Restrictive lung disease

Question 1

Restrictive lung diseases

Answer 1

Pulmonary conditions that reduces lung volumes:

TLC
FRC
FVC

Conditions prevent the lung from expanding to normal volumes.

Question 2

Lung interstitium

Answer 2

The interstitial space- between cells.

Intralobular- location of the capillaries which surround alveoli.

Interlobular- surround secondary lobules. Location of lymphatics and veins.

Question 3

Interstitial lung disease

Answer 3

Condition characterised by abnormal interstitium due to:
Inflammation
Scarring

There causes:
Environmental exposure
Idiopathic
System inflammatory diseases

Question 4

Environmental exposure causes of ILD

Answer 4

Hypersensitivity pneumonitis

Occupational lung disease

Question 5

Hypersensitivity pneumonitis

Answer 5

A type of ILD causes by the lungs having an excessive immune response to mould or bird proteins, usually.

APCs present the particles and activates T cells.

T cells activate macrophages to form granulomas and also inflames the bronchioles and intralobular septa.

Question 6

Occupational lung disease

Answer 6

Also called pneumoconiosis

A type of ILD caused by exposure to specific substances associated with certain occupations:

Silicosis- silica exposure
Coal miners lung- coal dust exposure
Asbestosis- asbestos exposure.

Question 7

Silicosis

Answer 7

Pneumoconiosis caused by excess inhalation of silica.

This causes nodular fibrosis - progressive massive fibrosis

Question 8

Asbestosis

Answer 8

Pneumoconiosis caused by inhalation of asbestos.

The asbestos fibres form honeycomb cysts which can be seen on CT scans.

Pleural plaques can occur and turn into mesothelioma tumours.

Question 9

Idiopathic pulmonary fibrosis (IPF)

Answer 9

A common ILD

Usually present in older people, over 50.

Commonly seen in individuals who have smoked, but the mechanism is still not understood.

Forms honeycomb cysts seen in CT scans and affects the lower and peripheral aspects of the lungs.

There isn’t that much inflammation, instead there are many fibroblasts that makes XS collagen- type III.

Question 10

Resorptive atelectasis

Answer 10

Collapse of alveoli due to endobronchial obstruction.

Air becomes trapped inside the alveoli- when left too long, the gases are absorbed into the blood.

This deflates the alveoli, due to the loss of its distending pressure.

Question 11

Compressive atelectasis

Answer 11

Alveoli collapse due to the formation of a pleural process or lung mass.

This pushes the lung, forcing it to collapse.

Question 12

Systemic inflammatory diseases that cause ILD

Answer 12

Autoimmune disease ILD

Sarcoidosis

Question 13

Coal miner’s lung

Answer 13

A type of pneumoconiosis cause by coat dust particle inhalation.

The particles are very fine and enter alveoli, where they are engulfed by macrophages.

This triggers inflammation which can can trigger massive fibrosis.

Coal dust stays in the lung forever.

Question 14

Pleural effusion

Answer 14

IL of fluid cycles the pleural cavity every day.

When the fluid is >25mL, this is a pleural effusion.

This occurs when influx of fluid exceeds efflux of fluid.

Question 15

Influx of pleural fluid

Answer 15

Methods in which pleural fluid enters the pleural space:

Capillary leak- high HP/ very low oncotic pressure

Fluid from pulmonary interstitium crosses visceral pleura.

Peritoneal fluid enters via rents in the diaphragm into pleural space.

Question 16

Efflux of pleural fluid

Answer 16

Method of pleural fluid leaving the pleural space:

Resorptive stoma in the pleura allows fluid to drain into lymphatics.

Question 17

Percussion of a chest with pleural effusion

Answer 17

This will show dullness at the base due to fluid filling the base of the lung.

Question 18

Causes of pleural effusion

Answer 18

Congestive heart failure

Liver disease with portal HT and cirrhosis

Low albumin states- nephrotic syndrome

Infections: TB, empyema, parasites

Malignancies

Pleurisy

Cylothorax

Question 19

Transudative effusion

Answer 19

Most common type of pleural effusion where fluid is mainly water.

