Empyema classification

Empyema Microchapters
Patient Information
Overview
Classification Subdural empyema Pleural empyema
Differential Diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Classification

Empyema may be classified according to the etiology, anatomical location, and pathological course of the disease as follows:

Primary vs secondary empyema

Primary empyema occurs most commonly as iatrogenic empyema without associated pneumonia whereas secondary empyema happens more commonly secondary to pneumonia.

Empyema necessitans

Empyema necessitans is a spontaneous discharge of an empyema that has burrowed through the parietal pleura into the chest wall to form a subcutaneous abscess that may eventually rupture through the skin.

Stages of empyema

Empyema may be classified according to the stage of the disease as follows:

• Exudative

In the exudative stage, the pus accumulates, and initial sterile fluid becomes infected with fluid characteristics of;

• • glucose>60
  • pH>7.2
  • LDH<500

• Fibrinopurulent

During this stage, bacterial multiplies with increase in polymorphs and fibrin deposition on both pleural surfaces with fluid characteristics of;

• • glucose<40
  • pH <7.2
  • LDH>1000

• Organizing

This stage is characterized by loculations, inelastic membranous peel, and lung entrapment as a result of scarring of the pleural space.