Straw coloured
Cardiac failure
Hypoalbuminaemia
Bloody
Trauma
Malignancy
Infection
Infarction
Turbid/milky
Empyema
Chylothorax
Foul smelling
Anaerobic emyema
Food particles
Oesophageal rupture
Pleural pH <7.2
Requires drainage in the setting of infection!
Low glucose
Rheumatoid arthritis
Tuberculosis
Raised amylase
Pancreatitis
Oesophageal rupture
Heavy blood stained
Mesothelioma
Pulmonary embolism
Tuberculosis