Pleural Effusion (pathology)

Question 1

What is a pleural effusion?

Answer 1

Collection of fluid in pleural space

- Imbalance between production & absorption (by pleural lymphatics in parietal pleura)

Question 2

What does a pleural effusion of exudate indicate?

Answer 2

Exudate = inflammatory 
•	Cancer (lung or not)
•	Pneumonia (effusion, empyema)
•	TB 
•	Rheumatoid arthritis

Question 3

What does a pleural effusion of transudate indicate?

Answer 3

non inflammatory (shifting of fluid)
•	Cardiac failure 
•	Liver failure 
•	Renal failure 
•	Hypoalbuminemia

Question 4

Investigations for pleural effusion

Answer 4

-US=more sensitive than CXR- mark site for aspiration
-CXR – first test but requires 100/200 ml for visualisation
Restrictive on pulmonary function
-CT thorax- complex effusion, visualise pleura and loculations, vascular + mediastinal structures

Pleural fluid analysis
- Aspiration
- Inspect fluid (pus or blood)
pH, biochemistry, microbiology, cytology

Question 5

Management of pleural effusion

Answer 5

• pH < 7.2= suggest pneumonia -> chest drain
• transudate-> treat underlying cause (heart/renal failure)- no CT
• exudate-> treat infection/ further imaging + biopsy if cause not identified