Empyema diagnostic criteria

Thoracentesis fluid with a positive Gram stain or culture,

pleural fluid glucose <40 milligrams/dL, 

pH <7.1, 

or lactate dehydrogenase >1000 IU/L. 

 Empyema has three stages that impact treatment:

1. Exudative 

(may be very short, <48 hours, the free-flowing pleural effusion that is present is amenable to chest tube drainage)

2. Fibrinopurulent 

(fibrin strands form in the pleural fluid causing loculations, resolution of the empyema with single chest tube drainage is unlikely)

3. Organizational 

(takes several weeks, more extensive fibrosis, “pleural peel restricts lung expansion)