Idiopathic Pulmonary Fibrosis

Question 1

Define Idiopathic Pulmonary Fibrosis

Answer 1

Chronic progressive scarring of the lungs leading to a decline in lung function and progressive dyspnoea

AKA idiopathic fibrosing alveolitis, cryptogenic fibrosing alveolitis

Question 2

Aetiology of Idiopathic Pulmonary Fibrosis

Answer 2

Unknown
Suggested: insult causes damages to the alveolar epithelium, endothelium and BM -> fibroblast activation -> differentiation into myofibroblasts -> colllagen synthesis -> fibrosis/scar tissue build up -> reduced elasticity

May be a familial form: familial pulmonary fibrosis (FPF), which affects at a younger age - autosomal dominant inheritance with incomplete penetration

Question 3

Risk factors for Idiopathic Pulmonary Fibrosis

Answer 3

Age >60 
Smoking
Family History 
Males
Organic/metal dust | GORD | DM | viral exposure

Question 4

Symptoms of Idiopathic Pulmonary Fibrosis

Answer 4

Dyspnoea (on exertion, progressive, present for >6 months)
Cough (non-productive, may be severe and unresponsive to medication)
Weight loss, fatigue, malaise, loss of appetite

Question 5

Signs of Idiopathic Pulmonary Fibrosis

Answer 5

End-expiratory basilar fine crackles
Clubbing

Advanced: RHF signs (Raised JVP, peripheral oedema, ascites, hepatosplenomegaly)

Question 6

Investigations for Idiopathic Pulmonary Fibrosis

Answer 6

Bronchoscope + biopsy: Fibrosis

Lung function: Restrictive (reduced FEV1, FVC, normal FEV1/FVC ratio)
Bronchoalevolar lavage: normal, rule out infection + malignancy

ABG: Normal in early disease, reduced pCO2 with exercise, pCO2 raised in late disease

CXR: small lung fields with ground glass shadowing -> reticulonodular shadowing esp. in bases -> honey combing
CT: Fibrotic changes in both lungs, esp. at bases and periphery, reticulation, Ground glass shadowing and honey combing