Pleural effusion

Question 1

What is a plerual effusion?

Also define haemothorax, chylothorax, empyema, haemopneumothorax.

Answer 1

Fluid in the pleural space.

1. Transudate effusions have <25g/L of protein concentration
2. Exudate effusions have >35g/L of protein concentration

Haemothorax - blood in pleural space

Chylothorax - chyle (lymph with fat) in pleural space

Empyema - pus in the pleural space

Haemopneumothorax - blood & air in pleural space

Question 2

What are the causes of pleural effusions?

Answer 2

Transudates;

• Inc venous pressure
  
  • Cardiac failure, constrictive pericarditis, fluid overload)
• Hypoproteinaemia
  
  • Cirrhosis, nephrotic syndrome, malabsorption
• Also; hypothyroidism, Meigs’ syndrome (right pleural effusion & ovarian fibroma)

Exudates;

• Inc leakiness of pleural capillaries secondary to;
  
  • Infection, inflammation, malignancy
  • eg, pneumonia, TB, pulmonary infarction, rheymatoid arthritis, SLE, bronchogenic carcinoma, malignant metastases, lymphoma, mesothelioma, lymphangitis, carcinomatosis

Question 3

What are the symptoms & signs of pleural effusion?

Answer 3

Symptoms;

• None
• Dyspnoea
• Pleuritic chest pain

Signs;

• ↓ expansion & breath sounds
• Dull percussion, ↓vocal resonance, ↑tactile vocal fremitus
• Bronchial breathing above effusion due to compression
• Tracheal deviation away from large effusion
• Look for;
  
  • Aspiration marks
  • Signs of disease (malignancy, stigmata of CLD, cardiac failure, hypothyroidism, rhymatoid arthritis, butter-fly rash of SLE)

Question 4

What investigations would you perform for pleural effusion?

Answer 4

• CXR
  
  • Blunt costophrenic angles (small)
  • Water-dense shadows with concave upper borders (large)
  • Horizontal upper border implies pneumothorax also
• Ultrasound
  
  • Identifies presence of pleural fluid
  • Guides diagnostic/ therapeutic aspiration
• Diagnostic aspiration
  
  • Percuss upper border of pleural effusion and choose site 1/2 intercostal spaces below (not in abdo!)
  • Infiltrate down to pleura with 5-10mL of 1& lidocaine (anesthetic/ antiarrhythmic)
  • Attach 21G needle to syringe & insert just above border of rib
  • Draw 10-30mL of pleural fluid
  • Send for
    
    • Clinical chemistry; protein, glucose, pH, LDH, amylase
    • Bacteriology; microscope & culture, auramine stain, TB culture
    • Cytology
    • Immunology (if indicated); rheumatoid factor, ANA, complement
• Pleural biopsy (if fluid analysis inconclusive)
  
  • Abrams’ needle

Question 5

How do you manage a pleural effusion?

Answer 5

• Drainge
  
  • If symptomatic
  • Slowly (<=2L/24hr)
• Pleurodesis
  
  • With tetracycline, bleomycin or talc
• Surgery
  
  • Persistent collections & inc pleural thickness