Interstitial Lung Disease

Question 1

Interstitial Lung Disease is ….?

Answer 1

Insulted lung that has become fibrosed resulting in decreased diffusion = hypoxic not hypercapnic

characterised by chronic inflammation and/or progressive interstitial fibrosis with hyperplasia or type II pneumocytes, that affects the lung parenchyma

Question 2

Known causes?

Answer 2

Occupational: Asbestos, Silicosis, Bird Poo, Coal

Drugs: Methotrexate, amiodarone
Hypersensitivities: extrinsic allergic alveolitis ->granuloma
Infections: TB -> Granuloma , Fungal

Associated system disorders: 
Sarcoidosis
RA
Connective tissue diesease (eg SLE) 
UC, RTA, AI thyroid disease

Idiopathic:
Idiopathic pulmonary fibrosis - MOST COMMON ILD
cryptogenic organising pneumonia
lymphocytic interstitial pneumonia

Question 3

Hx + PC

Answer 3

Present with a dry cough, dyspnea, lethargy, malaise

systemic symptoms: weight loss, fatigue, fever, rash and arthralgia

Question 4

Important past Hx and Meds/treatment

Answer 4

PMHx

• Radiotherapy
• Infections (asp pneumonia, TB)

Meds

• Cardiac drugs - amiodarone, hydralazine, procainamide
• Rheum - methotrexate
• Chemo - bleomycin
• Other - Nitrofurantoin

Social hx -exposure
Mineral dust - silicosis, asbestos
Chemical - nitrogen dioxide, chlorine, ammonia
Organic dust - avian proteins, fungal spores

Question 5

Examination for ILD

Answer 5

General
Peripheries - clubbing + cyanosis

Chest
- Velcro fine crackles (dec O2, inc RR)

Signs of pulmonary HTN

• elevated JVP (with large V wave)
• Parasternal impulse (RV heave)
• Tricuspid regurg

Other
- signs of systemic disease

Question 6

Investigations

Answer 6

CXR
- can be normal, dec lung volume, diffuse opacity

High Res CT

• localised
• diffuse ILD - honey comb lung in IPF
• pleural thickening (eg asbestosis)

Spiro
- restrictive patterns

Bloods

• FBC - high ESR/CRP, eosinophilia
• Hypergammaglobulinaemia
• Raised LDH
• Rheum serology - ANA, Rh
• ABG - low PaO2, normal or high PaCO2, wide Aa Gradient

Bronchoalveolar lavage (BAL)

• inc lymphocytes = more likely top respond to treatment
• inc polymorphonuclear cells = less likely

Biopsy

• transbronchial = rule out infection, sarcoidosis, carcinoma
• thorascopic - for diagnosis of Idiopathic ILD

Question 7

Management of ILD - NP

Answer 7

Smoking cessation 
remove exposure 
pneumococcal and influenza vaccine 
home O2 for symptomatic relief or hypoxic patients 
pulmonary rehab

Question 8

Management - P

Answer 8

treatment will not reverse if established fibrosis
if active inflammation, treatment may help = STEROID- consider maintenance steroids if improve/stabilise

Immunosuppressive agents for sarcoidosis, mesothelioma or secondary to RA

Lung transplant