1 STOOL AND URINE

• Urine and Stool are two out of the three most common specimens, with blood being the third
• Urine and Stool are non-invasively collected; you don't need to insert something to collect them
• Urine and Stool specimens are not collected by the medical technologists themselves; they are collected by patients or other healthcare practitioners
• Urinalysis


  The test used for urine, under Clinical Microscopy
• Characteristics of a urine specimen

  • Readily available and easily collected
  • Urine contains information about many of the body's major metabolic functions
• While stool is a good indicator of gastrointestinal health, it is being produced by the large intestines
• Testing of urine is commonly performed in an expeditious (fast), reliable, safe, and cost-effective manner
• Reasons for Urinalysis

  • Disease diagnosis
  • Screening asymptomatic populations for undetected disorders
  • Monitoring progress of disease and effectiveness of therapy
• Urine Formation

  Ultrafiltrate of Plasma, formed at the kidneys
• Average daily urine output

  1200mL-1500mL (600 to 2000mL is also normal)
• Terminologies related to urine output

  • Normal Daily Output (1200-1500mL)
  • Oliguria (decreased urine output: 400mL/day)
  • Anuria (cessation of urine flow)
  • Nocturia (increased excretion of urine during the night)
  • Polyuria (increased urine output: >2.5L/day)
• Urine is normally 95% water and 5% solutes (organic and inorganic)
• Organic Solutes in Urine (24-hour specimen)

  • Urea (25.0 - 35.0g)
  • Creatinine (1.5g)
  • Uric Acid (0.4 - 0.1g)
  • Hippuric Acid (0.7g)
  • Others (2.9g)
• Inorganic Solutes in Urine (24-hour specimen)

  • NaCl (15.0g)
  • Potassium (3.3g)
  • Sulfate (2.5g)
  • Phosphate (2.5g)
  • Ammonium (0.7g)
  • Magnesium (0.1g)
  • Calcium (0.3g)
• Urine Collection

  • Urine is classified as a BIOHAZARD
  • Observe standard precautions
  • Requisition forms are required
  • Containers for routine urinalysis have specific requirements
• Medical technologists do not collect the urine specimen themselves; they instruct the patient or other medical practitioner on how to properly collect the urine
• Types of Urine Specimen

  • Random
  • First Morning
  • Pregnancy Test
  • Orthostatic Protein
  • Fasting
  • 24-hour (or timed)
  • Catheterized
  • Midstream clean-catch
  • Suprapubic Aspiration
  • Cytology
• Random Urine


  Any urine specimen that the patient has collected at any time of the day; good enough for routine screening
• First Morning Urine


  More concentrated, better for routine screening
• 24-Hour Specimen


  For quantitative measurements, patients are given a large container with preservative
• Suprapubic Aspiration


  Commonly done on pediatrics or for patients that have difficulty urinating; needle is introduced through abdomen into bladder; most sterile urine specimen
• Catheterized Specimen


  Collected under sterile conditions by passing a sterile hollow tube through the urethra into the bladder
• Midstream Clean-Catch


  Alternative to catheterized specimens; less traumatic and less contaminated by epithelial cells and bacteria
• Types of Tampering in Urine Drug Sample Collection

  • Adulteration (adding other chemicals)
  • Substitution (using another urine sample)
  • Dilution (adding water to reduce drug contents)
• Urine Drug Sample Collection

  • Chain of Custody (documentation of sample handling)
  • May be "witnessed" or "unwitnessed"
  • 30-45mL of urine is collected
  • Temperature, pH, color, and specific gravity of urine will be tested immediately
• Urine Preservatives

  • Refrigeration (2-8 C)
  • Toluene
  • Sodium Fluoride
  • Formalin
  • Phenol
• Feces (Stool) is helpful in the evaluation of gastrointestinal disorders
• Purposes of Stool Examination

  • Presence of intestinal parasites and their eggs
  • Fat and urobilinogen content
  • Presence of pathogenic bacteria and viruses
  • Presence of occult (hidden) blood