Lecture on Pleural Diseases

Introduction

• Focus on two pleural diseases: Pleural Effusions and Pneumothorax.
• Supporting learning resources available through website including notes, illustrations, and courses for exams like Step 1, Step 2, and more.

Pleural Diseases Overview

Pleural Effusions

• Problem: Fluid accumulation in the pleural space (between parietal and visceral pleura).
• Symptoms:
  • Pleuritic chest pain (pain when breathing in and out).
  • Dyspnea (difficulty breathing).
• Physical Exam Findings:
  • Decreased tactile fremitus.
  • Dullness on percussion.
  • Decreased breath sounds.

Types of Pleural Effusions

• Transudative Effusions:
  • Fluid with low protein and cells.
  • Common causes: Congestive heart failure (CHF), cirrhosis, nephrotic syndrome.
  • Mechanism: Increased pulmonary capillary wedge pressure or decreased oncotic pressure.
• Exudative Effusions:
  • Fluid with high protein, LDH, and possibly white blood cells.
  • Causes: Pneumonia (common), tuberculosis, malignancy, autoimmune diseases, trauma.
  • Mechanism: Lung injury or inflammation causing increased capillary leakage.

Pneumothorax

• Problem: Air in the pleural cavity.
• Symptoms: Similar to pleural effusion but with tympany on percussion.

Types of Pneumothorax

• Primary Spontaneous:
  • No underlying lung disease.
  • Common in tall, thin, young males; associated with subpleural apical blebs.
• Secondary Spontaneous:
  • Associated with underlying lung diseases like COPD, asthma, or lung necrosis.
• Trauma:
  • External causes (e.g., needle puncture) and internal causes (e.g., high airway pressures in mechanical ventilation).

Complications of Pleural Diseases

Pleural Effusion Complications

• Atelectasis:
  • Compression of lung tissue leading to collapse and V/Q mismatch.
  • Can cause hypoxemia and respiratory distress.
• Empyema:
  • Progression from uncomplicated to complicated effusion (infected) to frank pus formation.
  • Signs: Persistent fever, high white blood cell count, potential sepsis.

Pneumothorax Complications

• Tension Pneumothorax:
  • One-way valve effect causing air to build and shift mediastinum.
  • Symptoms: Tracheal deviation, hypotension, JVD, absent breath sounds.

Diagnosis

Pleural Effusions

• Chest X-ray: Identifying meniscus sign.
• Chest CT: For complication assessment.
• Thoracentesis: Differentiates transudative vs. exudative using Light's criteria.
  • Exudative if:
    • Pleural fluid protein/serum protein ratio > 0.5.
    • Pleural fluid LDH/serum LDH ratio > 0.6.
    • Pleural LDH > two-thirds upper normal serum LDH.

Pneumothorax

• Chest X-ray/CT: Absence of lung markings, presence of pleural line.
• Differential: Based on history and imaging for underlying lung disease.

Management

Pleural Effusions

• Thoracentesis: For immediate relief.
• Underlying Cause Treatment: Prevent reaccumulation.
• Chest Tube: For empyema or large hemothorax.
• Pleurodesis: For recurrent malignant effusions.

Pneumothorax

• Observation: For small pneumothorax (<2 cm).
• Chest Tube: For large pneumothorax or respiratory distress.
• Needle Decompression: For tension pneumothorax.

Additional Considerations

• Chest Tubes: Monitoring collection, water seal, and suction control chambers.
  • Watch for titling, excessive bubbling indicating air leak or excessive suction.

Conclusion

• Understanding the pathophysiology, diagnosis, and management strategies for pleural diseases is crucial for effective treatment and prevention of complications.