphysematous space greater than 1cm

Question 24

What is a “bleb”?

Answer 24

An emphysematous space greater than 1cm (a bulla) just underneath the pleura

Question 25

What components of small airways have been found to respond to pharmacological intervention?

Answer 25

Smooth muscle tone | Inflammation

Question 26

What value of PaO2 is seen in type I respiratory failure?

Answer 26

PaO2

Question 27

What is the value of PaCO2 in type I respiratory failure, compared to normal?

Answer 27

Normal or low

Question 28

What is the value of PaCO2 in type II respiratory failure?

Answer 28

PaCO2 > 6.5 kPa

Question 29

What is the value of PaO2 in type II respiratory failure compared to normal?

Answer 29

(usually) low

Question 30

What are the four abnormal states associated with Hypoxaemia?

Answer 30

- Ventilation/Perusion imbalance (V/Q) - Diffusion Impairment - Alveolar Hypoventilation - Shunt

Question 31

What does a ventilation/perfusion mismatch cause which contributes to COPD?

Answer 31

Airway obstruction

Question 32

What does diffusion impairment cause which contributes to COPD?

Answer 32

Loss of alveolar surface area

Question 33

What does alveolar hypoventilation cause which contributes to COPD?

Answer 33

Reduced respiratory drive

Question 34

When does shunt occur in hypoxaemia?

Answer 34

Only during active ineffective exacerbation

Question 35

What is the normal ventilation/perfusion ratio?

Answer 35

4/5 (0.8)

Question 36

What ventilation/perfusion imbalance is the most common cause of hypoxaemia?

Answer 36

Low V/Q

Question 37

Local alveolar hypoventilation due to some focal disease may cause what to arise in some alveoli?

Answer 37

Low V/Q

Question 38

Hypoxaemia due to low V/Q responds well to small increases in what?

Answer 38

FIO2

Question 39

What effect does alveolar ventilation have on PACO2 and PaCO2?

Answer 39

PACO2 - increases | PaCO2 - increases

Question 40

What effect does increased PACO2 have on PAO2 and PaO2?

Answer 40

PAO2 - decreases | PaO2 - decreases

Question 41

A fall in PaO2 due to hypoventilation is corrected by raising what?

Answer 41

FIO2

Question 42

What is FIO2?

Answer 42

The fraction of inspired air which is oxygen

Question 43

What does hypoxia cause in the pulmonary arterioles?

Answer 43

Vasoconstriction

Question 44

Pulmonary arteriolar vasoconstriction can be a localised effect, what would cause all vessels will constrict?

Answer 44

Hypoxaemia

Question 45

Why is vasoconstriction a protective mechanism?

Answer 45

As it stops blood being sent to alveoli that are short of oxygen

Question 46

What is Chronic Cor Pulmonale?

Answer 46

Hypertrophy of the right ventricle resulting from disease affecting the function and/or structure of the lung

Question 47

What factors cause Pulmonary Hypertension to occur in Hypoxic Cor Pulmonale?

Answer 47

- pulmonary vasoconstriction - muscle hypertrophy and intimal fibrosis in pulmonary arterioles - loss of capillary bed - secondary polycythaemia - bronchopulmonary arterial anastamoses