Pleural effusion

Question 1

How are exudate and transudate distinguished?

Answer 1

Protein content: exudate has >30g/L protein, transudate has <30g/L protein

Question 2

Causes of an exudative pleural effusion? (5)

Answer 2

Infection (e.g. TB, pnuemonia)
Connective tissue disease (e.g. RA, SLE)
Neoplasia
Pancreatitis
Pulmonary embolism

Question 3

Causes of a transudative pleural effusion? (4)

Answer 3

Heart failure
Hypoalbuminaemia
Hypothyroidism
Meig’s syndrome

Question 4

How is a suspected pleural effusion investigated?

Answer 4

PA chest X ray

Ultrasound-guided pleural aspiration

Question 5

Needle gauge used for pleural aspiration?

Answer 5

21G

Question 6

What are Light’s criteria used for?

Answer 6

To determine whether an effusion is an exudate when protein content is between 25-30g/L

Question 7

Frankly purulent effusion indicates…?

Answer 7

Empyema

Question 8

Milky, opalescent fluid indictaes…?

Answer 8

Chylothorax

Question 9

Characteristic pleural fluid findings:

a) low glucose (2)
b) raised amylase (2)
c) heavy blood staining (3)

Answer 9

a) RA, TB
b) pancreatitis, oesophageal perforation
b) mesothelioma, PE, tuberculosis

Question 10

An exudative effusion would prompt what subsequent investigations?

Answer 10

Most likely CT chest- look for malignancy/TB

Question 11

A transudative effusion would prompt what subsequent investigations?

Answer 11

Echo- looking for heart failure

Liver imaging e.g. USS- looking for cirrhosis