Acute - Pleural effusion

Question 1

Name some transudate causes of pleural effusion.

Answer 1

• Heart failure
• Cirrhosis
• Hypoalbuminaemia (nephrotic syndrome or peritoneal dialysis)
• Less common:
  
  • Hypothyroidism
  • Mitral stenosis
  • PE
• Rare:
  
  • Constrictive pericarditis
  • SVC obstruction
  • Meig’s syndrome - right sided pleural effusion, ovarian cancer, ascites

Question 2

Name some causes of exudative effusions.

Answer 2

• Malignancy
• Infections - pneumonia, TB, HIV (Kaposi’s sarcoma)
• Less common
  
  • Inflammatory - rheumatoid arthritis, pancreatitis, Dressler syndrome
• Rare
  
  • Yellow nail syndrome
  • Drugs

Question 3

What is the difference between transudate and exudate?

Answer 3

• Transudate - <30g/L protein
• Exudate - >30g/L protein

Question 4

How does a pleural effusion present?

Answer 4

Symptoms:

• Asymptomatic
• Dyspnoea
• Pleuritic chest pain

Signs:

• Decreased chest expansion
• Stony dull percussion note and diminished breath sounds on affected side
• Above the effusion, where the lung is compressed, there may be bronchial breathing
• With large effusions there may be tracheal deviation away from effusion
• Look for aspiration marks
• Look for signs of associated disease
  
  • Malignancy – cachexia, clubbing lymphadenopathy, masectomy scar
  • Stigmata of chronic liver disease
  • Cardiac failure
  • Hypothyroidism
  • Malar rash of lupus

Question 5

What initial investigations would be requested in a patient presenting with a pleural effusion?

Answer 5

A-E assessment

• B
  
  • ABG if O2 requirement
  • PA CXR
  • USS
• C
  
  • Bloods - FBC, U&Es, LFTs, TFTs, CRP, Bone profile, LDH, Clotting
  • ECG

Question 6

What further investigation might be required in a pleural effusion with no obvious cause?

Answer 6

• Transudate
  
  • ECHO - heart failure?
  • TFTs - hypothyroidism
• Exudate
  
  • CT CAP - malignancy?

Question 7

What are the typical CXR findings in pleural effusion?

Answer 7

• Blunting of the costophrenic angles
• Dense, homogeneous opacity in lower zone
• Upper border curved (meniscus) - a flat horizontal upper border implies there is also a Pneumothorax
• Cannot see outline of diaphragm

Question 8

How are pleural effusions initially managed?

Answer 8

USS-guided pleural aspiration - fluid sent for pH, protein, LDH, cytology and microbiology

Question 9

When is Light’s criteria required?

Answer 9

Use Light’s criteria if 25-35g/L pleural protein:

Exudate if one or more of the following:

• Pleural fluid/serum protein>0.5
• Pleural fluid/serum LDH>0.6
• Pleural fluid LDH>2/3 of upper limit of normal

Question 10

When is a chest drain required?

Answer 10

Do not insert a chest drain unless the diagnosis is well established (e.g. metastatic lung cancer) otherwise draining all fluid off may hinder the opportunity to obtain pleural biopsies. The only indication for urgent chest drain insertion for an effusion would be underlying empyema (pH <7.2 or visible pus on aspirate)

Question 11

What should be considered if a patient has low glucose in their pleural fluid?

Answer 11

rheumatoid arthritis

tuberculosis

Question 12

What should be considered if a patient has raised amylase in their pleural fluid?

Answer 12

pancreatitis

oesophageal perforation

heavy blood staining - mesothelioma, pulmonary embolism, TB