Empyema/Parapneumonic Effusion

Empyema/Parapneumonic Effusion


  • Exudative effusion
  • pH >7.2
  • Gram stain & culture negative

Generally resolves with treatment of pneumonia and does not require modification of pneumonia therapy

  • Loculated
  • pH > 7.2
  • NOT frankly purulent
  • Gram stain & culture may/may not be positive

Requires drainage

  • Frank pus
  • Gram stain or culture often positive, but may be culture negative

Requires drainage

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


Uncomplicated Parapneumonic Effusion

  • Same organisms as CAP or HAP

Additional Information

Guideline originally sourced from Island Health and adapted by Joseph Brant Hospital

  • Shen KR, et al. The American Association for Thoracic Surgery consensus guidelines for the management of empyema. J Thorac Cardiovasc Surg 2017;153:e129–e146.

  • Colice GL, Curtis A, Deslauriers J, et al. Medical and surgical treatment of parapneumonic effusions: an evidence-based guideline. Chest 2000;118:1158-71.

  • Sinai Health System & UHN Antimicrobial Stewardship Programs. Empyema Treatment Guideline. (No Date) Accessed April 2020 from:

  • The Johns Hopkins University (2020) John Hopkins ABX Guide (1.27) [Mobile App] Retrieved from:

  • Antimicrobial Therapy Inc (2020) The Sanford Guide (4.2) [Mobile App] Retrieved from:

Approved: April 2020