Idiopathic Pulmonary Fibrosis

Question 1

Definition of idiopathic pulmonary fibrosis

Answer 1

Chronic inflammatory condition of the lung that results in fibrosis of the alveoli and interstitium.
• Manifests over several years and has an unknown cause
• Form of fibrotic lung disease

Question 2

Aetiology and risk factors of pulmonary fibrosis

Answer 2

• Unknown cause
• Risk factors:
• Smoking
• Occupational exposure to organic or metal dust
• GORD
• Infection
• Age
• Male sex
• Family history

Question 3

Pathophysiology of pulmonary fibrosis

Answer 3

• The triggering injury results in a pro-inflammatory and pro-fibrotic response that includes the reflux of macrophages, fibroblasts etc
• There would be progressive fibrosis, formation of fibroblastic foci and deposition of ECM proteins by the fibroblasts
• There would hence be a decline in pulmonary function, there may also be intermittent acute deteriorations

Question 4

History and Examination

Answer 4

• Exertional dyspnoea: Usually the most prominent and disabling symptom. Progressive symptom
• Cough: typically non-productive
• Crackles: End-inspiratory, basilar crackles are usually present (dry and Velcro like)
• Malaise
• Weight loss
• Arthralgia
• Clubbing

Question 5

Investigations for pulmonary fibrosis

Answer 5

• ABG: check for hypoxia or respiratory failure
• CXR: may show ground glass shadowing, may see basilar, bilateral opacities
• High resolution CT: more sensitive and diagnostic for PF. Can see HONEYCOMBING
• Anti-nuclear antibodies: may be elevated in some patients
• Pulmonary function test: Spirometry would have RESTRICTIVE results

Question 6

Treatment for pulmonary fibrosis

Answer 6

Acute exacerbation:
1) Admission to hospital + High-dose corticosteroid: may require mechanical ventilation or lung transplant. Prednisolone may help with exacerbation

All patients not experiencing acute exacerbation:
1) Antifibrotic therapy: Treatment with Pirfenidone

+ Smoking cessation + Pulmonary rehab +- Oxygen: Pulmonary rehab to improve functional status and quality of life. Hypoxia should be treated with O2

Question 7

Complications of pulmonary fibrosis

Answer 7

• GORD: patients with IPF, have an increased prevalence of GORD
• Pulmonary infection
• Pulmonary hypertension
• Lung cancer
• Respiratory failure

Question 8

Prognosis of pulmonary fibrosis

Answer 8

Would experience progressive dyspnoea and functional decline over time
Mean survival is 2-5 years after diagnosis
Advanced age, male sex, severe FVC impairment, large number of fibroblastic foci present etc are indicators of poor prognosis