Chapter 5 Flashcards
Physical examination of urine includes- (3)
-color
-clarity
-specific gravity
Physical examination of urine results provide- (2)
-preliminary info
-correlation with other chemicals & microscopic results
Urine color analysis provides preliminary info concerning disorders such as- (5)
-glomerular bleeding
-liver disease
-inborn errors of metabolism
-UTI
-renal tubular function
Urine color ranges from-
Colorless to black
Normal variations of urine color are caused by- (4)
-normal metabolic functions
-physical activity
-ingested materials
-pathological conditions
Normal urine color common terminology- (3)
-pale yellow
-yellow
-dark yellow
Normal urine color should be consistent within-
Lab
Urochrome is pigment causing-
Yellow color
Urochrome is normally excreted-
At a constant rate
Urochrome is increased in- (2)
-thyroid disorders
-fasting
Urochrome increases when-
Specimen sits at room temp
Urochrome provides estimate of-
Body hydration
Normal urochrome colors can be-
Pale yellow to dark yellow
Additional pigments of normal urine color- (2)
-uroerythrin
-urobilin
Color changes of urine occur in-
Older specimens
Pigment in uroerythrin-
Pink
Pink pigment in uroerythrin is caused when-
Attaches to amorphous urates formed in refrigerated specimens
Urobilin color in older specimens-
Orange-brown
Urobilin oxidation of normal constituent-
Urobilinogen
Common abnormal urine colors- (4)
-dark yellow/amber/orange
-red/pink/brown
-brown/black
-blue/green
Normal dark yellow & amber urine indicates-
Concentrated urine
Abnormal dark yellow & amber urine indicates-
Bilirubin
In dark yellow & amber urine, bilirubin produces-
Yellow foam when shaken
In dark yellow & amber urine, normal urine produces-
Small amount of white foam caused by protein
In dark yellow & amber urine, bilirubin indicates-
Possible hep virus present
In dark yellow & amber urine, photooxidation of large amounts of urobilinogen produces-
Yellow-orange urine (no foam when shaken)
In dark yellow & amber urine, Photooxidation of bilirubin to biliverdin produces-
Yellow-green urine
Common cause of red urine-
Blood
Blood in urine color can range from-
Pink to brown
Pink color in the urine indicates-
Small amount of blood
Brown color in the urine indicates-
Oxidation of hemoglobin to methemoglobin
Methemoglobin RBCs remain in-
Acid urine
Fresh brown urine specimen can indicate-
Glomerular bleeding
Cloudy red urine indicates-
RBCs
Clear red urine indicates-
Hemoglobin/myoglobin
Hemoglobin in urine- (3)
-in vivo lysis of RBCs
-patient’s plasma will also be red
-consider in vitro lysis
Myoglobin in urine- (3)
-breakdown of skeletal muscle
-fresh urine is often more reddish/brown
-patient’s plasma is clear
Port wine colored urine indicates-
Oxidation of porphobilinogen to porphyrias
Nonpathic red urine indicates- (3)
-Menstrual contamination
-Pigmented foods
-Medications (rifampin, pheno-compounds)
Generally susceptible people in alkaline urine-
Fresh beets
Found in acid urine-
Black raspberries
Additional testing for brown/black urine specimens that- (2)
-turn black after standing at room temp
-test negative for blood
Melanin in brown/black urine- (2)
-Excess in malignant melanoma
-Oxidation of melanogen to melanin
Homogentisic acid in brown/black urine- (2)
-Black color in alkaline urine
-Alkaptonuria
Clorets for brown/black urine- (5)
-Medications
-levodopa
-methyldopa
-phenol derivatives
-flagyl & furadantin
Pathogenic cause of blue/green urine-
Urinary & intestinal bacterial infections
Urinary bacterial infections-
Pseudomonas infection
Intestinal bacterial infection causes-
increased urinary indican oxidizing to indigo blue
Clorets for green urine- (2)
-B vitamin
-asparagus
Clorets for blue urine- (5)
-medications
-Robaxin
-Indocin
-Tivorbex
-Elavil & Diprivan
Catheter bags in blue/green urine-
Purple color from Klebsiella & Providencia
Can cause green urine-
IV phenol medications
Clarity refers to-
Transparency or turbidity of a specimen
Visual examination for clarity of urine- (2)
-Gently swirl specimen in a clear container in front of a good light source
-Specimen should be in a clear container
Color & clarity are routinely done at-
The same time
Terminology used to report clarity of urine- (5)
-clear
-hazy
-cloudy
-turbid
-milky
Clear urine clarity-
No visible particulates, transparent
Hazy urine clarity-
Few particulates, print easily seen through urine
Cloudy urine clarity-
Many particulates, print blurred through urine
Turbid urine clarity-
Print cannot be seen through urine
Milky urine clarity-
May precipitate or be clotted
Freshly voided urine is usually-
Clear, particularly if it is a midstream specimen
may cause a white cloudiness in an alkaline urine specimen- (2)
-amorphous phosphates
-carbohydrates
Nonpathogenic turbidity in hazy female specimens-
