OTHER NON BLOOD SAMPLE

• Feces (Stool)

  • Routine fecal examination includes macroscopic, microscopic, and chemical analyses for the early detection of gastrointestinal (GI)bleeding, liver and biliary duct disorders, maldigestion/malabsorption syndromes, pancreatic diseases, inflammation, and causes of diarrhea and steatorrhea.
• Normal fecal specimen contains: bacteria, cellulose, undigested food stuffs, GI secretions, bile pigments, cells from the intestinal walls, electrolytes, and water
• Feces (Stool)

  • Approximately 100 to 200 g of feces is excreted in a 24-hour period
• Feces (Stool)

  • approximately 9000 mL of ingested fluid, saliva, gastric, liver, pancreatic, and intestinal secretions enter the digestive tract each day. Under normal conditions, only between 500 to1500 mL of this fluid reaches the large intestine, and only about 150 mL is excreted in the feces.
• Specimen Collection:

  • normally collected in clean, dry, wide-mouthed containers that should be sealed and sent to the laboratory immediately after collection.
  • Special containers with preservative are available for ova and parasite collection
• Specimen Collection:

  • Preserved specimens can usually be kept at roomtemperature.
  • Large gallon containers, similar to paint cans, are used for24-, 48-, and 72-hour stool collections for fecal fat and urobilinogen; these specimens must normally be refrigerated throughout the collection period
• Macroscopic Screening

  • Color and Appearance
• Macroscopic Screening (Color and Appearance)

  • The first indication of GI disturbances can often be changes in the brown color and formed consistency of the normal stool.
  • Appearance: watery consistency present in diarrhea; small, hard stools seen with constipation; and slender, ribbon-like stools, which suggest obstruction of the normal passage of material through the intestine.
• Color: Black, Possible Cause: Upper Gl bleeding
• Color: Black, Possible Cause: Iron therapy
• Color: Black, Possible Cause: Charcoal
• Color: Black, Possible Cause: Bismuth (antacids)
• Color: Red, Possible Cause: Lower Gl bleeding
• Color: Red, Possible Cause: Beets and food coloring
• Color: Red, Possible Cause: Rifampin
• Color: Pale yellow, white, gray, Possible Cause: Bile-duct obstruction
• Color: Pale yellow, white, gray, Possible Cause: Barium sulfate
• Color: Green, Possible Cause: Biliverdin/oral antibiotics
• Color: Green, Possible Cause: Green vegetables
• Color: bulky/frothy, Possible Cause: Bile-duct obstruction
• Color: bulky/frothy, Possible Cause: Pancreatic disorders
• Color: Ribbon-like, Possible Cause: Intestinal constriction
• Color: Mucus or blood-streaked mucus, Possible Cause: Colitis
• Color: Mucus or blood-streaked mucus, Possible Cause: Dysentery
• Color: Mucus or blood-streaked mucus, Possible Cause: Malignancy
• Color: Mucus or blood-streaked mucus, Possible Cause: Constipation
• Chemical Testing of Feces (Occult Blood)

  • Annual testing for occult blood has a high positive predictive value for detecting colorectal cancer in the early stages
• Guaiac-Based Fecal Occult Blood Tests

  • most frequently used screening test for fecal blood
  • based on detecting the pseudoperoxidase activity of hemoglobin
• Feces (Stool)(Quantitative Fecal Fat Testing)

  • quantitative fecal analysis requires the collection of at least a 3-dayspecimen. The patient must maintain a regulated intake of fat (100 g/d) before and during the collection period. The specimen is collected in a large, pre-weighed container. Before analysis, the specimen is weighed and homogenized. Refrigerating the specimen prevents any bacterial degradation.
  • confirmatory test for steatorrhea
• Steatorrhea (fecal fat)

  • Absence of bile salts that assist pancreatic lipase in the breakdown and subsequent reabsorption of dietary fat (triglycerides) produces an increase in stool fat.
• Cerebrospinal Fluid

  • major fluid in the body
  • provides a physiologic system to supply nutrients to the nervous tissue, remove metabolic wastes, and produce a mechanical barrier to cushion the brain and spinal cord against trauma
• Cerebrospinal Fluid

  • CSF is produced in the choroid plexuses of the two lumbar ventricles and the third and fourth ventricles. In adults, approximately 20 mL of fluid is produced every hour. The fluid flows through the subarachnoid space located between the arachnoid and pia mater
• Cerebrospinal Fluid

  • Body maintains a volume of 90 to 150 mL in adults and 10 to 60 mL in neonates
• Cerebrospinal Fluid (Specimen Collection)

  • CSF is routinely collected by lumbar puncture between the third, fourth, or fifth lumbar vertebra
  • Specimens are obtained by a physician; most often through lumbar puncture (spinal tap)
• Cerebrospinal Fluid (Specimen Collection)

  • Tube No. 1: Chemistry and Immunology
  • Tube No. 2: Microbiology
  • Tube No. 3: Hematology (Cell counts)
  • *A Fourth tube may be drawn for the microbiology lab
• Cerebrospinal Fluid (Appearance)

  • Normal CSF: Clear, Crystal-clear and Colorless
  • The major terminology used to describe CSF appearance includes crystal-clear, cloudy or turbid, milky, xanthocromic, and hemolyzed/bloody.
• Xanthochromia

  • used to describe CSF supernatant that is pink, orange, or yellow.
• Cerebrospinal Fluid (Appearance)

  • Tube No. 1: Chemistry and Immunology/Serology
  • Tube No. 2: Microbiology
  • Tube No. 3: Hematology (Cell counts)
  • *A Fourth tube may be drawn for the microbiology lab
• Appearance: Crystal Clear, Cause: N/A, Major Significance: Normal
• Appearance: Hazy, turbid, milky, cloudy, Cause: WBCs, Major Significance: Meningitis