Interstitial lung disease

Question 1

what are ILDs ?

Answer 1

this is any disease process affecting lung interstitium (i.e. alveoli, terminal bronchi)

Question 2

what are the key features of ILD?

Answer 2

interferes with gas transfer- this is why patients present with breathlessness

shows a restrictive lung pattern

Symptoms: breathlessness and dry cough

Question 3

it can be…

Answer 3

acute
episodic
chronic due to occupational or environmental agents or drugs
chronic with evidence of systemic disease
chronic with no evidence of systemic disease

Question 4

what is the pathophysiology ?

Answer 4

get impaired gas exchange - alveolar barrier to O2 exchange (i.e. alveolar-arteriolar barrier)

Question 5

what happens to the CO2 exchange?

Answer 5

CO2 exchange unimpaired as alveolar ventilation normal (CO2 is very soluble and blown off)

so get decreased PaO2 (decreased SaO2) normal PaCO2

Question 6

what are the clinical features of ILDs?

Answer 6

cough, usually dry, persistent and distressing

breathlessness

Question 7

what are the features of breathlessness?

Answer 7

usually slowly progressive, insidious onset, acute in some cases

Question 8

what are the common examination findings?

Answer 8

crackles
clubbing

central cyanosis and signs of right heart failure in advanced disease

Question 9

what are the features of the crackles?

Answer 9

typically bilateral and basal

Question 10

where is clubbing common?

Answer 10

in idiopathic pulmonary fibrosis but it is also seen in other types e.g. asbestosis

Question 11

what is normally see on a CXR?

Answer 11

typically small lung volumes with reticulonodular shadowing but may be normal in early or limited disease

Question 12

what is normally seen on a HRCT?

Answer 12

combinations of ground glass changes, reticulonodular shadowing, honeycomb cysts and traction bronchiectases, depending on the stage of disease

Question 13

what are the features of pulmonary function?

Answer 13

typically restrictive ventilatory defect with reduced lung volumes and impaired gas exchange

exercise tests assess exercise tolerance and exercise related fall is Sa O2

Question 14

what are the categories of ILD?

Answer 14

ILD of known cause e.g. drugs or association

idiopathic interstitial pneumonia -Main ones

• idiopathic pulmonary fibrosis (IPF)
• IIP other than IPF
  
  1. respiratory bronchiolitis interstitial lung disease
  2. desquamative interstitial pneumonia
  3. acute interstitial pneumonia
  4. cryptogenic organising pneumonia
  5. lymphocytic interstitial pneumonia
  6. nonspecific interstitial pneumonia

Granulomatous ILD e.g. sarcoidosis, EAA

other forms of ILD e.g. LAM

Question 15

what are the causes of ILD?

Answer 15

Fluid in the alveolar spaces

Consolidation of Alveolar Air Spaces

Inflammatory Infiltrate of Alveolar Walls (i.e. Alveolitis): Granulomatous Alveolitis

Dust Disease (Pneumoconiosis)

Carcinomatosis

Eosinophilic (Type ⅓ Allergic response

Question 16

what can cause fluid in the alveolar space?

Answer 16

cardiac Po oedema due to raised venous pressure i.e. let heart failure

and non cardiac Po oedema- this means that there is normal po venous pressure but leaky Po capillaries

Question 17

what may cause Cardia Po oedema

Answer 17

congestive heart failure that leads to PO may be cause by:

heart attack or any disease of the heart that weakens or stiffens the heart muscle

leaking or narrowed heart valves (mitral or aortic valves)

sudden, severe hypertension

Question 18

what are the causes of non-cardiac PO?

Answer 18

sepsis or trauma (ARDS aka shock lung)

may also be altitude sickness

Question 19

what causes consolidation of alveolar air spaces?

Answer 19

infective pneumonia

infarction

bronchiolitis obliterans organising pneumonia

rheumatoid disease

drugs

cryptogenic

Question 20

what are the viral organisms of infective pneumonia causing consolidation of alveolar air spaces in ILD?

Answer 20

influenza, measles, chickenpox

Question 21

what are the bacterial organisms of infective pneumonia causing consolidation of alveolar air spaces in ILD?

Answer 21

pneumococcus, TB

Question 22

what are the fungal organisms of infective pneumonia causing consolidation of alveolar air spaces in ILD?

Answer 22

HIV/ pneumocystic

Question 23

what are the parasites organisms of infective pneumonia causing consolidation of alveolar air spaces in ILD?

Answer 23

toxocara, filaria

Question 24

what may cause infarction?

Answer 24

PE

vasculitis

Question 25

what is bronchiolitis obliterans organising pneumonia?

Answer 25

a non-infectious pneumonia, just an inflammation of the bronchioles and surrounding tissue in the lungs

Question 26

what are the causes of ILD by granulomatous alveolitis?

Answer 26

EAA

sarcoidosis

Drug induced alveolitis

Toxic gas/fumes: chlorine

fibrosing alveolitis

autoimmune

Question 27

what is EAA?

Answer 27

hypersensitivity pneumonitis type 3 reactions

farmers lung

avian (pigeon budgie)

Question 28

what is sarcoidosis?

Answer 28

multi system disease

causes lymphadenopathy/ erythema nodosum/ uveitis/ myocarditis/ neuropathy

Question 29

what drugs cause alveolitis?

Answer 29

amiodarone
Bleomycin, Methotrexate
Gold

Question 30

what is firbosing alveolitis?

Answer 30

rheumatoid, Cryptogenic (IPF)

Question 31

what are the autoimmune causes of granulomatous alveolitis ?

Answer 31

SLE, Polyarteritis, Wegener’s, Churg-Strauss, Bechet’s

Question 32

what are the dust diseases that cause ILDs?

Answer 32

Fibrogenic

• asbestosis
• silicosis

Non-fibrogenic

• siderosis (Iron)
• Stannosis (Tin)
• Baritosis (Barium)

Question 33

what are the carcinomatosis causes of ILD?

Answer 33

Lymphatic/Blood Spread

adenocarcinoma- bronchus, breast, prostate, colon, stomach

Question 34

what causes the eosinophilic (type1/ 3 allergic response)

Answer 34

Drugs - Nitrofurantoin
Fungal - Aspergillosis
Parasites - Toxocara, Ascaris, Filaria
Autoimmune -Churg Strauss,Polyarteritis