Analysis of body fluids

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Analysis of body fluids

  1. 1. Analysis of Body Fluids Part-1 Dr. Gangadhar Chatterjee JRII Dept. of Biochemistry
  2. 2. Fluid accumulation in the pleural, pericardial, and peritoneal cavities is known as a serous effusion. potential space lined by mesothelium of the visceral and parietal pleurae. The fluid is plasma filtrate derived from capillaries of the parietal pleura. Produced continuously at a rate dependent on capillary hydrostatic pressure, plasma oncotic pressure, and capillary permeability.
  3. 3. SPECIMEN COLLECTION THORACENTESIS Except for an EDTA tube for total and differential cell counts, the specimen should be collected in heparinized tubes to avoid clotting. If malignancy, fungal or mycobacterial infection suspected, all remaining fluid (≥100 mL) should be submitted to maximize the yield of stains and culture.
  4. 4. TRANSUDATES AND EXUDATES
  5. 5. Light’s Criteria Pleural fluid is exudate if one or more:    Pleural LDH/Serum LDH > 0.6* -ORPleural protein/Serum protein > 0.5 -ORPleural LDH > 2/3 upper limit of normal (serum) Usually > 200 IU Absence of ALL: transudate Sensitivity 99%, Specificity 98%
  6. 6. GROSS EXAMINATION -Transudates typically clear, pale yellow to straw-colored, and odorless and do not clot - traumatic tap suggested by uneven blood distribution, fluid clearing with continued aspiration, or formation of small blood clots. -True chylous effusions produced by leakage from the thoracic duct resulting from obstruction by lymphoma, carcinoma, or traumatic disruption
  7. 7. Pseudochylous or chyliform effusions may accumulate gradually through the breakdown of cellular lipids in long standing effusions such as rheumatoid pleuritis, tuberculosis, or myxedema.
  8. 8. MICROSCOPIC EXAMINATION -Cell Counts -Differential Leukocyte Count and Cytology
  9. 9. CHEMICAL ANALYSIS -Protein pleural fluid total protein or albumin has little clinical value -Glucose Decreased pleural fluid glucose ie. level below 60 mg/dL or a pleural fluid/serum glucose ratio less than 0.5, most consistent and dramatic in rheumatoid pleuritis and grossly purulent parapneumonic exudates
  10. 10. -Lactate useful adjunct in the rapid diagnosis of infectious pleuritis. -Enzymes Amylase elevations above the serum level (usually 1.5–2.0 or more times greater) indicate the presence of pancreatitis, esophageal rupture, or malignant effusion LDH Pleural fluid LD levels rise in proportion to the degree of inflammation.
  11. 11. ADA Significantly increased in tuberculous pleuritis. ADA levels of 40 U/L or greater are present in about 99.6% of patients with verified tuberculous pleuritis Interferon-γ significantly increased in then pleural fluid of patients with tuberculous pleuritis. The sensitivity of levels of 3.7 IU/L or greater is 99%, and the specificity is 98%.
  12. 12. -pH highest diagnostic accuracy in assessing the prognosis of parapneumonic (pneumoniarelated) effusions. parapneumonic exudate with a pH greater than 7.30 generally resolves with medical therapy alone. A pH less than 7.20 indicates complicated parapneumonic effusion (loculated or associated with empyema), requiring surgical drainage.
  13. 13. - Lipids ( Cholesterol) - C-reactive protein - Tumour markers - Immunological tests - Microbiological tests
  14. 14. Pericardial Fluid
  15. 15. SPECIMEN COLLECTION obtained by pericardiotomy following limited thoracotomy or by pericardiocentesis (sterile needle aspiration). Normal pericardial fluid is pale yellow and clear. Large effusions (>350 mL) most often caused by malignancy or uremia, or may be idiopathic.
  16. 16. postpericardiotomy syndrome hallmarked by the development of fever, pleuritic chest pain, and other signs of pleural, pericardial, and, less often, lung inflammation.  Exudative pleural effusions develop in more than 80% of cases, often serosanguineous to hemorrhagic and typically have a pH greater than 7.4 and a normal glucose level.
