Restrictive Pulmonary Diseases

Question 1

What can be causes or restrictive pulmonary disease?

Answer 1

Lung - interstitial diseases
Pleura - pneumothorax, effusion, mesothelioma
Bone - thoracotomy, rib fractures, kyphoscoliosis
Muscle - amyotrophic lateral sclerosis
Other - pregnancy, obesity

Question 2

What is the definition of restrictive lung disease, and how is it diagnosed?

Answer 2

FVC < 80%

Spirometry to assess restriction

Question 3

What are the main causes of lung-related restrictive lung disease?

Answer 3

Sarcoidosis
Hypersensitivity pneumonitis
Diffuse alveolar syndrome
Idiopathic pulmonary fibrosis

Question 4

What is the pathology of diffuse alveolar syndrome?

Answer 4

Exudate in lung interstitial space
Hyaline membranes formed around alveoli
Inflammation and fibrosis

Question 5

What can cause diffuse alveolar syndrome?

Answer 5

Infection
Chemicals
Drugs
Trauma
Radiation 
Autoimmune disease

Question 6

What are some symptoms associated with sarcoidosis?

Answer 6

Sometimes none 
Erythema nodosum
Other skin lesions
Arthralgia
Hilar lymphadenopathy
Respiratory: SoB, cough

Question 7

What is sarcoidosis?

Answer 7

Granulomatous disease of unknown aetiology

Question 8

What is a histological hallmark of sarcoidosis?

Answer 8

Non caseating, non necrotising granuloma

Question 9

What are the main investigations for sarcoidosis?

Answer 9

History + exam
CXR
Bloods (ACE, calcium)
Urine analysis
Eye test
TB skin prick 
ECG
Bronchoscopy +/- biopsy

Question 10

What is used to obtain a biopsy for sarcoidosis?

Answer 10

Bronchoscopy
Endobronchial ultrasound
VATS

Question 11

What is the main management for sarcoidosis?

Answer 11

Depends on severity
No symptoms - no treatment, self limiting
Mild symptoms - topical steroids
Severe/resp symptoms - systemic steroids

Question 12

What is the prognosis for sarcoidosis?

Answer 12

Normally good, but depends on stage of disease

Question 13

What is the prevalence and epidemiology of sarcoidosis?

Answer 13

Young adults <40, often women

Worldwide occurrence, more common in temperate countries

Question 14

What is hypersensitivity pneumonitis?

Answer 14

Type 3/4 hypersensitivity mediated disease

Caused by antigens leading to inflammation and fibrosis of lung interstitium

Question 15

What causes hypersensitivity pneumonitis?

Answer 15

Antigens from environment
Different names depending on antigen:
Bird fancier’s lung, farmer’s lung etc

Question 16

What investigations should be done to diagnose hypersensitivity pneumonitis?

Answer 16

HISTORY!!
CXR
Bloods

Question 17

What is the best treatment for hypersensitivity pneumonitis?

Answer 17

Finding and treating underlying cause (antigen)

Otherwise steroids

Question 18

Where in the lung is hypersensitivity pneumonitis likely to occur?

Answer 18

Upper lobes

Question 19

What can be some symptoms of hypersensitivity pneumonitis?

Answer 19

Acute: fever, chills, malaise, cough, crackles and wheeze

Chronic: progressive SoB, crackles and wheeze, insidious, malaise/weight loss/reduced lung function over time

Question 20

What characterises hypersensitivity pneumonitis?

Answer 20

Centriacinar granulomas

Interstitial pneumonitis

Question 21

What is usual interstitial pneumonitis?

Answer 21

A range of diseases which cause severe fibrosis and loss of lung function

Question 22

What is a relatively common type of usual interstitial pneumonitis?

Answer 22

Idiopathic pulmonary fibrosis

Question 23

What are some signs/symptoms of idiopathic pulmonary fibrosis?

Answer 23

Clubbing, basal crackles
Chronic cough
Increasing SoB
May have unsuccessfully been treated for LVF or infection
Malaise, weight loss

Question 24

What organs are most commonly involved in sarcoidosis?

Answer 24

Lymph nodes
Lung 
Liver
Spleen
Skin/eyes/skeletal muscle/salivary glands 
Bone marrow

Question 25

What is the best management for idiopathic pulmonary fibrosis?

Answer 25

Antifibrotic treatment Anti-angiogenic treatment (limited) Lung transplant

Question 26

What is the prevalence of idiopathic pulmonary fibrosis?

Answer 26

Commoner in men | Age over 50/60

Question 27

What are some investigations for idiopathic pulmonary fibrosis?

Answer 27

CXR and/or CT scan Pulmonary function tests (TCO and KCO for gas transfer) Bloods

Question 28

What is the main cause for hypoxaemia in interstitial lung diseases and why?

Answer 28

Diffusion impairment due to thicker interstitial space

Question 29

What type of respiratory failure does hypoxaemia in interstitial lung diseases lead go and why?

Answer 29

Resp failure type 1 | Thicker interstitium impairs O2 diffusion, but not CO2 diffusion as it’s more soluble

Question 30

How can hypoxaemia due to diffusion impairment be corrected?

Answer 30

By increasing FIO2

Question 31

Why are patients with interstitial lung disease more likely to suffer from SoB during exercise?

Answer 31

Because during exercise O2 has less time to diffuse through blood/air barrier, and if interstitium is thicker it takes longer for diffusion to occur

Question 32

Which interstitial lung disease is more likely to cause end stage lung disease (honeycomb lung)?

Answer 32

Idiopathic pulmonary fibrosis

Question 33

What characterises the histopathology of idiopathic pulmonary fibrosis?

Answer 33

``` Patchy areas of chronic inflammation Temporal/spatial heterogeneity Lower lobes more affected Pneumocyte type 2 hyperplasia Lots of fibroblasts/collagen deposition Angiogenesis ```

Question 34

What should be looked for in particular in blood tests for sarcoidosis?

Answer 34

Plasma ACE levels | Plasma calcium levels