Transudative: increased Pcapillary pressure in the viseral or parenteral pleura (CHF) or decreased plasma oncotic pressure (hypoalbuminemia 2/2 nephrotic syndrome for example) which will pull nothing into vessel. Ex include CHF, cirrhosis, PE, nephrotic syndrome, peritoneal dialysis, hypoalbuminemia, atelectasis (collapsed lung)
Exudative: increased permeability of pleural surface or decrased lymphatic flow from pleural surface 2/2 damaged pleural membranes/vasculature. Examples includ bacterial pneumonia, malignancy, TB, PE, viral infection, PE, CVD.
USE LIGHTS CRITERIA to dx that of exudative:
-must have one of any three to be diagnosed with a transudative versus an exudative:
1. Pleural LDH/Serum LDH > 0.6
2. Pleural protein/Serum protein > 0.5
3. Pleural LDH > 2/3 upper limit of serum LDH