It usually arises from a non-pleural disease process.

The effusion will resolve if primary problem is fixed

Question 20

Exudative effusion

Answer 20

A pleural effusion that contains protein rich fluid in the pleural space.

This will not resolve itself, so always needs to be drained.

Question 21

Conditions that cause altered pleural membrane permeability leading to exudative pleural effusions.

Answer 21

Infection

Cancer

Autoimmune disease

Question 22

Conditions that cause altered capillary membrane permeability leading to exudative pleural effusions.

Answer 22

Pneumonia- has a vasodilatory effect

Question 23

Mechanisms of exudative effusions

Answer 23

Entry of tumour cells via lymphatics- cancer

Thoracic duct injury- spills lymphatic material into pleural space.

Penetrating trauma- causes blood in the pleural space

Question 24

Tube thoracostomy

Answer 24

Placement of a chest tube to usually drain a exudate pleural effusion.

Question 25

Thoracentesis

Answer 25

Procedure that involves using a needle to sample or drain a pleural effusion.

No more than 1.5L of fluid should be drained to avoid re-expansion pulmonary oedema.

Question 26

Studies of pleural effusion fluid

Answer 26

pH

Cell counts

Microbial stain + culture studies

Cytopathology- identification of cancer cells

Protein, LDH, glucose and cholesterol levels.

Triglyceride levels

Question 27

Light’s criteria for determining exudative effusion

Answer 27

Effusion is exudative IF:

Protein levels in pleura/ Protein levels in serum > 0.5

Lactate dehydrogenase level in pleural / LDH level in serum > 0.6

LDH in pleura > 2/3 upper limit of normal in serum.

Question 28

Empyema

Answer 28

Infection in pleural cavity which causes collection of pus in the cavity.

Requires complete evacuation to prevent development of fibrous visceral pleural peel —> leads to a trapper lung.

Question 29

Parapneumonic effusion

Answer 29

Effusion caused by pneumonia.

Indications:
Sterile inflammation
pH> 7.2
Small, free flowing fluid.

This effusion usually heals as the pneumonia heals.

Question 30

Haemothorax

Answer 30

Blood in pleural cavity

Indications:
Pleural fluid hematocrit> 50% of blood HCT.

Requires complete evacuation to prevent development of fibrous visceral pleural peel —> leads to a trapper lung.

Question 31

Hepatic hydrothorax

Answer 31

Occur when cirrhotic fluid transverses across the diaphragm, via rents, into the pleural space.

Question 32

Chylothorax

Answer 32

Pleural effusion where triglyceride levels are greater than 110 mg/dL in the pleural fluid.

Triglycerides drain from cisternal cyli, via thoracic duct.

Question 33

Spontaneous pneumothorax

Answer 33

Collection of air in the pleural cavity.

This is causes by formation of small air sacs (blebs) which rupture and leak air into the pleural space.

Question 34

Traumatic pneumothorax

Answer 34

Collection of excess air in the pleural space caused by trauma that is:
Penetrating 
Procedural
Pressure (barotrauma)
Ribe fracture.

Question 35

Weakness and myopathic chest wall diseases

Answer 35

Degenerative spinal disease

Myasthenia gravis

Global weakness- muscle weakness

Question 36

Degenerative spinal disease

Answer 36

Conditions that affect the chest wall structure and can cause restrictive lung disease:

Motor neurone disease

Polio

Question 37

Myasthenia gravis

Answer 37

Serious skeletal muscle weakness

This causes chest wall disease that implicates ventilation- restrictive lung disease

Question 38

Skeletal and connective tissue restrictions that cause chest wall diseases

Answer 38

Kyphoscoliosis

Extensive burns around the chest wall.

Question 39

Kyphoscoliosis

Answer 39

Abnormal curving of the spine at both the coronal and sagittal plane.

This distorts the chest wall and causes restrictive lung disease.