  17. 17. Peritoneal Fluid
  18. 18. Largest serosal sac in the body and secretes approximately 50 ml of fluid per day.
  19. 19. SAAG Serum-Ascites Albumin Gradient = serum albumin – ascites albumin > 1.1 = portal hypertension < 1.1 = non-portal hypertension probably the best single method to differentiate an ascitic exudate from a transudate
  20. 20. SPECIMEN COLLECTION Paracentesis ( so called tapping) Diagnostic Peritoneal Lavage Peritoneal Dialysis Peritoneal Washings
  21. 21. Spontaneous Bacterial Peritonitis (SBP) Spontaneous bacterial peritonitis (SBP) is an acute bacterial infection of ascitic fluid. Patients with cirrhosis and ascites carry a 10% annual risk of ascitic fluid infection
  22. 22. Predisposing factor may be :  Intestinal bacterial overgrowth  Impaired phagocytic function  Low serum and ascites complement levels  Decreased activity of the reticuloendothelial system
  23. 23. Etiologic agents (>90% intestinal flora)  Three forth of infections are due to aerobic gramnegative organisms (50% of these being Escherichia coli)  One fourth are due to aerobic gram-positive organisms (19% streptococcal species).  Anaerobic organisms are rare (1%) because of the high oxygen tension of ascitic fluid.
  24. 24. Clinical presentation and diagnosis of ascitic fluid infection  A broad range of symptoms and signs are seen in SBP. A high index of suspicion must be maintained when caring for patients with ascites, particularly those with acute clinical deterioration.  Completely asymptomatic cases in as many as 30% of patients.  Fever and chills occur in as many as 80% of patients.  Abdominal pain or discomfort is found in 70% of patients.  Worsening or unexplained encephalopathy  Diarrhea
  25. 25.  Diagnostic paracentesis and direct inoculation of routine blood culture bottles at the bedside with 10 mL of ascitic fluid must be performed.  The results of aerobic and anaerobic bacterial cultures, used in conjunction with the cell count, prove the most useful in guiding therapy for those with SBP. An ascitic fluid neutrophil count of >500 cells/mL is the single best predictor of SBP.
  26. 26. Ascitic fluid examination Appearance: The gross appearance of the ascitic fluid can be helpful in the differential diagnosis. Turbid or cloudy: infected fluid. Milky: Triglyceride concentration of greater than 200mg/dl (often greater than 1000mg/dl), malignancy is usually MC cause, but cirrhosis may present with chylous fluid. Pink or Bloody: Pink fluid usually traumatic tap. Frankly bloody may occur in hepatocellular carcinoma, or other malignancy related ascites. Brown: Deeply jaundiced pts may present with brown ascitic fluid, which may represent gallbladder rupture or perforated duodenal ulcer.
  27. 27. • Total protein: Helpful in diagnosing spontaneous bacterial peritonitis Pts with a value<1 g/dl protein and glucose of <50mg/dl have high risk of SBP • Cytology: for malignant cells • Amylase: to exclude pancreatic ascites
  28. 28. Elevated alkaline phosphatase (ALP) levels greater than 10 U/L in diagnostic peritoneal lavage fluid are very useful in predicting hollowvisceral injury in patients who would otherwise not undergo laparotomy (specificity 99.8%, sensitivity 94.7%) peritoneal fluid LD has higher diagnostic sensitivity (87%) and diagnostic accuracy (90%) than serum LD ADA is commonly used in endemic areas to identify patients with tuberculous peritonitis
  29. 29. Lactate Patients with hollow viscous perforation, gangrenous intestine, peritonitis, or intraabdominal abscess have a peritoneal fluid minus plasma lactate level of at least 13.5 mg/dL (1.5 mmol/L), which separates these patients completely from those with other conditions producing acute abdominal problems.
  30. 30. THANK U

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