Spectrum: Local Antimicrobial Stewardship, for Eastern Health

Empyema Dx

Management - drainage

Imaging

Chest xray

Can reveal loculated fluid (i.e. does not layer out on lat decubitus) suggesting either empyema or complicated effusions

Ultrasound

Can help to characterize location, and consistency of the fluid (i.e. echogenic fluid more likely empyema)

CT with contrast

Can characterize the fluid location, loculation, and demonstrate thickened/enhancing pleura consistent with empyema or complicated effusions.

Diagnosis

Obtain a CXR with lateral decubitus view

All parapneumonic effusions >10mm depth (by U/S or lateral decubitus film) should be sampled (smaller effusions generally resolve without intervention)

Send pleural fluid for:
  • Gram stain and aerobic/anaerobic culture.

NB innoculate fluid directly into blood culture bottles.

± TB/fungal depending on risk factors.

  • Cell count and differential

  • Chemistry - pH (should be done with blood gas analyzer), total protein, LDH, glucose

Definitions

Uncomplicated parapneumonic effusion

Exudative effusion, pH >7.2, culture and gram stain negative.

Generally resolves with treatment of pneumonia.

Light’s criteria for exudative effusions

One of:

  • Pleural protein to serum protein ratio > 0.5

  • Pleural LDH to serum ratio >0.6

  • Pleural LDH > 0.6 x the upper limit of normal for serum LDH.

Complicated parapneumonic effusion

Any parapneumonic effusion that is loculated, or culture positive, or pH < 7.2, but is not frankly purulent or gram stain positive.

Empyema

Frank pus or organisms on gram stain in pleural fluid.

May be culture negative