Mediastinitis

Background

• Infection of the structures in the mediastinum

CDC Definition

• One of the following:
  • Organisms cultured from mediastinal tissue or fluid
  • Gross anatomical or histopathologic evidence of mediastinitis
  • Fever, chest pain, or sternal instability
• Plus one of the following:
  • Purulence from the mediastinal area
  • Mediastinal widening on imaging

Microbiology

• Post-cardiac surgery: coagulase-negative staphylococci, Staphylococcus aureus
• Esophageal rupture: polymicrobial, with oropharyngeal and gastrointestinal flora including anaerobes
• Can also occur from contiguous extension of pneumonia, pancreatitis, subphrenic abscess, or epidural abscess, with the microbiology determined by the source of infection

Clinical Manfestation

• Usually presents within 30 days of surgery
• Fever, chest pain, drainage from surgical site
• See CDC definition, above

Investigations

• CT chest can show evidence, including sternal wire displacement, sternal disruption, free gas, or fluid collections
• Surgical exploration, with fluid sent for culture

Management

• Surgical exploration with debridement
• Antimicrobials directed by culture results