Pulmonary fibrosis

Question 1

What is PF?

Answer 1

· A rare, chronic, idiopathic life-threatening disease that manifests over several years.
· Characterised by scar tissue within the lungs and progressive dyspnoea.
· Most common form of the group of interstitial lung diseases (restrictive).

Question 2

What is the epidemiology of PF?

Answer 2

· Prevalence increases with advancing age.
· Mean age of diagnosis of between 60-70 years.
· More common among men.

Question 3

What is the pathophysiology of PF?

Answer 3

· Pro-inflammatory and pro-fibrotic response with an influx of macrophages, fibroblasts and other inflammatory cells.
· Dysregulation of the normal tissue repair process.
· Formation of fibroblastic foci - pathological hallmark of the disease.
· Alveolar destruction, infiltration of interstitial space with fibrosis and distortion of the lung parenchyma.

Question 4

What is the prognosis of PF?

Answer 4

· Median survival of 2-5 years from the time of diagnosis.

· Progressive dyspnoea and functional decline.

Question 5

What is the aetiology of PF?

Answer 5

Unknown but with possible theories:
· Unidentified insult causes damage to the alveolar epithelium, endothelium and basement membrane.
· Cigarette smoke, organic or metal dust, GORD, diabetes and viral infection.

Question 6

List the common risk factors related to PF.

Answer 6

· Advanced age.
· Male.
· FHx - familial pulmonary fibrosis.
· Cigarette smoking.

Question 7

List the weak factors related to PF.

Answer 7

GORD, infection, diabetes.

Question 8

List the common signs and symptoms related to PF.

Answer 8

· Dyspnoea - with exertion.
· Cough - typically non-productive. 
· Crackles - end-expiratory, basilar crackles. 
· Weight loss, fatigue and malaise. 
· Clubbing.

Question 9

What investigations would you request if you suspected a patient had PF?

Answer 9

· CXR - basilar, peripheral, bilaterally, asymmetrical, reticular opacities – most prominent in lower lung zones.

· High-resolution CT chest - honeycombing.

· Pulmonary function tests - restrictive changes.

· ANA’s (anti-nuclear antibodies), RF (rheumatoid factor).

Question 10

Differentials?

Answer 10

· Pneumonia’s.
· Different types of interstitial lung disease.
· Asbestosis.
· Sarcoidosis.

Question 11

What is the treatment option for an acute exacerbation of PF?

Answer 11

· Admission to hospital + high-dose corticosteroid (prednisolone - 30mg daily).
· Cytotoxic therapy.

Question 12

What is the treatment option for a patient not experiencing acute exacerbation of PF?

Answer 12

· Anti-fibrotic therapy - pirfenidone, nintedanib.
· Smoking cessation + pulmonary rehabilitation +/- oxygen.
· PPI.
· Lung transplant.

Question 13

Complications?

Answer 13

· GORD. 
· Pulmonary infection. 
· Pulmonary hypertension. 
· Lung cancer. 
· Pneumothorax. 
· DVT/PE. 
· Acute coronary syndrome.