Pleural Fluid Analysis

Question 1

What are some causes of transudative fluid effusions?

Answer 1

Congestive heart failure, liver cirrhosis, severe hypoalbuminaemia, nephrotic syndrome, hypothyroidism

Question 2

What are some causes of exudative pleural effusions?

Answer 2

Malignancy, infection, trauma, PE, TB

Question 3

What are the protein levels in exudative and transudative pleural effusions?

Answer 3

Transudative < 30 g/L
Exudative > 30g/L

Question 4

What is the Light’s criteria

Answer 4

More accurate way of diagnosing an exudative fluid. Needs to have one of the following:
Ratio of pleural fluid to serum protein > 0.5
Ratio of pleural fluid to serum LDH > 0.6
Fluid LDH greater than 2/3rd of the upper limit of normal serum value

Question 5

The following colours of pleural fluid suggest what?
- Purulent,
- Milky
- Straw-coloured

Answer 5

Purulent = empyema
Milky = Chylothorax
Straw coloured and smelling of amonia = urinothorax

Question 6

What is the fluid analysis of a complex parapneumonic effusion?

Answer 6

LDH > 1000
Glucose < 2.2
pH <7.2
On ultrasound there will be lots of septae

Question 7

What are some other causes of:
High LDH
Low glucose

Answer 7

High LDH - malignancy, rheumatoid pleuritis.
Low glucose - rheumatoid pleuritis, TB, malignancy

Question 8

Lymphocytosis fluid is suggestive of?

Answer 8

TB, sarcoidosis or malignancy

Question 9

Neutrophil dominant fluid is suggestive of?

Answer 9

Empyema or PE