Pleural Effusion

• A pleural effusion is the accumulation of fluid within the pleural space. A small amount of fluid exists in healthy individuals to lubricate the lungs during movement. Effusions typically have to be over 500 ml before they cause any symptoms.
• • Pleural effusions may be classified as being either a transudate or exudate according to the protein concentration.
  • Effusions with a protein concentration of less than 30 g/L are classified as transudative.
  • Effusions with a protein concentration of more than 30 g/L are classified as exudative.
• Causes of transudative pleural effusions:

  • Heart failure (most common)
  • Hypoalbuminemia - liver disease, nephrotic syndrome, malabsorption
  • Hypothyroidism
  • Meigs' Syndrome
• Causes of exudative pleural effusions:

  • Infection: pneumonia (most common exudate cause), Tuberculosis, subphrenic abscess
  • Connective tissue disease: Rheumatoid arthritis, SLE
  • Neoplasia: lung cancer, mesothelioma, metastases
  • Pancreatitis
  • Pulmonary embolism
  • Dressler's syndrome
  • Yellow nail syndrome
• Pleural effusion clinical features:

  • dyspnoea
  • cough
  • chest pain
  • dullness to percussion
  • reduced breath sounds
  • reduced chest expansion
• Pleural effusion X ray feature:

  • blunting of the costophrenic angle

  
• Lights criteria:

  • Pleural protein: serum protein ratio >0.5
  • Pleural LDH: serum LDH ratio >0.6
  • Pleural LDH >200
• Pleural effusion imaging:

  • PA X-rays
  • Ultrasound - for pleural aspiration
  • Contrast CT - to investigate underlying cause
• Diagnostic aspiration in pleural effusion:

  • Use with ultrasound
  • use a 21G needle with syringe on upper border of ribs
  • take 10-30 ml of fluid
  • send sample for clinical biochemistry - glucose, protein, amylase, LDH
• • Empyema is the collection of pus in the pleural cavity.
  • can occur as a complication of pneumonia, thoracotomy, abscesses (lung, hepatic, or subdiaphragmatic), or penetrating trauma with secondary infection.
  • Presents with yellow or white stinky fluid on pleural tap.
  • Presents with exudate that has pH < 7.2
  • should be completely drained via thoracentesis or tube thoracostomy.
• Pleural infection:

  • All patients with a pleural effusion in association with sepsis or a pneumonic illness require diagnostic pleural fluid sampling
  • If the fluid is purulent or turbid/cloudy a chest tube should be placed to allow drainage
  • If the fluid is clear but the pH is less than 7.2 in patients with suspected pleural infection a chest tube should be placed
• Management of recurrent pleural effusion:

  • Recurrent aspiration
  • pleurodesis
  • Indwelling pleural catheter
  • Drug management to alleviate symptoms - opioids