Pleural effusion

Question 1

What are the types of pleural effusion?

Answer 1

Exudative and Transudative

Question 2

What characterises transudative and exudative pleural effusions?

Answer 2

Protein less than 30g/L in transudate. Over 30g/L in exudate.

Question 3

What is the aetiology transudative pleural effusions? (x4)

Answer 3

• RAISED HYDROSTATIC PRESSURE: congestive heart failure, pericarditis, fluid overload
• LOW ONCOTIC PRESSURE: hypoalbuminemia from liver cirrhosis, nephrotic syndrome, malabsorption
• HYPOTHYROIDISM
• MEIG’S SYNDROME

Question 4

What is the aetiology of exudative pleural effusions? (x4)

Answer 4

• Increased capillary permeability
• Secondary to infection such as pneumonia or TB
• Inflammation such as pulmonary infarct, PE, RA or SLE
• Malignancy

Question 5

What is Light’s criteria for a pleural effusion?

Answer 5

Pleural fluid can be categorized as an exudate if one or more of the following exist: (1) The pleural fluid protein divided by serum protein >0.5; (2) Pleural fluid LDH divided by serum LDH >0.6 and (3) Pleural fluid LDH is more than two-thirds the upper limits of normal serum LDH.