Obstructive Airway Diseases

Question 1

What are the main obstructive airway diseases?

Answer 1

• Chronic bronchitis
• Emphysema
• Asthma

Question 2

Which of the main airway diseases are better known as CODP?

Answer 2

Chronic bronchitis and Emphysema

Question 3

What is FEV1?

Answer 3

Forced expiratory volume of air exiting the lung in the first second of expiration

Question 4

What is FVC?

Answer 4

Forced vital capacity

• Final total amount expired
• FEV1 is usually about 70-80% of FVC.

Question 5

What is Spirometry?

Answer 5

Spirometry is a simple test used to help diagnose and monitor certain lung conditions by measuring how much air you can breathe out in one forced breath.

Question 6

What can PEFR (Peak expiratory flow rate) be used for?

Answer 6

PEFR can be used to demonstrate obstructive lung disease.

Question 7

What occurs in obstructive lung disease?

Answer 7

• There is airflow limitation!
• PEFR is reduced
• FEV1 is reduced!
• FVC may be reduced
• FEV1 is less than 70% of FVC

Question 8

What does bronchial asthma cause?

Answer 8

Type I hypersensitivity in the airways

Question 9

Is bronchial asthma reversible?

Answer 9

YES

Bronchial smooth contraction and inflammation can be modified by drugs or reversed spontaneously.

Question 10

Aetiology of Chronic bronchitis and Emphysema

Answer 10

• Smoking
• Atmospheric pollution
• Occupation: dust
• Effect of age and susceptibility

Question 11

Morphological changes in Chronic bronchitis in the large airways

Answer 11

• Mucous gland hyperplasia
• Goblet cell hyperplasia
• Inflammation and fibrosis is a minor component

Question 12

Morphological changes in Chronic bronchitis in the small airways

Answer 12

• Goblet cells appear

- Inflammation and fibrosis in long standing disease

Question 13

Pathological definition of emphysema

Answer 13

Increase beyond the normal in the size of airspaces distal to the terminal bronchiole arising either from dilatation or from destruction of their walls and without obvious fibrosis.

Question 14

What are the different forms of emphysema?

Answer 14

• CENTRIACINAR
• PANACINAR
• PERIACINAR
• SCAR

Question 15

What is a bulla?

Answer 15

A Bulla is an emphysematous space greater than 1cm.

Question 16

Pathogenesis of emphysema

Answer 16

• Smoking-protease, antiprotease imbalance
• Ageing
• Alpha-1-antitrypsin deficiency

Question 17

Is airway obstruction in COPD reversible or irreversible?

Answer 17

Traditionally airways obstruction in COPD considered IRREVERSIBLE
…but this may not be completely true

Question 18

Can we regrow alveolar walls that have been lost?

Answer 18

NO

Question 19

What is normal PaO2?

Answer 19

10.5 - 13.5 kPa

Question 20

What is normal PaCO2?

Answer 20

4.8 - 6.0 kPa

Question 21

What 4 abnormal states are associated with Hypoxaemia?

Answer 21

• Ventilation/Perfusion imbalance
• Diffusion impairment
• Alveolar Hypoventilation
• Shunt

Question 22

Would you give oxygen to COPD patients?

Answer 22

Yes but only small amount

Question 23

How do large shunts respond to increases in FI blood leaving normal lung?

Answer 23

Large shunts respond poorly to increases in FI O2 Blood leaving normal lung is already 98% saturated

Question 24

How is a decrease in PaO2 due to hypoventilation corrected?

Answer 24

By raising FIO2

FIO2 = the fraction of air inspired which is oxygen

Question 25

Why does Pulmonary Hypertension occur?

Answer 25

• Pulmonary vasoconstriction!
• Pulmonary arterioles
• Loss of capillary bed
• Secondary polycynthaemia