4. Interstitial Lung Disease

Question 1

What are interstitial lung diseases?

Answer 1

Cause fibrosis of pulmonary interstitium

Question 2

Is pulmonary fibrosis obstructive or resitrictive?

Answer 2

Restrictive

Question 3

What are the 3 subdivisions of the interstitial space?

Answer 3

Bronchovascular
Parenchymal
Subpleural

Question 4

Where is the bronchovascular space?

Answer 4

Surrounds bronchi, arteries and veins

Question 5

Where is the parenchymal space?

Answer 5

Between alveoli and capillary BM

Question 6

Where is the subpleural space?

Answer 6

Between pleura and interlobular space

Question 7

What interstitial lung disease is considered occupational?

Answer 7

Pneumoconiosis: inhalation of dusts

Question 8

What is simple coal worker’s pneumoconiosis?

Answer 8

Dust accumulates around bronchioles
Coal macules and nodules are found in lungs
Affects upper lobes
Can cause emphysema

Question 9

What are coal macules in SCWP caused by?

Answer 9

Dust laden macrophages

Question 10

What are coal nodules in SCWP caused by?

Answer 10

Collagen fibres

Question 11

What is complicated CWP?

Answer 11

Progressive massive fibrosis
Progression of SCWP after 10-20 years
Black scars on lungs
Lead to cor pulmonale

Question 12

What is Caplan syndrome?

Answer 12

RA and pneumoconiosis

Nodular pulmonary lesions

Question 13

What does silicosis increase the risk of?

Answer 13

TB
Caplan syndrome
Lung carcinoma

Question 14

What are the 2 types of asbestos fibres?

Answer 14

Serpentine and amphibolic

Question 15

What does asbestos increase the risk of?

Answer 15

Pleural plaques
Pleural effusions
Asbestosis
Mesothelioma
Bronchogenic carcinoma

Question 16

What is asbestosis?

Answer 16

Asbestos fibres surrounded by macrophages and coated with iron: dumbbell shaped fibres called ferruginous bodies
Cause interstitial fibrosis and honeycombing of the lungs
Starts in lower lobes and moves up

Question 17

What is hypersensitivity pneumonitis?

Answer 17

Type 3 hypersensitivity to organic inhaled antigens
Progression to type 4 leads to pulmonary fibrosis
Onset is 6-8 hours after exposure

Question 18

What is included under idiopathic pulmonary fibrosis?

Answer 18

Sarcoidosis

Langerhans cell histiocytosis

Question 19

What effects does sarcoidosis have on the lungs?

Answer 19

Bihilar lymphadenopathy

Interstitial inflammation progessing to diffuse interstitial fibrosis

Question 20

What are the blood results in sarcoidosis?

Answer 20

High calcium, Alk Phos and ACE

Question 21

What method is used to sample lymph nodes from the hilum of the lung?

Answer 21

EBUS-TBNA

Question 22

What is the pathogeneis of idiopathic pulmonary fibrosis?

Answer 22

Alveolar wall injury causes interstitial oedema, accumulation of inflammatory cells
Heals by fibrosis

Question 23

What is the hallmark of idiopathic pulmonary fibrosis?

Answer 23

Heterogenous appearance: areas of fibrosis and inflammation alternating with normal lung

Question 24

What can be heard in idiopathic pulmonary fibrosis when auscultating?

Answer 24

Velcro crackles

Question 25

What is ARDS?

Answer 25

Acute Respiratory Distress Syndrome
Reduced gas exchange caused by diffuse injury to alveolar-capillary barrier
Alveolus filled with proteinaceous fluid and inflammatory cells

Question 26

What are the direct causes of ARDS?

Answer 26

Pneumonia

Aspiration of gastric contents

Question 27

What are the indirect causes of ARDS?

Answer 27

Sepsis

Severe trauma