Cardiothoracic Surgery: Lung Abscess

Basics

• Definition: A Circumscribed Purulent Infection of the Lung Parenchyma
• Types:
  • Primary: From Direct Infection of the Pulmonary Parenchyma (Aspiration, Direct Extension, etc.)
  • Secondary: From Predisposing Conditions (Bronchial Obstruction, Septic Embolization, etc.)
• Most Common Site: Superior Right Lower Lobe (Most Common Site of Aspiration)

Causes

• Aspiration – Most Common Cause
• Secondary Infection of Pre-Existing Lung Cavities
• Bronchial Obstruction (Foreign Body or Neoplasm)
• Septic Embolization (Hematogenous Spread from Right-Sided Endocarditis)
• Direct Extension from Empyema

Organisms

• Most are Polymicrobial
• Staphylococcus aureus – Most Common Single Pyogenic Organism
• Klebsiella pneumonia
• Pseudomonas aeruginosa

Presentation

• Usually Chronic with Slow Evolution Over Weeks-Months
• Fever
• Productive Cough
• Dyspnea
• Pleuritic Chest Pain
• Hemoptysis
• Weight Loss
• Fatigue

Diagnosis

• Primary Diagnostic Evaluation:
  • CT Chest
  • Sputum & Blood Cultures – Before Starting Antibiotics
• Consider Bronchoscopy if Presentation Atypical or Diagnosis Uncertain to Evaluate for Cancer
  • Routine Use Unnecessary

Treatment

• Primary Treatment: Empiric Antibiotics
  • Generally Requires a Prolonged Course (2-4 Weeks)
• Percutaneous (Transthoracic) Drainage
  • Indications:
    • Antibiotic Failure (After 7-10 Days)
    • Size > 6 cm
  • Transbronchoscopic Drainage is Considered an Alternative for Central Lesions Away from the Chest Wall
• Surgery
  • Required in 10% of Cases
  • Indications:
    • Antibiotic Failure with/without Percutaneous Drainage
    • Size > 6 cm
    • Significant Hemorrhage
    • Bronchopleural Fistula
    • Rupture of Abscess into Pleural Cavity with Pyopneumothorax/Empyema
  • Surgical Procedures:
    • Lobectomy – Most Common
    • Segmentectomy
    • Pneumonectomy