Pathology of Restrictive Lung Disease

Question 1

Restrictive Diffuse Interstitial lung disease

Answer 1

• Reduced Lung Compliance = Stiff Lungs
• Low FEV1 & Low FVC but FEV1/FVC normal ratio
• Reduced Gas Transfer (Tco or Kco) = Diffusion abnormality
• Ventilation/Perfusion Imbalance = When small airways affected by pathology

Question 2

Presentation of diffuse lung disease

Answer 2

• Discovery of Abnormal CXR or CT scan
• DYSPNOEA
  ~ Shortness of Breath on exertion
  AS DISEASE PROGRESSES
  ~ Shortness of Breath at rest
• Respiratory Failure – Type 1
• Heart Failure

Question 3

What is DIFFUSE ALVEOLAR DAMAGE associated with?

Answer 3

• Major trauma
• Chemical injury/toxic inhalation
• Circulatory shock
• Drugs
• Infection including viruses (influenza, SARS Cov1 SARS Cov2)
• Auto(immune) disease
• Radiation

Question 4

What is the interstitium of the lung

Answer 4

The connective tissue space around the airways and vessels and the space between the basement membranes of the alveolar walls

Question 5

What is sarcoidosis?

Answer 5

A multisystem granulomatous disorder of unknown aetiology

Question 6

Presentations of Sarcoidosis

Answer 6

1. Young adult
   
   • Acute arthralgia
   • Erythema nodosum
   • Bilateral hilar lymphadenopathy
2. Incidental abnormal CXR or CT scan - no symptoms
3. SOB, cough and abnormal CXR

Question 7

Diagnosis of sarcoidosis

Answer 7

• Clinical findings
• Imaging findings
• Serum Ca++ and ACE
• Biopsy

Question 8

Hypersensitivity pneumonitis: the antigens

Answer 8

• Thermophilic actinomycetes
  
  • Micropolyspora faeni
  • Thermoactinomyces vulgaris
• Bird/Animal proteins - faeces, bloom
• Fungi Aspergillus spp
• Chemicals
• Others

Question 9

Presentation of hypersensitivity pneumonitis

Answer 9

• Acute Presentation
  ~ Fever, dry cough, myalgia,
  ~ Chills 4-9 hours after Ag exposure
  ~ Crackles, tachyopnoea, wheeze
  ~ Precipitating antibody
• Chronic Presentation
  ~ Insidious
  ~ Malaise, SOB, cough
  ~ Low grade illness
  ~ Crackles and some wheeze

Question 10

Where may usual interstitial pneumonitis be seen?

Answer 10

• Connective tissue diseases; esp scleroderma and rheumatoid disease
• Drug reaction
• Post infection
• Industrial exposure - asbestos
• Others!
• Most are idiopathic
  ~ hence Idiopathic Pulmonary Fibrosis (IPF)
  ~ Cryptogenic Fibrosing Alveolitis (CFA)

Question 11

Clinical displays of idiopathic pulmonary fibrosis

Answer 11

• Dyspnoea, Cough,
• Basal Crackles, Cyanosis, Clubbing