PHYSICAL EXAMINATION OF URINE

• Epithelial cells


  Cells that line the internal and external surfaces of the body
• Mucus threads


  Sticky, stringy material found in urine
• Types of crystals

  • Amorphous
  • Crystals
• Components found in urine and body fluids

  • Epithelial cells
  • Mucus threads
  • Crystals
  • Casts
  • Bacteria
  • WBC
  • RBC
  • Yeast
  • Sperm cells
• Urochrome


  Pigment that causes the yellow color of urine
• Urochrome increases in

  Thyroid conditions, fasting states, and stands at room temperature
• Other pigments

  Uroerythrin and urobilin
• Common urine colors in the laboratory

  • Pale yellow
  • Yellow
  • Dark yellow

  
• The yellow color of urine is caused by the presence of a pigment, which Thudichum named urochrome
• Causes of urine color

  • Colorless
  • Pale yellow
  • Dark yellow
  • Orange-yellow
  • Yellow-green
  • Green
  • Blue-green
  • Pink
  • Red
  • Port wine
  • Red-brown
  • Brown
  • Black
• CLARITY TERMS

  • Clear- no visible particulates, transparent
  • Hazy- few particulates, print easily seen through urine
  • Cloudy- many particulates, print blurred through urine
  • Turbid- print cannot be seen in urine
  • Milky- may precipitate or be clotted
• Non-pathologic turbidity is a hazy but normal urine caused by the presence of squamous epithelial cells and mucus, as well as other causes like semen, fecal contamination, radiographic contrast media, talcum powder, and vaginal creams
• Pathologic turbidity is caused by RBC, WBC, bacteria, and yeast
• Isosthenuric


  Specific gravity of 1.010
• Hyposthenuric


  Specific gravity below 1.010
• Hypersthenuric


  Specific gravity above 1.010
• Current urine specific gravity measurement methods

  • Refractometry
  • Osmolality
  • Reagent strip
• Refractometry


  Determines the concentration of dissolved particles in a specimen by measuring refractive index
• Osmolality


  Measures the number of solute particles per unit of solvent, affected only by the number of particles present
• Reagent strip


  Based on the change in pKa (dissociation constant) of a polyelectrolyte in an alkaline medium
• Causes of urine odor

  • Aromatic (normal)
  • Foul, ammonia-like (bacterial decomposition, urinary tract infection)
  • Fruity, sweet (ketones)
  • Maple syrup (maple syrup urine disease)
  • Mousy (phenylketonuria)
  • Rancid (tyrosinemia)
  • Sweaty feet (isovaleric acidemia)
  • Cabbage (methionine malabsorption)
  • Bleach (contamination)
• Refractive index


  is a comparison of the velocity of light in air with the velocity of light in a solution.
• Osmolarity of a solution can be determined by measuring a property that is mathematically related to the number of particles in the solution (colligative property) and comparing this value with the value obtained from the pure solvent.
• As the specific gravity increases, the indicator changes from blue(1.000), to shades of green, to yellow (1.030).
• Increased concentration urine= increased H+ ions released = decreased pH
• Indicator bromthymol blue on the reagent pad measures the pH
• Freshly voided urine


  faint aromatic odor
• Long standing specimen


  the odor of ammonia becomes more prominent
• CURRENT URINE SPECIFIC GRAVITY MEASUREMENT

  Method- Principle

  Refractometry- Refractive index

  Osmolality- Changes in colligative properties by particle

  number

  Reagent strip- pKa changes of a polyelectrolyte by ions present
• COLORLESS


  Commonly observed with random specimens
• PALE YELLOW


  • Increased 24-hour volume
  • low specific gravity
  • Elevated specific gravity
  • positive glucose test result
  • Recent fluid consumption
• DARK YELLOW


  • May be first morning specimen
  • Fever or burns
  • Yellow foam when shaken
  • positive chemical test results for bilirubin
  • Antibiotic administered for urinary tract infections
• ORANGE YELLOW


  • Drug Phenazopyridine (Pyridium) commonly administered for urinary tract infections
• YELLOW-GREEN


  • Colored foam in acidic urine
  • false-negative chemical test results for bilirubin
• GREEN


  • Positive urine culture
  • RBCs visible microscopically
  • Clear urine with positive chemical test results for blood; intravascular hemolysis
• BLUE-GREEN


  • Antidepressant, Muscle relaxant, Bacterial infections, intestinal disorders
• PINK


  • Cloudy urine with positive chemical test results for blood
• RED


  • Clear urine with positive chemical test results for blood; intravascular hemolysis
• PORT WINE


  • Due porphyrins excreted in the urine. (Porphyria)
• RED-BROWN


  • Seen in acidic urine after standing; positive chemical test result for blood