TABLE 25-2.

Light criteria with individual sensitivity and specificity of tests to distinguish exudative from transudative effusions

Pleural fluid may be classified as exudative, if one or more of the following criteria are met:

■ Pleural fluid protein divided by serum protein >0.5 (Sensitivity 98%, Specificity 83%)

■ Pleural fluid lactate dehydrogenase (LDH) divided by serum LDH  >  0.6 (Sensitivity 86%, Specificity 84%)

■ Pleural fluid LDH is more than two-thirds of the upper limit of normal for serum LDH (Sensitivity 82%, Specificity 89%)

Adapted from Light (2002)