Restrictive (Interstitial) Lung Diseases

Question 1

What is interstitium?

Answer 1

The connective tissue space

around the airways and vessels

and the space between the basement membranes of the alveolar walls

Question 2

Describe the relationship between the normal alveolar wall and most of the alveolar epithelial (pneumocyte) & interstitial capillary endothelial cell basement membranes

Answer 2

They are in direct contact

Question 3

What is the material which impedes the elasticity of the alveoli (reducing compliance)?

Answer 3

Collagen

Question 4

What are the characteristics of Restrictive – Diffuse - Interstitial Lung Disease?

Answer 4

•Reduced Lung Compliance

• Stiff Lungs

•Low FEV1 & Low FVC but FEV1/FVC normal ratio

•

•Reduced Gas Transfer (Tco or Kco)

-Diffusion abnormality

•Ventilation/Perfusion Imbalance

When small airways affected by pathology

Question 5

Is there airflow limitation in restrictive lung disease?

Answer 5

NO

Question 6

What are the clinical presentations for restrictive lung disease?

Answer 6

Question 7

Which one is Normal? Emphysema? Interstitial Lung Disease?

Answer 7

Question 8

What are the outcomes of Parenchymal (Interstitial) Lung Injury?

Answer 8

Acute inflammation (can develop into chronic response in rare circumstances) or Chronic inflammation

Question 9

What are the three outcomes of Chronic response?

Answer 9

Question 10

Which Chronic restrictive disease is most likely to develop end - stage honeycomb lung?

Answer 10

Usual Interstitial Pneumonitis

Question 11

What does DAD stand for?

Answer 11

Difuse alveolar damage

Question 12

What is DAD asociated with?

Answer 12

Question 13

What are the exudative stages of DADS?

Answer 13

Edema and Hyaline membranes

Edema - Vessels become massively leaky - moreso than in a normal response

Hyaline membranes - lots of proteins

Question 14

What are the proliferative stages of DADS?

Answer 14

Question 15

What are the histological features of DADS?

Answer 15

Question 16

What is the commonest interstitial lung disease that you will encounter?

Answer 16

Sarcoidosis

Question 17

Apart from sarcoidosis what is the other granulomatous respnse?

Answer 17

Hypersensitivity pneumonitis

Question 18

What is the histopathology of sarcoidosis?

Answer 18

Question 19

Why is sarcoidosis called multisystem?

Answer 19

Involves many organs

Question 20

Do most patients with sarcoidosis reach end stage fibrotic lung disease?

Answer 20

No ???

Question 21

What is the presentation of sarcoidosis?

Answer 21

Question 22

What is the diagnosis of sarcoidosis?

Answer 22

Question 23

What is ACE?

Answer 23

A converting enzyme, converts angiotensin 1 to angiotensin 2.

Angiotensin II helps increase blood pressure by causing small blood vessels in the body to tighten or narrow.

Doctors most often use the ACE level test to monitor a disease called sarcoidosis. This condition causes inflammatory cells called granulomas to form in the body, leading to organ inflammation.

The granulomas associated with sarcoidosis increase the amount of ACE in the blood.

Question 24

What are the hypersensitivity pneumonitis antiges?

Answer 24

Question 25

What is the accute presentation for Hypersensitivity Pneumonitis?

Answer 25

Question 26

What is the chronic presentation of Hypersensitivity pneumonitis?

Answer 26

Question 27

What type of hypersensitivity causes Hypersensitivity Pneumonitis?

Answer 27

•Immune complex mediated combined Type III and Type IV Hypersensitivity reaction

Question 28

Describe the granulomata in Hypersensitivity Pneumonitits

Answer 28

•Soft centriacinar epithelioid granulomata, causing interstitial pneumonitis

Question 29

Hypersensitivty pneumonitis is said to cause Bronchiolitis obliterans, what does this mean?

