Pleural Effusion - fluid in the pleural space
Can be divided in to transudates and exudates, depending on protein concentration in the fluid. Draw of a diagnostic tap (10-30ml)
Exudates - protein >35g/L
Infection - pneumonia, TB
Inflammation - PE, pancreatitis, rheumatoid, lupus
Malignancy - lung, mets, mesothelioma, lymphoma
To help remember the difference I like to think of an exudate as an exuding wound with lots of INFLAMMATION
Transudates - protein <25g/L
increased venous pressure - cardiac failure, fluid overload
low protein - cirrhosis, nephrotic syndrome, malabsorption
Others e.g. hypothyroidism, Meigs' syndrome
If between 25-35g/L then apply Light's Criteria, this compares the protein level to serum levels











