الفهرس 
Anatomy of the PleuraOnly 14 pages are availabe for public view
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Abstract
Although the pleural cavity contains a small amount of pleural fluid in normal conditions the amount of fluid increases up to a few liters (an effusion) during pathological changes.
The differentiation of pleural effusion as being a transudate or exudate is first step in the diagnosis of pleural effusion. Defining an effusion as transudate limits the differential diagnosis and the need for further diagnostic procedures, since a transudate is due to systemic factors, such as congestive heart failure, in contrast, exudate always requires extensive and invasive procedures.
The criteria established by Light et al., (1972) is the standard method for this discrimination.
However, in some prospective studies applying the criteria of Light et al., the sensitivity for exudates remained high but the specificity did not. For this reason several recent studies have evaluated alternative criteria, such as, serum- pleural fluid albumin gradient, pleural fluid to serum cholesterol and bilirubin ratios, etc.,
In some of these studies authors have claimed that the parameters tested as alternative criteria showed higher sensitivity and specificity for differentiation of transudates and exudates. In others, however, the criteria of Light et al., had higher sensitivity and specificity than the alternative criteria.
The aim of this study was to compare the efficiency of pleural fluid level of new parameters (CK, uric acid and bilirubin) as well as pleural fluid to serum ratios of these new parameters to the traditional light’s criteria for differentiating exudates from transudates.
The present study included thirty patients of pleural effusion due to different etiologies those were admitted at the Chest, Cardiac and Tropical Departments of Ain Shams University Hospitals in the period between November 2007 till April 2008.
Patients were classified into 2 groups on basis of their diagnosis:
Group (I): Fifteen patients with exudative pleural effusion.
Group (II): Fifteen patients with transudative pleural effusion.
All patients included in the present study were subjected to the following:
• Full medical history taking.
• Thorough clinical examination.
• Chest X-ray (postero anterior and lateral views).
• Routine laboratory investigations (complete blood count, liver and kidney profiles, plasma glucose and electrolytes profiles).
• Thoracocentesis and examination of pleural fluid as regard:
Gross appearance and nature of fluid.
Cytological examination for type of cells in the fluid.
Bacteriological examination including gram stain, leishman stain and Ziehl-Neelsen stain.
Biochemical analysis of pleural fluid for
- Total protein content.
- Lactate dehydrogenase enzyme.
- Uric acid level.
- Creatine kinase level.
- Total bilirubin level.
• Serum sample obtained simultaneously to measure.
- Total protein content.
- Lactate dehydogenase enzyme.
- Uric acid level.
- Creatine kinase level.
- Total bilirubin level.
• Other investigations sometimes needed for proper diagnosis of pleural effusion e.g., C.T. chest, tuberculin test and pleural biopsy.
The result of the present study showed that the tested new parameters (CK, uric acid and bilirubin) are useful markers for distinguation between pleural exudates and transudates.
Also pleural fluid and pleural fluid/serum ratios of the tested new parameters were higher in exudates in comparison to transudates except uric acid which was in opposite to all parameters higher in pleural fluid and serum of transudates, furthermore pleural fluid/serum ratio of uric acid was non significant for purpose of distinction between exudates and transudates
The results of the present study also revealed that the tested new parameters in comparison with traditional lights criteria had nearly the same sensitivity and specificity but they were more accurate than light’s criteria, so, new parameters considered more efficient than traditional light’s criteria for purpose of discrimination of pleural exudates and transudates.