Interstitial Lung Disease

Respiratory Station

Interstitial Lung Disease

Important Physical Signs

General :

Age (young – CF, TIS // old – COPD, ILD, Lung Malignancy more likely)
Cachectic (ILD, COPD, Lung Malignancy, CF, Bronchiectasis)
Tachypnoeic (count respiratory rate on air / oxygen)
Cushingoid (steroid use)
Asymmetric chest movement
Cough (productive vs dry)

Peripheral : (hands – arms – face – neck – torso)

Hands
- Peripheral cyanosis (blue finger pulp discolouration)
- Tar-stained fingers (check between index and middle fingers smokers)
- Rheumatoid hands (RA)
- Clubbing
  (suppurative lung disease, idiopathic pulmonary fibrosis)
- Sclerodactyly, calcinosis, pulp atrophy, terminal phalanx tufting , Raynaud’s (systemic sclerosis)
- Asterixis (CO2 retention)
- Small muscle wasting (Pancoast tumour)
- Radial pulse (bounding pulse CO2 retention) and respiratory rate (breathless)
Arms
- Muscle wasting (cachexia in lung malignancy, COPD)
- Bruising (steroid purpura)
- Rheumatoid nodules (elbows, ankles)
Face
- General
  - Plethoric (secondary polycythaemia)
  - Telangiectasia (systemic sclerosis)
  - Butterfly rash (SLE)
  - Lupus pernio (Sarcoidosis)
- Eyes
  - Conjunctival pallor
  - Horner’s syndrome (miosis, ptosis – Pancoast tumour)
  - Episcleritis (RA)
- Mouth
  - Central cyanosis under tongue (hypoxia)
  - Telangiectasia (systemic sclerosis)
  - Microstomia (systemic sclerosis)
- Neck
  - JVP (raised in cor pulmonale)
  - Tracheal deviation
  - Cricosternal distance (< 3 fingers in COPD)
  - Cervical lymphadenopathy
Torso
- Posterior thoracotomy scar (lung transplant, lobectomy)
- Chest drain scars (look close safety triangle)
- VATS scars
- Asymmetrical chest expansion (fibrosis)
Peripheral oedema (cor pulmonale)

Chest:

Bilateral bi-basal fine end-inspiratory crackles🔊 fixed non-altered by coughing
Reduced chest expansion

Presentation:

Diagnosis: Clinical findings are consistent with a diagnosis of interstitial lung disease affecting the upper/ lower zones as evidenced by:Most pertinent positive findings are –> Important Physical Signs

Audible bilateral end-inspiratory crackles in upper/lower zones fixed with coughing
Finger Clubbing
Rheumatoid hands and extensor nodules
Reduced chest expansion

I would like to suggest an underlying cause of ILD:

Rheumatoid Arthritis (peripheral symmetric deforming polyarthropathy)
Systemic Sclerosis (telangiectasia,Sclerodactyly, Microstomia)
SLE (butterfly rash, arthropathy)
Idiopathic pulmonary fibrosis (Clubbing)

Important negative findings include:

No evidence of acute respiratory failure with absence of peripheral or central cyanosis.
No signs of pulmonary hypertension (loud P2, RV heave, TR)
No evidence of cor pulmonale with no overt JVP rise, no RV heave and no peripheral oedema.
No evidence of CO2 retention with absence of CO2 flap.

To complete my examination I would like to measure oxygen saturations at rest, perform a peak flow test and obtain full drug and social/occupational history.

Differential Diagnosis:

There is a wide differential diagnosis here but what may be relevant to this particular patient is:

Pulmonary oedema secondary to left ventricular failure
Bronchiectasis (coarse crackles that change with coughing +/- wheeze)
Suppurative lung disease (consolidation, abscess)
Lung malignancy

Classification of interstitial lung disease

Exposure
- Drugs (Methotrexate, Amiodarone, Bleomycin, Nitrofurantoin, Phenytoin, Cyclophosphamide)
- Occupational (Asbestosis, Coal pneumoconiosis, Silicosis)
- Hypersensitivity Pneumonitis
Connective Tissue Disease
- Rheumatoid Arthritis
- Systemic Sclerosis
- SLE
- Polymyositis/Dermatomyositis
- Sjogren’s
- Vasculitis (eosinophilic granulomatosis)
- Sarcoidosis (upper zone)
- Ankylosing Spondylitis (upper zone)
Idiopathic
- Idiopathic pulmonary fibrosis
- Acute interstitial pneumonia (AIP)
- Non-specific interstitial pneumonia (NSIP)
Post-infection (asymmetrical fibrosis) [upper zone]
- TB
- ABPA
- Fungal

