Interstitial lung disease Flashcards Preview

Respiriatory: Airway Disease > Interstitial lung disease > Flashcards

Flashcards in Interstitial lung disease Deck (37)
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1

What comprise the pulmonary interstitium?

* Alveolar lining cells type 1 and 2
* Thin elastin-rich connective component containing capillary blood vessels

2

What takes place across alveolar walls?

Gas exchange

3

What are the features of alveolar walls?

* Elastic structure (allowing for ventilation)
* Very thin (allowing gas exchange)

4

What is the early stage of interstitial lung disease?

Alveolitis - injury with inflammatory cell infiltration

5

What is associated with acute ILD?

Adult respiratory distress syndrome (ARDS)

6

What is the late stage of ILD?

Fibrosis

7

What do the clinical effects of ILD occur due to?

* Hypoxia (respiratory failure)
* Cardiac failure

8

Is fibrosis in ILD diffuse or localised?

Diffuse fibrosis – localised scarring won’t cause many problems

9

What are causes of ILD?

* Environmental (minerals, drugs, radiation
* Post-ARDS (post-infective episode)
* Hypersensitivity (mouldy hay, avian proteins)
* Unknown (idiopathic)
* Connective tissue diseases – SLE, rheumatoid
* Idiopathic pulmonary fibrosis (IPF)

10

How is ILD diagnosed?

Based on clinical features often with biopsy

11

What are biopsy methods in ILD?

Transbronchial biopsy – special forceps used in bronchoscopy (good for picking up granulomas in the case of TB, sarcoid etc)
Thoracoscopic biopsy – more invasive but more reliable and generates far more tissue

12

What is lymphocytic interstitial pneumonia?

A cause of ILD

13

What is lymphocytic interstitial pneumonia associated with?

HIV

14

What are causes of chronic ILD?

* Idiopathic pulmonary fibrosis (IPF)
* Sarcoidosis
* Extrinsic allergic alveolitis (hypersensitivity pneumonitis)
* Pneumoconiosis
* Connective tissue diseases

15

What is idiopathic pulmonary fibrosis (IPF) also known as?

Cryptogenic fibrosing alveolitis (CFA) or Usual interstitial pneumonia (UIP)

16

What is IPF?

Progressive interstitial fibrosis of unknown cause

17

What are the clinical features of IPF?

* Variable associated inflammation
* Finger clubbing

18

What is the pathology of IPF?

* Subpleural and basal fibrosis
* Inflammatory component variable
* Terminally lung structure replaced by dilated spaces surrounded by fibrous walls (honeycomb lung)

19

What is extrinsic allergic alveolitis also known as?

Hypersensitivity pneumonitis

20

What is EAA?

A chronic inflammatory disease affecting the small airways and interstitium with an allergic origin (type III and IV hypersensitivity mixed allergic response)

21

What is EAA characterised by?

Occasional granulomas

22

What allergic responses are involved in EAA?

Mixed allergic response
* Type III - antibody mediated
* Type IV - T cell mediated, granuloma formation

23

What are causes of EAA?

* Thermophilic bacteria – Farmers lung
* Avian proteins – Bird fanciers lung
* Fungi – Malt workers lung

24

What is used to diagnose EAA?

* Precipitins (antibodies) often detectable in serum
* Biopsy

25

What is sarcoidosis?

Multisystem granulomatous disorder of unknown cause

26

What are clinical features of sarcoidosis?

* Granuloma formation
* Uveitis (inflammation of iris)
* Erythema nodosum
* Lymphadenopathy
* Hypercalcaemia

27

How is sarcoidosis diagnosed?

* CXR - often see bilateral hilar lymphadenopathy
* Restrictive defect in PFT
* Transbronchial biopsy - granuloma

28

TB and sarcoidosis both result in granuloma formation. How are the 2 distinguishable from one another?

TB involves necrosis, sarcoidosis does not

29

What is a common side effect of chronic sarcoidosis?

Fibrosis due to chronic inflammation

30

In what ways can connective tissue diseases affect the respiratory system?

* Interstitial fibrosis (milder than IPF)
* Pleural effusions
* Rheumatoid nodules