Benign respiratory pathology

Question 1

Asthma definition

Answer 1

Chronic inflammatory disorder of the airways, with paroxysmal bronchospasm causing: wheeze, cough, variable bronchoconstriction that is at least partially reversible

Question 2

Asthma epidemiology

Answer 2

• Extrinsic (atopic)
• Children and young adults = 33.9% children with wheeze (1 in 10 UK children diagnosed asthma)
• Adults = 9-15% occupational cause - commonest occupational lung disease

Question 3

Asthma pathogenesis

Answer 3

• Mucosal inflammation and oedema
• Mucus plugs in bronchi
• Hyperinflated lungs

Question 4

Atopic asthma

Answer 4

• Type 1 hypersensitivity reaction
• Caused by allergen
• Can cause centrilobular emphysema when exacerbated
• Mucous lands hyperplasia
• Bronchiolar wall smooth muscle hypertrophy

Question 5

COPD definition

Answer 5

two distinct pathological entities

Question 6

Chronic bronchitis =

Answer 6

Cough with sputum for 3 months in 2 consecutive years

Question 7

Emphysema =

Answer 7

caused by chronic bronchitis - abnormal enlargement of alveolar airspaces

Question 8

COPD epidemiology

Answer 8

• Smokers

- 1 in 20 of >65yrs consult GP per year

Question 9

Bronchitis pathogenesis

Answer 9

• Cell damage = inflammation = scar, mucus, infection
• Bronchiole wall thickened or lumen blocked/damaged
• Mucus gland hyperplasia

Question 10

Emphysema pathogenesis

Answer 10

• Increased elastase causes alveolar wall loss and decreased contractility = decreased gas exchange

Question 11

Classification of emphysema

Answer 11

• Centrilobular (centiacinar) – most associated with smoking and coal dust
• Panlobular (panacinar) - severest lower lobe bases
• Paraseptal (distal acinar) – can rupture pneumothorax

Question 12

Key clinical features of COPD

Answer 12

• Dyspnoea
• Cough: mucus and irritation of lining
• Sputum: hyperproduction of mucus
• Infection
• Right heart signs: increased workload as increased resistance pulmonary HTN and right ventricular hypertrophy

Question 13

Bronchiectasis definition

Answer 13

• Permanent dilation of bronchi and bronchioles caused by destruction of the muscle and elastic tissue (usually with inflammation)

Question 14

Bronchiectasis pathogenesis

Answer 14

bronchiole damage due to infection or autoimmune conditions = inflammation = wall pulled open by adjacent scar/collapse

• Scars cause a major abscess complication
• Bronchiole wall thickened but lumen dilated

Question 15

Aetiology of Bronchiectasis

Answer 15

• Cystic fibrosis,
• Primary ciliary dyskinesia,
• Kartagener syndrome
• Bronchial obstruction (tumour, foreign body)

Question 16

Key clinical features of Bronchiectasis

Answer 16

• Cough, fever, copious foul smelling and yellow/green sputum, abscesses
• Complications = pneumonia, septicaemia, metastatic infection, amyloid (deposits of amyloid in lungs)

Question 17

Interstitial Lung Disease (ILD) definition

Answer 17

group of diffuse and chronic diseases of pulmonary connective tissue – may affect alveolar walls/air spaces and bronchioles

Question 18

ILD pathogenesis

Answer 18

• Trigger causes inflammation and fibrosis in bronchioles

- Leads to thickening = decreased lung compliance

Question 19

Key clinical features of acute ILD

Answer 19

• Damage to lung parenchyma causing acute respiratory distress syndrome = respiratory alkalosis

Question 20

Key clinical features of chronic ILD

Answer 20

• Can affect a lot of alveolar tissue before symptoms arise (dyspnoea increasing for months to years), clubbing, fine crackles, dry cough.
• End stages = honeycomb lung

Question 21

Cystic fibrosis definition

Answer 21

• Inherited multiorgan disorder of epithelial cells affecting fluid secretion in exocrine glands and the epithelial lining of the respiratory, GI and reproductive organs.

Question 22

Cystic fibrosis epidemiology

Answer 22

• Mostly Caucasians; common: 1/25 carrier

Question 23

Cystic fibrosis aetiology

Answer 23

• Mutation in CFTR gene on chromosome 7

Question 24

Cystic fibrosis pathogenesis

Answer 24

• defective CFTR protein means chloride ions can’t be transported out of cells
• Water can’t follow so mucous becomes sticky and causes bronchioles to become blocked
• Hyperplasia of mucus secreting glands, severe chronic bronchitis and bronchiectasis, atrophy and fibrosis of exocrine ducts

Question 25

Key clinical features of CF

Answer 25

- Pancreatic problems = atrophy + fibrosis - GI problems = meconium ileus - Liver problems = plugging of bile canalucili = cirrhosis - 95% of males are infertile

Question 26

Treatment of CF

Answer 26

- 41 years median survival in UK – physio, mucolytics, transplants, vitamins