Southern medical journal
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Southern medical journal · Dec 1989
Comparative StudyPleural effusion: comparison of clinical judgment and Light's criteria in determining the cause.
Pleural fluid analysis is often the initial diagnostic test used to determine the cause of a pleural effusion. We prospectively studied 33 consecutive patients with pleural effusions to determine whether the fluid arose from a transudative or an exudative process. Clinical judgment by an internist before thoracentesis and both serum and pleural fluid protein and lactic dehydrogenase levels (commonly referred to as "Light's criteria") were compared to the patient's final diagnosis. ⋯ Clinical judgment and Light's criteria are comparable in their ability to predict whether an exudative or transudative process was responsible for the effusion. Both methods are associated with errors, though of different kinds; these errors occurred infrequently. Recognizing the limitations of these methods will permit the most accurate effusion categorization.