Pulmonary fibrosis

Question 1

Clinical signs of pulmonary fibrosis

Answer 1

• Clubbing, central cyanosis and tachypnoea
• Fine end‐inspiratory crackles (like Velcro® which do not change with coughing)
• Signs of associated autoimmune diseases, e.g. RA (hands), SLE and systemic sclerosis (face and hands)
• Signs of treatment, e.g. Cushingoid from steroids
• Discoloured skin (grey) – amiodarone
• Unless there are any associated features then describe your findings as pulmonary fibrosis, which is a clinical description pending further differentiation following investigations

Question 2

Investigation for pulmonary fibrosis

Answer 2

• Bloods: ESR, rheumatoid factor and ANA
• CXR: reticulonodular changes; loss of definition of either heart border; small lungs
• ABG: type I respiratory failure
• Lung function tests:
  ⚬⚬ FEV1/FVC > 0.8 (restrictive)
  ⚬⚬ Low TLC (small lungs)
  ⚬⚬ Reduced TLco and KCO
• Bronchoalveolar lavage: main indication is to exclude any infection prior to immunosuppressants plus if lymphocytes > neutrophils indicate a better response to steroids and a better prognosis (sarcoidosis)
• High-resolution CT scan: distribution helps with diagnosis; bibasal subpleural honeycombing typical of UIP; widespread ground glass shadowing more likely to be non‐specific interstitial pneumonia often associated with autoimmune disease; if apical in distribution then think of sarcoidosis, ABPA, old TB, hypersensitivity pneumonitis, Langerhan’s cell histiocytosis.
• Lung biopsy (associated morbidity ~7%)

Question 3

Treatment of pulmonary fibrosis

Answer 3

• Pulmonary rehabilitation
• Immunosuppression if likely to be inflammatory; i.e. non‐specific interstitial pneumonia e.g. steroids: combination of steroids and azathioprine no longer used following results of PANTHER trial which showed increased morbidity on this combination
• Pirfenidone, Nintedanib (an antifibrotic agent) ‐ for UIP when FEV1 50–80% predicted (NICE recommended)
• N‐acetyl cycsteine – free radical scavenger
• Single lung transplant
• NB: Beware single lung transplantation patient – unilateral fine crackles and contralateral thoracotomy scar with normal breath sounds

Question 4

Prognosis of pulmonary fibrosis

Answer 4

• Very variable: depends on aetiology
• Highly cellular with ground glass infiltrate – responds to immunosuppression: 80% 5‐year survival
• Honeycombing on CT – no response to immunosuppression: 80% 5‐year mortality
• There is an increased risk of bronchogenic carcinoma

Question 5

Causes of basal fibrosis

Answer 5

• Usual interstitial pneumonia (UIP)
• Asbestosis
• Connective tissue diseases
• Aspiration

Question 6

Causes of fibrotic shadowing on CXR

Answer 6

Upper Zone (TRASHE)
- TB
- Radiotherapy
- Ankylosing spondylitis
- Sarcoidosis
- Histoplasmosis, Histiocytosis X
- Extrinsic allergic alveolitis
Mid Zone
- Progressive massive Fibrosis
Lower zone
- Usual interstitial pneumonia (UIP)
- Asbestosis
- Connective tissue disease
- Aspiration