Pleural effusion

Question 1

What are the two types of pleural effusion?

Answer 1

Exudative - high protein content >30g/L

Transudative - lower protein count <30g/L

Question 2

Exudative causes of pleural effusion

Answer 2

• Related to inflammation, resulting in protein leaking out of tissues into the pleural space

Lung cancer
Pneumonia 
PE
TB
RA and other connective tissue diseases e.g. SLE

Question 3

Transudative causes of pleural effusion

Answer 3

Congestive cardiac failure

Hypoalbuminaemia

Hypothyroidism

Meig’s syndrome - right sided pleural effusion with ovarian malignancy

Question 4

Presentation of pleural effusion

Answer 4

SOB
Dry cough
Pleuritic chest pain

Dullness to percussion over the effusion
Reduced breath sounds

Tracheal deviation away from the effusion if it is massive

Question 5

Investigations in suspected pleural effusion

Answer 5

CXR
Pleural fluid aspiration

Bloods - FBC, U&Es, CRP, LFTs, LDH (LDH for light’s criteria)
Sputum culture - if suspect pneumonia

Question 6

CXR findings in pleural effusion

Answer 6

Blunting of the costophrenic angle

Fluid in lung fissures

Larger effusions will have a meniscus

Tracheal and mediastinal deviation away from the effusion if it is massive

Question 7

What criteria can be used to distinguish between transudative and exudative if it is borderline?

Answer 7

Light’s criteria (for 25-35 g/L range of protein)

Exudative likely if any of:

• Pleural fluid protein/serum protein >0.5
• Fluid LDH/Serum LDH >0.6
• Pleural fluid LDH >2/3 upper limit of normal serum LDH

Question 8

Treatment of pleural effusion

Answer 8

Treat underlying cause

Conservative management - appropriate in small effusions (likely to resolve when treating the underlying cause)

Pleural aspiration - can temporarily relieve pressure but the effusion may recur (especially in malignancy or if underlying cause not treated) so may need to be repeated
- Insert need just above upper border of rib to avoid NV bundle

Chest drain - can be used to drain the effusion and prevent it recurring

Question 9

What is empyema?

Answer 9

When there is an infected pleural effusion

Pleural aspiration will show pus, pH <7.2, low glucose and high LDH

Question 10

Treatment of empyema?

Answer 10

Chest drain to remove pus

Antibiotics

Question 11

Where is a chest drain inserted?

Answer 11

In the safe triangle

Borders:

• Lateral edge of pec major
• 5th intercostal space
• Lateral edge of latissimus
• Base of axilla