Idiopathic Pulmonary Fibrosis Flashcards
Define Idiopathic Pulmonary Fibrosis?
Inflammatory condition of the lung resulting in fibrosis of the alveoli and interstitium
Previously known as Cryptogenic fibrosing alveolitis
What is the aetiology of Idiopathic Pulmonary Fibrosis?
Occurs in generally predisposed individuals
Recurrent injury to alveolar epithelial cells results in secretion of cytokines and growth factors
This leads to fibroblast activation, recruitment, proliferation, differentiations into myofibroblasts and increased collagen synthesis and deposition
Certain drugs can produce similar illness (e.g. methotrexate, amiodarone)
What is the histological pattern of Idiopathic Pulmonary Fibrosis?
Interstitial pneumonia
What are the risk factors for Idiopathic Pulmonary Fibrosis?
Smoking
Occupational exposure to metal or wood
Chronic microaspiration
Animal and vegetable dusts
What is the epidemiology of Idiopathic Pulmonary Fibrosis?
RARE
6/100,000
More common in MALES
What are the presenting symptoms of Idiopathic Pulmonary Fibrosis?
Gradual-onset, progressive dyspnoea on exertion
Dry irritating cough
No wheeze
Symptoms may be preceded by a viral-type illness
Fatigue and weight loss are common
What do we make sure to ask on the history for Idiopathic Pulmonary Fibrosis?
Take a full occupational and drug history
What are the signs of Idiopathic Pulmonary Fibrosis?
Clubbing (50%)
Bibasal fine late inspiratory crackles
Signs of right heart failure in advanced stages of disease
What bloods do we do for Idiopathic Pulmonary Fibrosis?
ABG
ANA and Rheumatoid Factor
What do we see specifically on a ABG for Idiopathic Pulmonary Fibrosis?
Normal in early disease
PO2 decreases with exercise
Normal PCO2 which rises in late stage disease
Why do we test ANA and Rheumatoid Factor for Idiopathic Pulmonary Fibrosis?
1/3 of patients are positive for ANA or RF
What do we see on a CXR for Idiopathic Pulmonary Fibrosis?
Usually normal at presentation
Early disease may show ground glass shadowing
Later stage disease shows reticulonodular shadowing, signs of cor pulnonale and, evnetually honeycombing
Why might we do a High-Resolution CT for Idiopathic Pulmonary Fibrosis?
More sensitive in early disease than CXR
What do we see om Pulmonary Function Tests for Idiopathic Pulmonary Fibrosis ?
Restrictive features (reduced FEV1 and FVC, with preserved or increased FEV1/FVC)
Decreased lung volumes
Decreased lung compliance
Decreased total lung capacity
Why do we do Bronchoalveolar Lavage for Idiopathic Pulmonary Fibrosis?
Exclude infections and malignancy
