What’s that in your pleural space?

Parapneumonic Effusions

Parapneumonic effusions are effusions that occur in the pleural space adjacent to bacterial pneumonia.
  • Uncomplicated: exudative, normal pH/glucose and negative gram stain/culture
  • Complicated: exudative, low pH (<7.20), a low glucose and and often loculated
  • Empyema: pus and organism visible on gram stain, although cultures maybe negative
Indications for Thoracentesis
  • free flowing, layers > 25mm on a lateral decubitus film or CT
  • loculated
  • associated with thickened parietal pleura on CT scan, a finding suggestive of empyema
  • clearly delineated by US
Pleural Fluid Studies
  • See here for our previous review of pleural fluid studies
Management
  • Large loculated or complicated parapneumonic effusion: chest tube
  • Empyema: chest tube and VATS with debridement +/- decortication
Microbiology
  • Same bugs that cause pneumonia: strep pneumo most common. Others include Strep milleri, Staph aureus and Enterobacteriaceae
  • Anaerobic bacteria have been cultured in 36 to 76% of empyema; Fusobacterium, Prevotella, Peptosteptococcus , Bacteroides.
Antibiotics
  • Always cover for anaerobes (hard to culture so treat empirically)