Pleural effusion in critically ill patients and intensive care setting

Table 2 Criteria for differentiation between exudative and transudative pleural effusion

Light’s criteria	Pleural fluid only dependent criteria
Pleural fluid is considered exudate if Pleural fluid/serum protein > 0.5, pleural fluid/serum LDH > 0.6, or pleural fluid LDH > two-thirds of upper limits of the laboratory’s normal serum LDH	Pleural fluid is considered exudate if Pleural fluid protein ≥ 3 gm/dL, or pleural fluid cholesterol > 45 mg/dL, or pleural fluid LDH > 0.45 times the upper limit of the laboratory’s normal serum LDH

LDH: Lactate dehydrogenase.