[Examination of the pleural effusion and its interpretation]

Pleural effusion appears in the course of respiratory diseases and disorders of other organs. Examination of the effusion enables differentiation between exudate or transudate. It allows to estimate the severity of the disease, helps to choose the way of treatment and assesses its effects. In most cases Light's criteria are sufficient for differentiation between exudate and transudate. If the patient has an exudative pleural effusion additional tests are indicated to determine the etiology of the effusion. Laboratory tests which are useful in the further diagnostics of pleural effusion include: bacterial cultures, cytological and biochemical tests.