Pleural effusion

Question 1

Define pleural effusion.

Answer 1

Fluid in the pleural space

Question 2

How are effusions divided? What are they?

Answer 2

According to their protein concentration.
Transudates = < 25g/l
Exudates = > 35g /l

Question 3

What are the causes of transudate effusion where protein concentration < 25g/l ?

Answer 3

1) Increased venous pressure due to cardiac failure, constrictive pericarditis, fluid overload
2) Hypoproteinaemia due to cirrhosis, nephrotic syndrome, malabsorption
3) Hypothyroidism
4) Meig’s syndrome - right pleural effusion and ovarian fibroma

Question 4

What are the causes of exudative effusion where protein concentration > 35g/l ?

Answer 4

Due to increased leakiness of pleural capillaries secondary to infection, inflammation, malignancy
Infection: pneumonia, TB
Inflammation: Pulmonary infarction, rheumatoid arthritis, SLE
Malignancy: Bronchogenic carcinoma, malignant metastases, lymphoma, mesothelioma, lymphangitis, carcinomatosis

Question 5

What are the features of pleural effusion on CXR?

Answer 5

1) Blunting of the costophrenic angles - small effusions
2) Water-dense shadows with concave upper borders - large effusion
3) Completely flat horizontal upper border - pleural effusion and pneumothorax
4) Collapse of the adjacent lung due to large volume pleural effusion
5) Mediastinal shift - large effusion

Question 6

What are the symptoms of pleural effusion?

Answer 6

Asymptomatic
Dyspnoea
Pleuretic chest pain

Question 7

What investigations are carried out for pleural effusion?

Answer 7

CXR
Ultrasound - for the presence of pleural fluid
Diagnostic aspiration

Question 8

What are the signs of pleural effusion on examination?

1. Chest expansion
2. Percussion
3. Auscultation

Answer 8

Chest expansion = Decreased expansion
Percussion = Decreased, (Stony) dull percussion note
Auscultation = Reduced air entry, reduced vocal resonance,
May be bronchial breathing at the top of an effusion