Restrictive lung disease

Question 1

What is restrictive lung disease?

Answer 1

• Characterised by ‘reduced lung volume’
• Intrinsic: parenchyma
• Extrinsic: Pleura; chest wall; neuromuscular diseases ‘respiratory pump’

Question 2

What are the characteristics of intrinsic restrictive lung disease?

Answer 2

• Characterised by ‘reduced lung volume’
• Increased elastic recoil of lung
• Hypoxia due to VQ mismatch

Question 3

List the different lung function tests

Answer 3

-Reduced total lung capacity
-Reduced forced vital capacity
-Preserved airflow( FEV)
-Increased FEV/FVC (ratio>70 is indicative of a restrictive lung disease)
-Gas transfer:
Reduced in lung parenchymal disease
Preserved in other causes of RLD

Question 4

What are the characteristics of extrinsic restrictive lung disease?

Answer 4

• Characterised by reduced lung volume
• Decreased compliance of respiratory system
• Hypoxia due to VQ mismatch from areas of atelectasis( collapse/closure of a lung resulting in reduced/absent gas exchange)

Question 5

Outline chest wall disease

Answer 5

• Kyphoscoliosis

- prevents lung expansion

Question 6

What disease may result from problems in the interstitum?

Answer 6

Infection: TB, PCP
Malignancy: lymphangitis
Vascular: Pulmonary oedema
ILD: autoimmune/CTD
ILD: idiopathic

Question 7

Define Interstitial lung disease

Answer 7

-Range of disorders characterised by cellular and extracellular matrix deposition within regions of lung distal to terminal bronchiole
Interstitium: area between alveolar epithelium& capillary endothelium

Question 8

Outline the causes of ILD

Answer 8

1. ) Systemic diseases: RA, SLE, CTD, scleroderma, vasculitis
2. ) Environmental: Abestosis, coal/silicosis
3. ) EAA(extrinsic allergic alveolitis)/ hypersensitivity pneumonitis: bird fancier’s lung; farmer’s lung
4. ) Drugs: Amiodarone; Nitrofurantoin; Bleomycin
5. ) Idiopathic interstitial pneumonia (ILP)

Question 9

Outline the characteristics of ILD

Answer 9

• Interstitum inflammation/fibrosis
• Impaired gas exchange
• Symptoms: SOB/cough
• Abnormal CXR
• Abnormal lung function: (restrictive, reduced lung volumes& gas transfer factor)

Question 10

How can we classify idiopathic interstitial pneumonia

Answer 10

• Usual interstitial pneumonia (UIP) aka interstial pulmonary fibrosis
• Non specific interstitial pneumonia (NSIP): rare disorder that affects the tissues that surrounds& separates tiny air sacs of the lungs
• Acute interstitial pneumonia (AIP): idiopathic ILD that is characterised by sudden onset of dyspnea and rapid development of respiratory failure
• Cryptogenic Organising pneumonia: swelling of the small airways in your lungs

Question 11

What can clubbing& crackles indicate?

Answer 11

• Idiopathic pulmonary fibrosis
• Bronchiectasis
• Cystic Fibrosis

Question 12

What is bronchiestasis?

Answer 12

A long-term condition where the airways of the lungs become abnormally widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection

Question 13

What diagnostic lung function tests exist

Answer 13

-FEV1
-FVC
-FEV1/FVC
TLCO

Question 14

Outline the characteristics of Usual interstitial pneumonia

Answer 14

• Aetiology unknown
• Proliferation of mesenchymal cells, collagen deposition, fibroblastic foci
• Minimal inflammation, fibrosis predominates
• Hypothesis: abnormal epithelial repair to unknown stimulus
• IFN, TNF, TGF, oxidants- important in pathogenesis

Question 15

What investigations are used when diagnosing restrictive lung disease?

Answer 15

-Bloods: FBC, AA(antinuclear antibodies),RhF
-CXR/HRCT
-Lung function test
-Oxygen saturation ( blood gases)
-Lung biopsy in some cases
Bronchoalveolar lavage: a diagnostic procedure by which cells and other components from bronchial and alveolar spaces are obtained for various studies.

Question 16

How can we treat idiopathic pulmonary fibrosis (IPF)

Answer 16

• Aims to reduce disease progression
• Pirfenidone: antifibrotic, oral, slows disease progression (FVC)& reduces mortality
• Nintedanib: Triple tyrosine kinase inhibitor (similar effect)
• oxygen
• pulmonary rehabilitation
• Palliative care
• Lung transplant

Question 17

Which systemic diseases can interstitial lung disease/ diffuse parenchymal lung disease present in?

Answer 17

• Ankylosing Spondylitis
• RA
• systemic sclerosis
• SLE
• Dermatomyositis

Question 18

What is sarcoidosis?

Answer 18

• Multi-system disease
• affects the lungs, skin and eyes(uveitis)
• Any organ
• Severe disease: heart, neuro
• Incidence highest in blacks, scandinavians& irish
• Familia<5%

Question 19

How can we treat ILD?

Answer 19

• Immunosuppression principles: QOL& threatened organ function
• steroids
• Methotrexate
• Hydroxchloroquine
• Anti-TNF
• Mycophenolate/Azathioprine
• some patients ONLY require observartion

Question 20

What may cause diffuse pleural thickening?

Answer 20

• Infection
• Asbestos
• Prevents lung expansion