Answer 29

Inflammatory obstruction of bronchioles, these bronchioles become damaged and ingflamed by chemical particles or respiratory infections. Features extensive scarring that blocks airways.

Question 30

What are the causes of Usual interstitial pneumonitis?

Answer 30

Connective tissue diseases - •scleroderma and rheumatoid disease Drugs Asbestos Viruses Idiopathic/cryptogenic reasons

Question 31

What is cryptogenic fibrosing alveolitis?

Answer 31

Old fashioned name for UIP

Question 32

Describe the interstitium of UIP?

Answer 32

Patchy chronic inflammatino Type 2 pneumocytes hyperplasia Smooth muscle and vascular proliferation Proliferating fibroblastic foci

Question 33

What are Proliferating Fibroblastic Foci?

Answer 33

Nodules of fibrous tissue in the walls of the alveoli, reflect the severity of the disease

Question 34

Who usually suffers from Idiopathic Pulmonary Fibrosis?

Answer 34

Question 35

What is the pathology of Idiopathic Pulmonary Fibrosis?

Answer 35

UIP

Question 36

What is the clinical presentation of Idiopathic Pulmonary Fibrosis?

Answer 36

Question 37

What is the prognosis for Idiopathic Pulmonary Fibrosis?

Answer 37

Usually dead within 5 years

Question 38

What will you see in the ches X-ray for someone with Idiopathic Pulmonary Fibrosis?

Answer 38

•CXR : Basal/Posterior, Diffuse infiltrates, Cysts, ‘ Ground Glass ’

Question 39

What is UIP Basal and posterior fibrosis with honeycombing often complicated with?

Answer 39

Peripheral adenocarcinoma

Question 40

Describe the airway flow in interstitial lung disease

Answer 40

Normal air flow, diffusion is altered

Question 41

What is normal PaO2 and PaCO2?

Answer 41

Question 42

What is type 1 and type 2 respiration failure?

Answer 42

Question 43

What are the 4 abnormal states associated with Abnormal pulmonary gas exchange?

Answer 43

Alveolar hypoventilation Shunt Ventilation / Perfusion Imbalance Diffusion Impairment

Question 44

What is the resut of alveolar hypoventilation on PACO₂ and PAO₂ ?

Answer 44

Hypoventilation increases the PACO2 and therefore decreases PaCO2 Increased PACO2 takes up space in the alveoli and therefore causes PAO2 and PaO2 to fall

Question 45

How can you correct a fall in PaO2 due to hypoventilation?

Answer 45

Raising the FIO2

Question 46

What is the commones cause of hypoxaemia clinically?

Answer 46

V/Q mismatch

Question 47

Why is normal V/Q ration 0.8?

Answer 47

•Normally breath 4 l/min. CO is 5 l/min so normal V/Q is 4/5 or 0.8

Question 48

How can you treat hypoxaemia due to low V/Q?

Answer 48

Increase in FIO2

Question 49

Will Interstitial lung disease affect CO2 levels?

Answer 49

Not usally becuase CO2 diffuses 20 times faster than O2

Question 50

How does diffusion impairment affect diffusing speed of oxygen?

Answer 50

•Diffusion impairment means it takes LONGER for blood and alveolar air to equilibrate, particularly for oxygen

Question 51

What is equilibration time for patients with diffusino impairment?

Answer 51

May take as long as 0.75 seconds - the same time as capillary transit time. Normally the equillibration takes 0.25 seconds.

Question 52

Why does diffusion impairment result in a fall in Pa O2 during exercise?

Answer 52

Capillary transit time decreases during exercise, less time for equillibration.

Question 53

Why don't we have 100% haemoglobin saturation?

Answer 53

Because we have a 2-4% shunt

Question 54

When do we see a pathological shunt?

Answer 54

Alveolar ventilatino malformations, congenital heart disease and _pulmonary disease_

Question 55

Does large shunt respond well to increase in FIO₂?

Answer 55

No, blood leaving normal sections of the lung is already 98% saturated