Lecture 9 (Serous Body Fluids) PDF

BODY FLUIDS Dr. RANIA SULIMAN Associate Professor of Medical Laboratory 1.Sciences.Consultant in Histopathology and Cytology  SEROUS FLUIDS  The body cavities (pleural, pericardial, and peritoneal cavities) are lined by two membranes referred to as the serous...

BODY FLUIDS Dr. RANIA SULIMAN Associate Professor of Medical Laboratory 1.Sciences.Consultant in Histopathology and Cytology  SEROUS FLUIDS  The body cavities (pleural, pericardial, and peritoneal cavities) are lined by two membranes referred to as the serous membranes (visceral and parietal) that Lined with mesothelial cells.  The parietal membrane:  Is the membrane lines the wall of the body cavity wall.  The visceral membrane:  Is the membrane that covers the organs within the cavities.  The fluid between the membranes is called serous 2 fluid. 3  SEROUS FLUIDS  Body cavities:  Pericardial (heart)  Pleural (lungs)  Peritoneal (abdominal)  Serous fluids fill the space between visceral and parietal memranes.  Functions:  Acts as lubricant  Provide nutrients 4  Remove wastes  SEROUS FLUIDS  It is “ultra filtrate” of the plasma.  Closely resembles the plasma 5  SEROUS FLUIDS  Produced normally by hydrostatic and oncotic (protein) pressure in the capillaries lining the membranes  The greater hydrostatic pressure in the systemic capillaries on the parietal side favors fluid production through the parietal membrane and reabsorption through the visceral membrane. 6  Normally produced at a constant rate.  SEROUS FLUIDS  Production and re-absorption are influenced by:  Changes in osmotic and hydrostatic pressure in the blood  Concentration of chemical constituents in the plasma  Permeability of blood vessels and the membranes 7  SEROUS FLUIDS  Types of serous fluids:  Pericardial fluid –around heart  Pleural fluid (thoracic fluid) –lung cavity  Peritoneal (ascitic fluid) –abdominal cavity  Reasons for analysis:  Infections  Hemorrhages  malignancies, 8  and other disorders.  SPECIMEN COLLECTION AND HANDLING  Needle aspiration procedures are referred to:  Thoracentesis (pleural)  Pericardiocentesis (pericardial)  Paracentesis (peritoneal)  Abundant fluid (greater than 100 mL) is usually collected  Sometimes peritoneal lavage will be done  Ringer‟s lactate / saline is infused into abdomen then 9 retrieved for analysis. (Also called ascites fluid). SEROUS FLUIDS - EFFUSION  It is an increase in the serous fluid due to some disruption in the mechanisms of production & re-absorption of serous fluid.  Classification of cause of an effusion is aided by determining if the fluid is a “transudate” or an “exudate”. 10  EFFUSION  Transudate:  It is an effusion that is a result of a systemic disorder that disrupts the balance of fluid production / fluid re- absorption.  Examples:  Pleural transudate: caused by an increase in hydrostatic pressure (created by congestive heart failure).  Pericardial transudate: caused by a decreased oncotic pressure (hypoproteinemia created by nephroticsyndrome) or lymphatic obstruction 11 (tumors i.e. metastatic cancer)  EFFUSION  Exudates:  Occur as a result of a problem with the membranes themselves.  Produced by conditions that directly involve the membranes of the particular cavity, i.e. infections, inflammation, and malignancies  Exudate examples:  Pleural exudate: carcinoma, pneumonia, trauma 12  Pericardial exudate: infection, cardiovascular disease (CV) trauma, cancer 13 14  SPECIMEN COLLECTION AND HANDLING - CONTI  EDTA tube for cell count & differential  Heparin tube for chemistries, serology, microbiology and cytology.  Since procedure not performed unless an effusion exists, large amount of fluid often collected.  Blood specimens usually collected at same time 15 and comparisons of test results made.  SEROUS FLUIDS -TESTING  Appearance  Cell counts  Protein level  Both fluid and current serum level to make comparison  LDH enzymes  Both fluid and current serum level to make comparison  Cultures (aerobic & anaerobic) & Gram stain & acid fast  Serology  Rarely done on serous fluids as blood testing is adequate 16  Cytology / Pathology –if malignancy is suspected.  HEMATOLOGY / GROSS EXAMINATION  Color & clarity:  Normal = yellow & clear (other terms as for CSF are sometimes used, EXCEPT „xanthrochromic‟  Cell count:  same as for CSF  Differential:  any cell in peripheral blood,  mesothelialcells, 17  malignant cells  SUMMARY  Serous fluids are serum-like ultrafiltrates of plasma  Effusions are excessive accumulations of fluids (can occur in the pericardium, pleural and abdominal cavities).  Laboratory testing is required to differentiate exudates from transudates.  Laboratory testing:  Hematology (physical properties, cell counts and differential)  Chemistry (serum & fluid values are compared)  Serology –rarely 18  Cytology –if suspicious cells are seen during differential