THE DIAGNOSTIC-VALUE OF PLEURAL FLUID ANALYSIS

A thorough knowledge of the common hematologic and biochemical tests of pleural fluid in conjunction with the clinical presentation should allow the clinician to determine the cause of the patient's pleural effusion following the initial pleural fluid analysis. At times, however, the patient's clinical presentation and stage of disease does not allow a definitive diagnosis. Close observation of the patient and repeat pleural fluid analysis usually will be diagnostic. Thoracoscopy will establish the diagnosis of a malignant pleural effusion in virtually all cases, while pleural biopsy remains the single best diagnostic test to establish the diagnosis of tuberculous pleurisy. Thoracoscopy is of minimal value in the diagnosis of the nonmalignant pleural effusion and is unnecessary in the diagnosis of tuberculous effusions.