Stage I (exudative stage)

Uncomplicated parapneumonic effusion

Stage II (fibrinopurulent stage)

Complicated parapneumonic effusion

Stage III

Rapid free-flow of fluid caused by the movement of increased pulmonary interstitial fluid from the pleura into the pleura space. Pleura surfaces are inflamed and permeable

Bacterial infection and fibrin deposition. Fluid color goes from clear yellow to frank pus.

If stage II isn’t drained, the effusion organizes and evolves into stage III

Fibroblastic ingrowth and collagen deposition.

After 3-4 weeks a thickened membrane, “peel” develops that creates a trapped lung and ultimately restricts pulmonary function.

Persistence of empyema cavity after 7-10 days of chest tube and failure of lung expansion

Pleura fluid cultures are negative, pH> 7.2, LDH<1000 mg/100ml

Cultures are positive, pH<7 glucose<40

Management requires antibiotics and drainage only if symptomatic

Intrapleural fibrinolytic therapy with tPA and DNase can be used.

Antibiotics plus chest tube drainage.

VATS or open drainage, debridement and decortication.