title: Pleural effusions. 2. Definitive evaluation of the exudate.
abstract: Based on the current literature, the following steps seem reasonable in evaluating a pleural effusion: document the presence, location, and approximate volume of pleural fluid; decide clinically on the likelihood of an exudative effusion; if clinical evaluation suggests an exudative effusion, perform a thoracentesis and obtain fluid for diagnostic evaluation; perform the necessary tests to characterize the effusion as a transudate or an exudate; if a transudate exists, normally do not perform further tests on the effusion; if an exudate exists, perform selected tests to narrow the differential diagnosis; if this evaluation is undiagnostic, consider closed pleural biopsy; if the diagnosis remains unclear after two closed biopsies, consider pleuroscopy with biopsy or open pleural biopsy at the time of a thoracotomy.
mesh_terms: D000681:Amylases / Q000032:analysis; D001706:Biopsy; D002452:Cell Count; D005122:Exudates and Transudates / Q000032:analysis / Q000166:cytology; D005947:Glucose / Q000032:analysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000032:analysis; D010996:Pleural Effusion / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D013906:Thoracoscopy
chemical_list: D008055:Lipids; D000681:Amylases; D005947:Glucose