Clinical Judgement:

Bedside tests:

ABG – checking for type 2 respiratory failure
ECG – looking for right heart strain
Oxygen saturations
Serial peak flow measurements

Blood investigations:

FBC (polycythaemia in chronic hypoxia)
Inflammatory markers (CRP and ESR)
Autoimmune screen (ANA, anti-ds DNA, anti-Scl, RF, anti-CCP, ANCA)
Serum precipitins (hypersensitivity pneumonitis)
Serum ACE and adjusted calcium levels (Sarcoidosis)
Aspergillin RAST test, IgE specific to Aspergillus
Urea and electrolytes (drug-related ILD nephrotoxicity)
Liver function tests (liver derangement with antifibrotics)

Imaging Studies:

CXR – bilateral reticulonodular interstitial infiltrates
High Resolution CT Chest – ground-glass opacifications (NSIP), honeycombing (UIP)

Special tests:

Pulmonary Function Tests
- Spirometry (FVC, FEV1, FEV1/FVC ratio – restrictive defect)
- Lung volume plethysmography (reduced volumes FVC < 80% to assess suitability for
  antifibrotics, FEV < 1 unsuitable)
- 6-minute Walk Test (desaturation)
- Diffusion Capacity of Lungs for CO
  - Transfer factor and lung coefficient factor reduced
    - High DLCO : asthma, obesity, pulmonary haemorrhage, polycythaemia, leftright shunt
    - Low DLCO : Lung resection, ILD, emphysema, anaemia, pulmonary
      vascular disease
- Bronchoalveolar Lavage for cell types and cytology (lymphocytosis responsive to steroids in NSIP,
  eosinophilic pneumonia, asbestos bodies, malignant cells)
- Video-assisted transbronchial biopsy
- Echocardiogram to assess for pulmonary hypertension (RV hypertrophy, elevated RV systolic
  pressure)
- Right Heart Catheterisation (mean Pulmonary Artery Pressure > 25mmHg in PAH)

Management

MDT approach following referral to specialist tertiary centre
Treat underlying cause
Conservative
- Patient Education
- Lifestyle interventions – alcohol cessation, smoking cessation, encourage physical activity,
  balanced diet, vaccinations (pneumococcus, influenza, COVID-19)
- Remove causative allergen/agent
- Pulmonary rehabilitation
Medical
- Anti-fibrotic (pirfenidone) [FVC 50-80%, drop in FVC > 10% in 6/12]
- Tyrosine kinase inhibitors (nintedanib)
- Steroids and immunosuppression in CTD
- Long-term Oxygen Therapy
Surgical
- Single or double lung transplant
Manage complications
- Infective exacerbations
- Pulmonary hypertension (Group 3 – secondary to lung disease and hypoxia)
- Respiratory failure (Type 2 Respiratory Failure – restrictive defect)
- Lung cancer

Indications for lung transplant:

Single:

Emphysema
Idiopathic pulmonary fibrosis

Double:

Cystic fibrosis
Bronchiectasis
COPD (A1AT deficiency)
Pulmonary hypertension

Heart-Lung Transplant

Eisenmenger syndrome (transposition of great arteries, truncus arteriosus, atrioventricular canal)
Primary pulmonary hypertension (PAWP > 25mmHg)

Absolute contraindications:

Disseminated malignancy
Critical illness (major organ dysfunction)
Ventilator dependent
Current smoker
Poor social support network

Extra-articular manifestations of RA

Cardiovascular
- Pericarditis
- Vasculitis
- Pulmonary arterial hypertension
Pulmonary
- Interstitial lung disease
- Bronchiolitis obliterans
- Pleural effusions
- Caplan syndrome (pulmonary nodules and pneumoconiosis with dust inhalation)
- Pleuritis
Neurological
- Cervical myelopathy (C1-C2 subluxation seen on flexion-extension cervical radiography)
- Peripheral neuropathy
- Mononeuritis Multiplex (foot drop)
- Carpal tunnel
Metabolic
- Osteoporosis
- Steroid induced diabetes mellitus
Haematological
- Anaemia (chronic disease, methotrexate myelosuppression, NSAID gastropathy, Felty’s)
- Felty’s syndrome (RA, splenomegaly, neutropenia)
- Amyloidosis
Skin
- Rheumatoid nodules (firm or rubbery nodules on pressure areas i.e. olecranon)
Eyes
- Episcleritis/scleritis (acute red painful eye)
- Keratoconjunctivitis sicca (secondary Sjorgren syndrome)

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Interstitial Lung Disease

Respiratory Station