With squamous epithelial cells & mucus
Nonpathogenic turbidity in bacterial growth-
In nonpreserved specimens
Nonpathogenic turbidity in refrigerated specimens with- (3)
-precipitated amorphous phosphates (white)
-carbonates (white)
-urates (pink)
Nonpathogenic Turbidity contamination- (5)
-fecal
-talc
-semen
-vaginal creams
-IV contrast media
Most common Pathological Turbidity- (3)
-RBCs
-WBCs
-bacteria
Pathological Turbidity also include- (5)
-nonsquamous epithelial cells
-yeast
-trichomonads
-abnormal crystals
-lymph fluid
-lipids
The extent of turbidity should correspond to-
the amount of material observed in the microscopic examination
In pathological turbidity, clarity is on of the criteria considered in determining-
the necessity of performing a microscopic examination
Specific gravity evaluates-
Urine concentration
Specific gravity determines-
if specimen is concentrated enough to provide reliable chemistry results
Specific gravity definition-
the density of a solution compared with the density of an equal volume of distilled water at the same temperature
Isosthenuric SG-
1.010
Isosthenuric is the standard gravity of-
Plasma ultrafiltrate
Hyposthenuric SG-
Lower than 1.010
Hypersthenuric SG-
Higher than 1.010
Normal random specimen range SG-
1.002 - 1.035
Most common specimen range SG-
1.015 - 1.025
SG that may not be considered urine-
Below 1.002
Refractometer measures-
velocity of light in air versus velocity of light in a solution
Refractometer concentration changes-
the velocity and angle at which the light passes through the solution
Prism in the Refractometer determines-
the angle that light is passing through the urine and converts angle to calibrated viewing scale
Refractometer advantages- (3)
-Temperature compensation not needed
‒Light passes through temperature-compensating liquid
‒Compensated between 15°C and 38°C
Refractometer specimen size-
One drop
Corrections for glucose & protein in Refractometer- (2)
-Subtract 0.003 for each gram of protein present
-Subtract 0.004 for each gram of glucose present
Refractometer process- (3)
-Drop of urine placed on prism
-Focus on light source, and read scale
-Wipe off prism between specimens
Calibration of a Refractometer- (3)
-Distilled water should read 1.000; adjust set screw if necessary
-5% NaCl should read 1.022 ± 0.001
-9% sucrose should read 1.034 ± 0.001
Osmolality is a more representative measure of-
renal concentrating ability can be obtained
Osmolality SG depends on-
the number of particles present in a solution and the density of these particles
Osmolality is affected only by-
The number of particles present
Osmolality substances of interest are small molecules- (3)
-Sodium
‒Chloride
‒Urea
Unit of measure of Osmolality-
mOsm (milliosmole)
Osmolality Glu-
180 g/osm (C + H + O)
Osmolality NaCl-
58.5 g/osm (Na + Cl)
In Osmolality, 1 g molecular weight of a substance divided by-
the number of particles into which it dissociates (= to MW of substance)
Osmolality of a solution can be determined by-
measuring a property that is mathematically related to the number of particles in the solution (colligative property)
Changes in colligative properties- (4)
-Lower freezing point
-Higher boiling point
-Increased osmotic pressure
-Lower vapor pressure
Measuring osmolality in the urinalysis laboratory requires an
Osmometer
Osmometer is an additional step in-
the routine urinalysis procedure
Automated Osmometer utilizes-
freezing point depression to measure osmolality
The reagent strip reaction is based on the change in-
pKa (dissociation constant) of a polyelectrolyte in an alkaline medium
Reagent strips release H ions in direct proportion to-
number of ions in the solution
The more hydrogen ions released in reagent strip SG-
the lower is the pH
Indicator bromothymol-LS blue on the reagent pad measures-
Changes in pH
Reagent strip SG Indicator changes from-
blue (1.000 [alkaline]), through shades of green, to yellow (1.030 [acid])
Reagent strip SG isn’t affected by-
Nonionizing substances
Odor in fresh urine-
Faintly aromatic
Odor in older urine-
Ammonia
Odor in metabolic disorders- (3)
-urine disease (maple syrup)
-ketosis (fruity)
-infection (ammonia/unpleasant)
Food odor in urine- (3)
-garlic
-onions
-asparagus (genetic: only certain people can smell asparagus, but all produce odor)
Aromatic urine odor cause-
Normal
Foul, ammonia-like urine odor cause- (2)
-bacterial decomposition
-UTI
Fruity, sweet urine odor cause-
Ketones (diabetes mellitus, starvation, vomiting)
Maple syrup urine odor cause-
Maple syrup urine increase
Mousy urine odor cause-
Phenylketonuria
Rancid urine odor cause-
Tryosinemia
Sweaty feet urine odor cause-
Isovaleric acidemia
Cabbage urine odor cause-
Methionine malabsorption
Bleach urine odor cause-
Contamination