Idiopathic pulmonary fibrosis Flashcards
Define idiopathic pulmonary fibrosis
Idiopathic pulmonary fibrosis = idiopathic fibrosing alveolitis = inflammatory condition of the lung resulting in fibrosis of alveoli and interstitium
Characterised by scar tissue within the lungs and progressive SOB
Explain the aetiology / risk factors of idiopathic pulmonary fibrosis
Unknown aetiology
o Possible theory = unidentified insult causes damage to alveolar epithelium/endothelium/BM
Cigarette smoke, organic or metal dust, GORD; DM, infection
Risk factors
• Smoking
• Occupational exposure - Metal, wood, animal or vegetable dusts
• Drugs - Amiodarone, methotrexate, bleomycin, sulfasalazine
Summarise the epidemiology of idiopathic pulmonary fibrosis
- Rare - Prevalence in UK of about 6 in 100,000
- Mean age of diagnosis is 60-70 y/o
- More common in men
Recognise the presenting symptoms of idiopathic pulmonary fibrosis
- Gradual onset - SOBOE
- Dry cough - NO wheeze
- Possible preceding viral-type illness
- Fatigue, weight loss, malaise
Recognise the signs of idiopathic pulmonary fibrosis on physical examination
Clubbing (50%)
Bibasal fine inspiratory crackles
Signs of RHS HF in late stages
o RV heave
o Raised JVP
o Peripheral oedema
Identify appropriate investigations for idiopathic pulmonary fibrosis
CXR – 1st line
o Usually normal at presentation
o Early - Small lung fields
o Late - Reticulonodular shadowing at the bases, Ground glass appearance, Honeycomb appearance, Signs of cor pulmonale
CT
o Reticular densities, honeycombing and traction bronchiectasis - Lower zone and subpleural areas
ABG
o Hypoxia with exercise
o Raised PCO2 in late disease
Serology
o 1/3 are RF or ANA positive
Spirometry
o Restrictive ventilator defect = reduced FEV1, reduced FVC, normal FEV1/FVC
o Reduced lung volumes
o Reduced lung compliance
Bronchoalveolar lavage
o Exclude infections and malignancy
Lung biopsy - GS
o Gold standard but may not be appropriate
