Unilateral Pleural Effusion

Question 1

What causes it?

Answer 1

• Pleural effusion = fluid in pleural space. Effusions can be divided by their protein concentration into transudates (35g/L).
• Blood in pleural space = haemothroax.
• Pus in pleural space = empyema
• Chyle (lymph with fat) = chylothorax.
• Blood and air = haemopneumothorax.

Question 2

What risk factors are there (and how can they be reduced)?

Answer 2

• Having one of a number of existing medical conditions. The following can cause pleural effuision.
• Congestive heart failure, kidney failure, malignancy, infection, PE, hypoalbuminaemia, cirrhosis, trauma.

Question 3

How does it present?

Answer 3

Symptoms
- Asymptomatic – or dyspnoea, pleuritic chest pain.

Signs

• Decreased expansion
• Stony dull percussion note
• Diminished breath sounds occur on affected side.
• Tactile vocal fremitus and vocal resonance are ↓ (inconsistent and unreliable).
• Above effusion, where lung is compressed, there may be bronchial breathing.
• With large effusions there may be tracheal deviation away from the effusion.
• Look for aspiration marks and signs of associated disease: malignancy (cachexia, clubbing, lymphadenopathy, radiation marks, mastectomy scar); stigmata of chronic liver disease; cardiac failure; hypothyroidism; rheumatoid arthritis; butterfly rash of SLE.

Question 4

Which other conditions may present similarly?

Answer 4

• A lot of respiratory disorders. Differentiated by CXR.

Question 5

How would you investigate the patient?

Answer 5

CXR: small effusions blunt the costophrenic angles, larger ones seen as water-dense shadows with concave upper borders. A completely flat horizontal upper border implies that there is also a pneumothorax.

Ultrasound: useful in identifying the presence of pleural fluid and in guiding diagnostic or therapeutic aspiration.

Diagnostic aspiration – percuss upper border of pleural effusion and choose site 1 or 2 intercostal spaces below it. Aspiration etc… Clinical chemisty (protein, glucose, pH, LDH, amylase), bacteriology (microscopy and culture, auramine stain, TB culture), cytology and if indicated, immunology (rheumatoid factor, ANA, complement).

Question 6

What treatment/s would you consider? What risks and benefits of treatment are there?

Answer 6

• Drainage
• Pleurodesis – with tetracycline, bleomycin, or talc – may be useful in recurrent effusions.
• Intra-pleural streptokinase of no benefit.
• Surgery – required if persistent collections and increasing pleural thickness.