Interstitial Lung Disease (Pulmonary Fibrosis) Flashcards
What is the definition of ILD / pulmonary fibrosis / diffuse parenchymal lung disease?
Diffuse fibrosis of alveoli and perialveoli tissues
Leading to impairment of gas excahnge
Restrictive lung pathology
Diffuse infiltrates on radiography
What are the clinical signs of pulmonary fibrosis?
General
1. Comment on functional status: breathless/comfortable, oxygen therapy
2. Ask patient to cough - non-productive cough (ILD), productive cough (not ILD, unless infection)
3. Signs of associated autoimmune disease - determines etiolgoy of ILD
4. Signs of ILD treatment - steroid purpura, ciclosporin gingival hyperplasia
4A. Slate grey skin discolouration secondary to amiodarone
Peripheral
5. Clubbing
6. Peripheral and central cyanosis
7. Usually no palpable lymph nodes (unless sarcoidosis, malignancy)
Chest
8. Chest expansion equal but reduced bilaterally
9. Dull percussion, reduced focal fremitus over affected region (upper or lower)
10. Fine end inspiratory crepitations that do not change on coughing
11. Signs of pulmonary hypertension
(wheeze - indicates obstructive airways, or sarcoidosis, NOT cryptogenic ILD)
What are the causes of an upper zone/apical fibrosis?
(M: HCP BREAASTS)
- Histiocytosis X
- Coal workers pneumoconiosis
- Psoriasis
- Berylliosis
- Radiation
- Extrinsic allergic alveolitis
- Ankylosing spondylitis
- Aspergillus ABPA
- Silicosis
- Tuberculosis
- Sarcoidosis
What are the causes of lower zone/basal fibrosis?
(M: RAIDS)
- Most Rheumatology/CTD except AS, psoriasis
- Rheumatoid arthritis
- Asbestosis
- Idiopathic/cryptogenic pulmonary fibrosis
- Drugs (M: Go BAN Me)
- MTX, azathioprine, bleomycin, busulphan, cyclo, chlorambucil
- Amitryptyline, phenytoin, carbamazepine
- Amiodarone, hydralazine, procainamide
- Nitrofurantoin, isoniazid
- Gold, sulphasalazine - Scleroderma, systemic sclerosis, SLE, Sjogren’s syndrome
(Asbestos is massive crystal thus affect lower zone)
What are the causes of generalised fibrosis?
(M: PLANT)
- Pulmonary haemorrhage and vasculitis syndromes - PAN, WG, CS, Goodpasture
- Lymphangiomyomatosis, carcinomatous lymphangitis
- Alveolar proteinosis (silica, aluminum dust, chronic infection, malignancy)
- Neurofibromatosis
- Tuberous sclerosis
How would you investigate a patient with suspected pulmonary fibrosis?
- Bloods
- FBC: anaemia (vasculitis), polycythaemia (chronic hypoxia), leukocytosis (hypersensitivity), eosinophilia
- Inflammatory markers (ESR, CRP)
- ABG: type 1 respiratory failure
- Immunoglobulin
- Autoimmune (ANA, RF, ENA, ANCA, anti-GBM, SLE)
- CK in polymyositis and dermatomyositis
- Precipitins - hypersensitivity pneumonitis
- Serum ACE - sarcoidosis - CXR
- Bilateral reticulonodular changes (upper/lower)
- Honeycombing appearance (advanced disease)
- Loss of heart border definition
- Small lungs
- Bilateral hilar lymphadenopathy (sarcoidosis)
- Calcified pleural plaques (asbestosis) - Lung function test
- Restrictive pattern: FEV1/FVC > 0.7
- Low TLC, FRC
- Reduced transfer factors/coefficient - HRCT or MRI Thorax
- Early: ground glass, interstitial thickening in subpleural distribution
- Late: honeycombing, areas of fibrosis, traction bronchiectasis - Bronchoalveolar lavage
- Lymphocytosis - indicates steroid responsiveness, better prognosis
- Look for malignant cells, asbestos bodies, eosinophils
- To exclude infection prior to starting treatment - Lung biopsy - identify etiology of ILD
What are the complications of ILD?
- Respiratory failure
- Recurrent chest infection
- Pulmonary hypertension and cor pulmonale
- Lung carcinoma
How would you manage patients with ILD?
General
1. Multidisciplinary teams - respi, PT, OT, RT
2. Cessation of triggers - stop smoking, remove exposure/change workplace
3. Treat infections (antibiotics) and symptoms (NAC)
4. LTOT if indicated
Immunosuppression
5. Prednisolone 40mg OM for at least 6 weeks, continue if good response
- Taper and discontinue over 1 week if response is not good
6. Steroid non-responsive - consider azathioprine, methotrexate, cyclophosphamide
7. Pirfenidone for usual interstitial pneumonia when FEV1 50-80% predicted
8. Others - colchicine, D-penicillamine for idiopathic ILD
Surgery
9. Single or double lung transplantat - advanced disease
(survival: single 74% at 1 year, 58% at 3 years, 47% at 5 years, 25% at 10 years)
What is the prognosis of pulmonary fibrosis?
Variable as depends on aetiology
Increased risk of bronchogenic carcinoma
Highly cellular with ground glass infiltrates
–> Responds to immunosuppression –> 80% 5 year survival
Honeycombing
–> Usually no response to immunosuppression –> 80% 5 year mortality
Affected zone of fibrosis and peripheral stigmata differentiating different CTD resultant ILD
A. Upper zone fibrosis
1. Ankylosing spondylitis
- Loss of lumbar lordosis
- Fixed kyphosis
- Stooped posture
2. Sarcoidosis
- Erythema nodosum
- Maculopapular skin lesions
- Lupus pernio
- Lymphadenopathy
3. Radiation therapy
- Erythema or field markings on chest wall
B. Lower lobe fibrosis
4. Rheumatoid arthritis
- Symmetrical deformed arthropathy over the hands
- Rheumatoid nodules
5. Systemic sclerosis
- Tight, shiny skin
- Telangiectasis
- Sclerodactyly
- Calcinosis
- Atrophic nails
- Raynaud’s phenomenon
6. SLE
- Petechial rash, purpura
- Livedo reticularis
- Arthropathy
- Butterfly malar rash
7. Dermatomyositis
- Gottron’s papules
- Heliotrope rash over eyelid/periorbital
- Proximal myopathy
8. Amiodarone use
- Grey slate skin pigmentation
- Irregular pulse
C. Generalised
9. Neurofibromatosis
- Neurofiromas and cafe-au-lait patches
What is the ATS/ERS classification of idiopathic pulmonary fibrosis?
- Acute (AIP)
- Usual (UIP)
- Non-specific (NSIP)
- Desquamative (DIP)
- Lymphoid (LIP)
- Cryptogenic organising pneumonia (COP)
- Respiratory bronchiolitis-ILD (RB-ILD)
What is Hamman-Rich syndrome?
Rapid progressive and fatal variant of interstitial lung disease
