Pleural effusion

Question 1

What are the causes of pleural effusion?

Answer 1

1. Transudates
   - CCF
   - pulmonary embolism
   - nephrotic syndrome
   - cirrhosis
2. Exudates
   - bacterial infection/parapneumonic
   - empyema
   - TB
   - malignancy
   - post pneumonectomy
   - oesophageal perforation
   - Rheumatoid disease/vasculitis
   - Meigs syndrome
3. Haemorrhage
   - trauma
   - iatrogenic injury

Question 2

What would you send a sample of pleural fluid for?

Answer 2

1. LDH
2. Protein
3. Glucose
4. pH
   5 . MC&S
5. Cytology

Question 3

What are Light’s criteria?

Answer 3

To differentiate between transudate and exudate.

Effusion is exudate if one of the following is met:

• Protein effusion to serum ratio >0.5
• LDH effusion to serum ration >0.6
• Effusion LDH >200IU