Pleural Effusion

Relevant physical signs

• Characteristics of pleural effusion
  • Presence of respiratory distress
  • Tracheal deviation (usually central unless pleural effusion is massive)
    • If due to massive pleural effusion, will be deviated away from side of the lesion
    • May be deviated towards the side of the effusion if there is collapse secondary to mitotic lesion with carcinomatous pleural effusion
  • Scars
    • Previous thoracocentesis
    • Previous chest drain placement
    • VATS scars for previous lung / pleural biopsy
  • Unilateral / bilateral pleural effusion
  • Decreased chest expansion on the side of the pleural effusion
  • Stony dull percussion note till the level of the effusion
  • Decreased air entry on the side of the lesion
  • Reduced vocal resonance on the side of the lesion
• Underlying malignancy (usually unilateral)
  • Cachexia
  • Clubbing
  • Tar staining of the fingers
  • Non-scarring alopecia
  • Mastectomy scar
  • Cervical lymphadenopathy
  • Collapse of a lung lobe
• Fluid overload states (usually bilateral)
  • Raised jugular venous pulsation
  • Displaced apex beat
  • Right ventricular heave
  • Coarse crepitations of pulmonary oedema
  • Peripheral oedema
• Underlying inflammatory connective tissue disorder (may be bilateral or unilateral)
  • Symmetrical deforming polyarthropathy
  • Rheumatoid nodules
  • Malar rash / vasculitic rash
  • Livedo reticularis

Differential diagnosis of dullness to percussion with reduced breath sounds

• Pleural effusion
• Consolidation (would expect dull percussion, reduced chest expansion but bronchial breathing rather than reduced breath sounds)
• Pleural thickening (breath sounds more audible)
• Collapse (trachea should be deviated towards the side of the dullness)
• Fibrosis (associated with fine, end-inspiratory crepitations)
• Raised hemidiaphragm secondary to phrenic nerve palsy or hepatosplenomegaly

Differential diagnosis of a pleural effusion

• Exudative
  • Infection
    • Tuberculosis
    • Para-pneumonic
    • Pleural empyema
    • Bronchiectasis
    • Yellow nail syndrome
  • Neoplastic
    • Lung carcinoma
    • Primary pleural malignancy
    • Secondary metastatic spread, e.g. from breast carcinoma
    • Meig’s syndrome from ovarian fibroma
  • Inflammatory
    • Systemic lupus erythematosus
    • Rheumatoid arthritis
    • Sarcoidosis
    • Systemic sclerosis
    • Dressler’s syndrome
  • Drugs
    • Bromocriptine
    • Nitrofurantoin
    • Methotrexate
  • Pulmonary embolism with infarction
  • Trauma
  • Asbestosis
• Transudative
  • Congestive cardiac failure
  • Nephrotic syndrome
  • Chronic liver disease
  • Hypothyroidism
  • Meigs’ syndrome (ovarian fibromas with transudative, usually right-sided, pleural effusion)
• Chylothorax
  • Lymphoma
  • Chronic lymphocytic leukaemia
  • Post-surgical
    • Oesophagectomy
    • Lung resection with lymph node dissection
  • Complication of central venous catheter insertion
• Haemothorax secondary to trauma

Investigations

• Chest radiograph
  • Posterior-anterior film looking for obliteration of the costophrenic angles, meniscus of effusion
  • Consider lateral decubitus film in small effusions
• Ultrasound-guided diagnostic thoracocentesis
  • Classify effusion into an exudate or transudate by Light’s criteria (at least one of the following)
    • Pleural fluid protein to serum protein ration of > 0.5 (or protein > 30g/dL)
    • Pleural fluid LDH to serum LDH ratio > 0.6
    • Pleural fluid LDH > two thirds the upper limit of normal of serum value
  • pH (usually 7.60 – 7.64), < 7.2 indicates need for drainage of parapneumonic effusion
  • Adenosine deaminase (values over 50-60 have positive predictive value for TB)
  • Cell count to look for granulocytosis or lymphocytosis
  • Gram stain and fluid culture
  • Acid-fast bacilli smear and culture
  • Cytology to look for malignant cells
  • Glucose (low in infections)
  • Consider
    • Cholesterol to rule out chylothorax if effusion is milky (>4g/L)
    • Amylase (acute pancreatitis)
    • Haematocrit (haemothorax if ratio of pleural to serum haematocrit is > 0.5)
  • Blood tests (at the time of thoracocentesis)
    • Full blood count
    • Serum glucose
    • Serum protein
    • Serum LDH
• Computed tomography of the chest to look for underlying malignancy if cytology positive
• Consider pleural biopsy to look for MTB if clinical index of suspicion is high

Management

• Multidisciplinary team approach
• Basic resuscitative measures, if necessary
  • Oxygen supplementation
  • Hydration and haemodynamic support
  • Chest physiotherapy
• Therapeutic chest drainage
  • Slow drainage to avoid re-expansion pulmonary oedema
  • Indications
    • Complicated para-pneumonic effusions
    • Pleural empyema (positive Gram stain / frank pus on aspiration / positive culture)
    • Malignant pleural effusion, if symptomatic
    • Chylothorax
    • Haemothorax
  • Complications
    • Pneumothorax
    • Haemothorax
    • Re-expansion pulmonary oedema
    • Hypotension
• Consider surgical decortication for empyema
• Recurrent pleural effusions
  • Talc pleurodesis
  • Placement of indwelling pleural drainage catheter
  • Surgical (VATS) pleurodesis

Summary

Sir, this patient has a pleural effusion. On examination of the chest, there is reduced chest expansion on the right side. The percussion note is stony dull, and there is reduced air entry and vocal resonance for one half of the posterior hemithorax. The patient is not in respiratory distress, and the trachea is central. With regards to underlying aetiology, there is no palpable lymphadenopathy, clubbing or tar staining of the fingers to suggest a mitotic process. I would like to measure the patient’s temperature to look for evidence of infection, although there are no crepitations to suggest this. There is no arthropathy or rash which would suggest underlying autoimmune disease. Possible differential diagnoses for dullness with reduced air entry include pleural thickening, asbestos-related pleural disease, primary mitotic processes of the pleura, lung collapse – although I would expect tracheal deviation towards the affected side, consolidation and previous lobectomy / pneumonectomy – although there are no scars to suggest this.

In summary, this patient has a unilateral pleural effusion which is currently not causing respiratory symptoms.