Pleural Effusion

Snapshot

• A 55-year-old male with congestive heart failure, coronary artery disease, and hypertension presents to your urgent care with shortness of breath. He is on vacation and lost his medications during his travel. He reports that his shortness of breath has been getting worse over the past few days, especially when he is walking. His exam is notable for decreased lung sounds bilaterally with overlying dullness to percussion and bilateral 1+ pitting edema to the knees. A chest radiograph was performed, which showed blunting of the costophrenic angles.

Introduction

• Clinical definition
  • pathologic accumulation of fluid in the pleural space (5 – 10 cc physiologically)
• Epidemiology
  • incidence
    • the most common cause in the United States
      • congestive heart failure, pneumonia, and malignancy
    • the most common cause in the world
      • tuberculosis
• Etiology
  • any abnormal balance between fluid entering and/or exiting pleural space
• Pathogenesis
  • characteristics of the fluid suggest the pathogenesis
    • transudative
      • ↑ hydrostatic pressure or ↓ capillary oncotic pressure
    • exudative
      • ↑ capillary permeability
• Prognosis
• depends on etiology and baseline pulmonary function

Presentation

• Symptoms
  • asymptomatic
  • dyspnea and/or dyspnea on exertion
  • cough
• Physical examination
  • ↓ breath sounds
  • ↓ tactile fremitus
    • versus consolidation, which ↑ breath sounds
• Special presentation
  • hepatic hydrothorax
• intra-abdominal fluid enters via diaphragmatic defects

Imaging

• Chest radiography 
  • upright show blunting of the costophrenic angles 
• lateral decubitus shows layering if free flowing 

Studies

• Thoracentesis 
  • diagnostic gold standard
  • indicated for new effusions
• Fluid studies 
  • Gram stain and culture
  • cell count with differential
  • cytology
  • Light criteria   

Light Criteria for Pleural Fluid Analysis
	Transudative	Exudative
Fluid LDH	≤ 2/3 upper limit of normal serum	> 2/3 upper limit of normal serum
Fluid LDH/Serum LDH	≤ 0.6	> 0.6
Fluid total protein/serum total protein	≤ 0.5	> 0.5
Diagnosis	Must meet all criteria to diagnose a transudate	Meet any single criterion to diagnose exudate

Differential Diagnosis

• Pyothorax
• Hemothorax
• Chylothorax

Treatment

• Management approach
  • if high suspicion of congestive heart failure, diurese
  • if new effusion, perform diagnostic and therapeutic thoracentesis
  • concurrent treatment of the underlying disease 
• Interventional 
  • therapeutic thoracentesis
  • thoracostomy or thoracotomy
    • indication
      • loculated effusions
  • pleurodesis and decortication
    • indication
• indwelling catheter for recurrent effusion 

Complications

• Empyema
• Loculation
• Pneumothorax from thoracentesis