Physical Examination of Urine Flashcards
The normal urine color includes
pale yellow → yellow → dark yellow
Pigment responsible for the yellow color of urine
Urochrome
Characteristics of urochrome
Lipid soluble pigment
Major pigment; darkens on exposure to light
Continuously produced but is dependent on the body’s metabolic state
Conditions that can cause increased urochrome production
Thyroid conditions
Fasting
Urine stands at room temperature
Pink pigment, most evident in specimens that have been refrigerated, resulting in the precipitation of amorphous urates (“brick dust”)
Uroerythrin
Orange brown color, an oxidation product of the normal urinary constituent urobilinogen
Urobilin
The concentration of a normal urine specimen can be estimated by urine color. True or False?
True
The appearance of yellow foam when urine is shaken is caused by
Bilirubin
Antibiotic administered for urinary tract infections that causes dark yellow urine
Nitrofurantoin
Antibiotic administered for urinary tract infections that causes orange-yellow urine
Phenazopyridine (Pyridium)
Cause of colored foam in acidic urine
Bilirubin oxidized to biliverdin
Cause of green urine
Pseudomonas infection
Cloudy urine with visible RBCs under microscope
Hematuria
Clear red urine due to intravascular hemolysis
Hemoglobinuria
Clear red urine due to muscle damage
Myoglobinuria
Cloudy specimen with RBCs, mucus, and clots is due to
Menstrual contamination
Urine color of patient with Alkaptonuria
Brown
Urine color of patient taking antihypertensive drugs
Black
Cause of purple-staining in catheter bags
Bacterial infection caused by Klebsiella or Providencia species
General term that refers to the “Transparency or Turbidity”
Clarity
Normal urine clarity
Clear
Faint cloud in urine after standing due to WBCs, epithelial cells and mucus
Nubecula/Nabeculae
How to visually examine urine clarity
Hold the specimen in front of a light source. View through a newspaper print
No visible particulates, transparent
Clear
Few particulates, print easily seen through urine
Hazy
Many particulates, print blurred through urine
Cloudy
Print cannot be seen through urine
Turbid
May precipitate or be clotted
Milky
Indication of clear urine clarity
All solutes present are soluble
Cause of hazy urine
RBC & WBC
Cause of cloudy urine
Crystals, Microbes, Fat, epithelial cells
Cause of turbid urine
Mucus, mucin, pus, radiographic dye, semen, contaminants
Cause of milky urine
Fats or lymph (lipiduria and chyluria)
Odor of freshly voided urine
Faint aromatic odor
Odor of old urine
Ammonia odor
Responsible for the characteristic ammonia odor
Breakdown of urea
Normal urine odor
Aromatic
Cause of maple syrup odor
MSUD
Cause of mousy odor
Phenylketonuria
Cause of rancid odor
Tyrosinemia
Cause of sweaty feet odor
Isovaleric acidemia
Indication of odorless urine
Acute tubular necrosis
Cause of rotting fish odor
Trimethylaminuria
Cause of swimming pool odor
Hawkinsinuria
Cause of sulfur odor
Cystinuria
Density of a solution compared with the density of a similar volume of distilled water at a similar temperature
Specific gravity
S.G. is influenced by
Number and size of particles
The specific gravity of the plasma filtrate entering the glomerulus
1.010
Isosthenuric S.G.
1.010
Hyposthenuric S.G.
<1.010
Hypersthenuric S.G.
> 1.010
S.G. of normal random specimen
1.002-1.035
Indication of S.G. <1.002
Not urine
S.G. of most random specimens fall between
1.015-1.030
S.G. >1.040 is seen in
Patients who have recently undergone an intravenous pyelogram (Radiographic contrast dye /X-ray film, Dextran, and other Plasma expanders)
It determines the concentration of dissolved particles in a specimen by measuring refractive index
Refractometer
Comparison of the velocity of light in air and in a solution (urine)
Refractive index
Temperature corrections are necessary when using refractometer. True or False?
Not necessary
Corrections for glucose and protein
Subtract 0.004 /gram of glucose
Subtract 0.003 /gram of protein
S.G. of distilled water
1.000
When refractometer is calibrated using 5% NaCl, S.G. should read
1.022 ± 0.001
When refractometer is calibrated using 9% sucrose, S.G. should read
1.034 ± 0.001
Based on the principle that the frequency of a sound wave entering a solution change in proportion to the density of the solution
Harmonic Oscillation Densitometry
Principle of testing urine S.G.
Change in the pKa (dissociation constant) of a polyelectrolyte in an alkaline medium
S.G. reading is not affected by radiographic contrast dye, protein, and glucose when using reagent strip. True or False?
True
Consists of a weighted float attach to a scale that has been calibrated in terms of urine specific gravity
Hydrometer
The calibrated temperature of hydrometer
20 C
Correction for S.G. when using Hydrometer
Add 0.001 for every 3C above the calibration temp.
Subtract 0.001 for every 3C below the calibration temp.
Subtract 0.004 for every 1 gram of glucose
Subtract 0.003 for every 1 gram of protein
When hydrometer is calibrated using potassium sulfate, S.G. should read
1.015
