CLS 1521 and CLS 1531
                                            SEROUS FLUID
                            Objectives with narrative and illustrations.

01     DISCUSS SEROUS FLUIDS AND WHERE THEY ARE FOUND.

Serous fluid is found between the serous membranes that lines the organs and closed cavities of the body: the pleural, pericardial, and peritoneal cavities. The serous membranes are thin layers of connective tissue and covered with a single layer of mesothelial cells. A tiny vascular system is found within these membranes. Each organ is encapsulated with a serous membrane (visceral membrane) and its body wall is lined with a similar serous membrane, the parietal membrane. A thin layer of fluid, acting as a lubricant, separates the two membranes and permit free movement. Generally the parietal membrane forms the serous fluid and the visceral membrane absorbs it. If the serous fluid is collected from the membranes around the heart, it is pericardial fluid; if from the abdomen, then it is peritoneal fluid; and if from the chest, then it is pleural fluid.

02     GLOSSARY: DEFINE THE FOLLOWING TERMS ASSOCIATED WITH SEROUS FLUIDS.

Ascites..... excessive accumulation of a pale, straw-colored, clear fluid in the peritoneal
                    cavity.
Anasarca.... severe accumulation of body fluid in the tissues.
Chylous..... having the nature of chyle (products of digestion, consisting of
                     absorbed fats).
Edema....... generalized condition in which the tissues contain an excess of
                      body fluid.
Effusion.... fluid that escapes and collects in a body cavity, usually associated
                    with a pathological process.
Exudate..... fluid produced by the membranes of a cavity that are affected
                      by some pathology (inflammation, infection or malignancy).
Fibrinous.... any fluid that contains fibrinogen and will likely clot on standing.
Milky......... a term that describes any chylous or pseudochylous specimen.
Paracentesis.... a surgical technique in which a puncture of a cavity is
                              performed and fluid is removed.
Pseudochylous.... an effusion that appears milky but does not contain
                                 absorbed fats (chylomicrons).
Purulent...... a fluid characterized by being thick, white, and turbid. It contains
                       numerous WBC and bacteria.
Sanguineous.... the presence of blood in a fluid.
Serous fluid.... having the nature of serum, in this case an ultrafiltrate of plasma.
Shimmering.... any fluid specimen having a greenish to golden iridescent
                            appearance. This fluid usually contains cholesterol and/or
                            cholesterol crystals.
Transudate.... fluid formed as a result of hydrostatic changes that alters the
                           normal rate of fluid filtration and absorption.

03    LIST THE SEROUS FLUID VOLUME REQUIREMENTS FOR LABORATORY TESTING.

Color........ 1 to 3 mLs. May be recorded by the physician at the bedside.
Clarity...... 1 to 3 mLs. May be recorded by the physician at the bedside.
Cell count (diff)... Ideally about 8.0 mLs, but with a minimum of about 4 to 5 mLs collected in sodium heparin or EDTA.
Cytology..... The more the better. A minimum of 25 mLs in sodium heparin.
Gram stain... More is better since it increases the chances of recovering microorganisms. 20 to 25 mLs should be the minimum. The same rule applies for acid-fast stains.
Glucose...... 5 mLs preferred, 10 mLs better. Minimum = 3.0 mLs. If an anticoagulant is used, it is recommended that it contain NaF.
Protein...... Ideally collect 10 mLs in a plain tube. Minimum volume recommended is 5 mLs. This is also applicable for lactate dehydrogenase (LD), amylase, cholesterol, triglycerides, and a number of other tests.
pH..... 1 to 3 mLs recommended, but 5 mLs is better.

04     DISCUSS TRANSUDATES.

This is an effusion that forms in any of the body cavities as a result of increases in hydrostatic pressure or a decrease in oncotic pressure. A non-inflammatory systemic disease is the usual cause for the formation of transudates. Such disorders include: congestive heart failure, hepatic cirrhosis, nephrotic syndrome.

05    DISCUSS EXUDATES.

This is an effusion that forms in any of the body cavities as a result of an inflammatory process (infections or malignancies) that affects the capillaries by increasing their permeability or decreasing the absorption of fluid by the lymphatic system. Exudates require more laboratory testing: microbiological studies to identify an infective microorganism or cell study to determine the type of malignancy.

06     DIFFERENTIATE BETWEEN EXUDATES AND TRANSUDATES USING A MINIMUM OF EIGHT PARAMETERS.

                                                              EXUDATE                TRANSUDATE
Appearance.......                                      cloudy                             clear
Cell Count (WBC)..                                >1000/μL                   <1000/μL
Differential count......                           ↑ Neutrophils           ↑ Mononuclear cells
Total Protein.....                                   >3000 mg/dL            <3000 mg/dL
Serous fluid/serum protein ratio..            >0.5                             <0.5
Lactic Acid Dehydrogenase (LD)...       >200 IU/L                  <200 IU/L
Serous fluid/serum LD ratio.....                  >0.6                             <0.6
Specific gravity...............                             >1.015                         <1.015
Clotting (spontaneous)........                           NO                            Possible
Glucose.....................                             ≤serum level               equal serum level

07     DISCUSS THE VALUE OF A DIFFERENTIAL CELL COUNT IN SEROUS FLUID.

This evaluation procedure can provide some diagnostic information.
1.     There are a number of different cell types found in serous fluids
        (pericardial, peritoneum, and pleural). Neutrophils, eosinophils,
         lymphocytes, monocytes, macrophages, plasma cells, mesothelial cells,
         and malignant cells have been found in a variety of conditions.
2.    If the condition is tubercular, then lymphocytes seem to dominate, but if
       the problem is a bacterial infection, then neutrophils are predominate.
3.     Mesothelial cells may represent a problem in identification. These cells
         sloughed off and are commonly observed in effusions. They are large
         cells with diameters of up to 30 μM. The normal cell tends to have    
         abundant cytoplasm, can be multinucleated, and may resemble plasma
         cells. Degenerative cells may resemble malignant cells.  Refer to the
         following illustrations..
   
        Normal Mesothelial Cells                    Reactive, Multinucleate
                                                                              Mesothelial Cells
        Note:  Neutrophils are included for approximate size comparison.

4.     If a malignancy, look for cell clumps and cells with an irregular nuclear
         membrane and uneven distribution of nuclear material.  Multiple
         nucleoli are frequently seen and these will have membrane irregularities.
        Neoplastic cells have a higher nuclear
         to cytoplasm ratio.  These cells can be large.  Such cells should be verified
         and identified by a pathologist.
         NOTE... in malignancies, lymphocytes tend to predominate. Refer to the
         following illustration.  Also you may refer to Figure 3  in the spinal fluid syllabus.
                 
                                                        Malignant Cells
                 NOTE:  A neutrophil is included for approximate size comparison.

This web site is maintained by Whitney Williams, wwilliam@astate.edu

This page last updated 07/28/08