COPD

Question 1

What is COPD?

Answer 1

Chronic obstructive pulmonary disease is a progressive disease characterised by airflow limitation that is not fully reversible. It consists of two conditions: Chronic Bronchitis and Emphysema.

Question 2

What is chronic bronchitis?

Answer 2

A persistent productive cough on most days for at least 3 months within 2 consecutive years.

Question 3

What is emphysema?

Answer 3

Enlarged air spaces at the acini due to the destruction of the alveolar walls without obvious fibrosis.

Question 4

Pathogenesis of Chronic bronchitis?

Answer 4

Irritants cause hypersecretion of mucus in the airway, which leads to hypertrophy of the mucus gland. This mucus blocks the airway.
Irritants also cause inflammation with CD8+ T cells which further narrows the airway.

Question 5

What are the histological landmarks of CB?

Answer 5

Mucus gland hypertrophy.
Increase in goblet cells.
Loss of ciliated cells.
May get squamous metaplasia.

Question 6

Describe the types of emphysema.

Answer 6

Centriacinar 
 - Proximal part of acinus affected. 
 - More common/severe in upper lobes.
 - Common in smokers.
Panacinar 
 - Uniform dilation/damage. 
 - More common in lower lobes. 
 - Seen in A1AT deficiency
Distal Acinar 
 - Distal part of acinus affected. 
 - Often associated with pneumothorax.

Question 7

Pathogenesis of emphysema?

Answer 7

Neutrophil and macrophage elastases activated by particulates of smoke, causing destruction of alveolar septum/walls.

Therefore, elastin degradation and imperfect repair.

Question 8

What is Bullous emphysema?

Answer 8

A form of emphysema with large subpleural airspaces/ bullae. These may rupture, causing a pneumothorax.

Question 9

What is death in COPD usually due to?

Answer 9

1. Resp acidosis and coma
2. Cor Pulmonale
3. Lung collapse due to pneumothorax.

Question 10

Risk factors for COPD?

Answer 10

Sulphur dioxide 
Occupational dusts: coal, silica, quartz, cadmium, welding fumes. 
Chest infections in 1st year of life. 
Adenovirus 
HIV. 
Smoking 
Biomass fuel burning.

Question 11

What is A1AT deficiency?

Answer 11

A deficiency in the anti-elastase protein A1AT. It counters the release of elastases from neutrophils in the lungs.
A1AT is produced by the liver.

The deficiency is seen in the Pi ZZ phenotype.

Question 12

Symptoms of COPD?

Answer 12

Productive cough 
Wheeze 
Chest-tightness
SOB.
Pleuritic chest pain

Question 13

Signs of COPD?

Answer 13

1. Inspection
   - Central cyanosis
   - Accessory muscles of resp
   - Pursed-lip breathing, prolonged exp, hyperinflation.
2. Breath sounds
   - Decreased
   - Rhonchi/wheeze
   - Prolonged exp.
3. Features of right heart failure.

Question 14

Gold standard of COPD diagnosis?

Answer 14

Spirometry

Question 15

Refer to COPD/ATA1 lecture for more clinical details.

Answer 15

Refer to COPD/ATA1 lecture for more clinical details.