Pleural, Pericardial, and Ascitic Fluids

The pleural, pericardial, and peritoneal cavities normally contain a small amount of serous fluid that lubricates the opposing parietal and visceral membrane surfaces. Inflammation or infections affecting the cavities cause fluid to accumulate. The fluid may be removed to determine if it is an effusion or an exudate, a distinction made possible by protein or enzyme analysis. The collection procedure is called paracentesis. When specifically apphed to the pleural cavity, the procedure is a thoracentesis if applied to the pericardial cavity, a pericardiocentesis. Paracenteses shordd be performed only by sldlled and experienced physicians. Pericardiocentesis has now been largely supplanted by echocardiography. 

The skin over the intended puncture site should be cleaned with 70% isopropanol and then allowed to dry in 

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Many errors can occur during the collection, processing, and transport of biological specimens. Minimizing these errors win result in more reliable information for use by healthcare professionals. Examples of biological specimens that are analyzed in clinical laboratories include whole blood serum plasma urine feces saliva spinal, synovial, amniotic, pleural, pericardial, and ascitic fluids and various types of solid tissue. The National Committee for CMnical Laboratory Standards (NCCLS) has published several procedures for collecting many of these specimens under standardized conditio ns.In addition, the NCCLS has published documents related to sample collection and analysis for specialized tests, such as sweat chloride (see also Chapter 27). 

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