Pleural Disease - Pleural Effusion

Question 1

What is a mesothelial layer?

Answer 1

Membranes formed by simple squamous epithelium

Question 2

What is the pleura made of?

Answer 2

Single layer of mesothelial cells

Question 3

What is the pressure in the pleural cavity?

Answer 3

-0.66kPa

Question 4

What is the pleural cavity lubricated by?

Answer 4

2-3ml of pleural fluid

Fluid has high turnover

Question 5

How does pleural fluid absorb into blood?

Answer 5

Due to plasma osmotic pressure

Question 6

How does fluid move into the pleural cavity?

Answer 6

Via positive systemic and pulmonary arterial pressures pushing it into the negative pressure cavity

Question 7

What are structures that can be damaged in a pleural procedure?

Answer 7

Subclavian vein/arteries
Liver
Kidney’s
Spleen

Question 8

What is pleural effusion?

Answer 8

Abnormal collection of fluid in the pleural cavity

Question 9

What are the two types of pleural effusion?

Answer 9

Transudates - fluid protein <30g/l

Exudates - fluid protein >30g/l

Question 10

What causes transudates?

Answer 10

Imbalance of hydrostatic forces causes overproduction of fluid and over absorption normally due to altered capillary permeability

Question 11

Are transudates bilateral or unilateral?

Answer 11

Usually bilateral

Question 12

Name a cause of transudate pleural effusion?

Answer 12

LV failure

Question 13

How do exudates make it into the pleural cavity?

Answer 13

Increased permeability of the pleural surface and/or local capillaries, often due to inflammation

Question 14

Are exudates bilateral or unilateral?

Answer 14

Often unilateral

Question 15

Causes of exudates?

Answer 15

Malignancy
Pneumonia or Lung Abscess
Pulmonary embolism

Question 16

Symptoms of a pleural effusion?

Answer 16

Can be asymptomatic
Increasing dyspnoea
Pleuritic chest pain
Dry cough

Question 17

What are the patterns of the pleuritic chest pain for inflammatory causes vs malignancy?

Answer 17

Inflammatory - early pain that may improve as fluid accumulates

Malignancy - pain the gradually keeps getting worse

Question 18

What signs are seen on the affected side of chest during examination?

Answer 18

Reduced chest expansion, breath sounds and vocal resonance

Stony dullness to percussion

Question 19

What other signs are there?

Answer 19

Signs of underlying disease - clubbing, lymphadenopathy, increased JVP

Trachea deviated away from a large effusion - if unchanged may indicate a collapse

Question 20

What investigations can be done?

Answer 20

CxR
CT thorax
Pleural aspiration and biopsy

Question 21

What can a CxR see?

Answer 21

Fluid build up - needs to be over 200ml before it shows

Question 22

What can a CT thorax see?

Answer 22

Can differentiate between malignant and benign diseases

Question 23

What can be noted of the liquid sample taken via aspiration before sending off to lab?

Answer 23

Foul smell - anaerobic empyema

Pus - empyema

Food particles - oesophageal rupture

Blood - malignancy, haemothorax, trauma

Question 24

Treatment for a pleural effusion?

Answer 24

Pleurodhesis

• Fluid must be drained
• Patient at 45 degreed with arm above head
• Drain in 4th intercostal space in mid-axilliary line

Drain no faster than 500ml/hr and drain til dry - check with a CxR

Talc is inserted through a chest tube to cause inflammation then removed after a few hours.

This seals pleural space with scar tissue stopping fluid build up again

Question 25

What should be done if the lung does not re-expand after drainage?

Answer 25

Apply suction

Remove drain due to infection risk