Download Urine Testing

Urine Testing
Testing Urine
Unit 18:11
Urinalysis

Examination of urine
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Physical
Chemical
Microscopic
Physical Testing of Urine
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Observing color, transparency & specific
gravity
Color
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Normal: shade of yellow
Pale: dilute
Dark yellow, orange: concentrated
Cloudy red: hematuria
Clear-red: hemoglobin
Yellow or beer-brown: bilirubin
(bilirubinuria)
Transparency
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Normal: clear
Cloudy: pus, mucus
Milky: fats
Specific Gravity
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Normal: 1.005 to 1.030
Increased: dehydration, diabetes
mellitus
Decreased: kidney disease, diuretic,
increased fluid intake
Odor
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Normal: Faintly aromatic
Ammonia: old sample
Foul: infection
Sweet: DM, ketones
Chemical Testing
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pH
Protein
Glucose
Ketones
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Bilirubin
Urobilinogen
Blood
Microscopic Testing
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Examine formed
elements in urine
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Cells
Casts
Crystals
Amorphous debris
Which urine is best?
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Fresh, warm urine
Within 1 hour of
collection
Maybe refrigerated if
needed
Precautions
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Must use standard
precautions
Gloves, possibly
mask, eyewear
Discard urine in a
toilet
Dispose of specimen
in infectious waste
bag
Using Reagent Strips to Test
Urine
Unit 18:12
Reagent Strips

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Firm plastic strip
with chemical
reactants attached
to the strip
Color change
indicates presence
of substance &
amount of
substance
Storage

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Sensitive to light, heat, moisture
Store in dry, cool, dark area
Keep bottle closed
Precautions
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Don’t touch chemical reactant pads
May lead to inaccurate results or injure
the skin
pH
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Measure of acidity or alkalinity of urine
Normal: 5.5 to 8.0
Affected by:
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Diet
Medications
Kidney disease
Starvation
Protein
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Normal: none
Proteinuria may indicate kidney disease
Glucose
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Normal: none
May indicate Diabetes mellitus
Ketones
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End product of fat metabolism
Normal = none
May indicate:
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Diabetes mellitus
Fasting, dieting
High fat diet
Blood
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Normal = none
May indicate:
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Injury
Infection
Menstruation
Kidney disease
Bilirubin
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Break down product
of hemoglobin
Normal = none
May indicate:
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Liver disease
Urobilinogen
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Bilirubin converted by intestinal bacteria
Normal: small amounts
May indicate:
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Heart, spleen, liver or hemolytic disease
Spectrophotometers
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Automated strip
analyzer
More accurate than
human eye
Refrigerated samples
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Must be returned to room temperature
Time

Follow exact time for each chemical
reaction
Measuring Specific Gravity
Unit 18:13
Specific Gravity

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Density of a substance compared to the
density of water
Normal: 1.005 to 1.030
Urinometer
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Urine in a cylinder
and calibrated float
is placed in urine
with a spinning
motion
Urine collects at
curved line,
meniscus
Read of lower part
of meniscus
Refractometer

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One drop of urine
placed on device &
look through an
eyepiece
Calibrate with water
Preparing Urine for
Microscopic Examination
Unit 18:4
Urine Sediment
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Solid materials suspended in urine
What urine?
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Fresh, early morning first voided
specimen preferable
Examine immediately
Some elements disintegrate
Centrifuge
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Spin ~10-15 cc of
urine
Solid materials settle
at the bottom
Preparation
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Clear urine on top is poured off
Leave behind 1 cc in bottom
Examine immediately
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Drying occurs quickly & can distort
substances
lpf and hpf
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Low power field and high power field
Indicate amount seen in a field
RBCs
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Normal = none
May indicate:
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Kidney disease
Bleeding in urinary
tract
Menstruation
WBCs
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Normal = small
numbers
May indicate:
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infection
Bacteria
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Normal: none to
small amount
Large amount
indicates infection
Other infectious agents
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Fungi, yeasts
Parasites
Casts
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Formed in kidney
tubules during
kidney damage
Normal = none
Crystals
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Dependent on urine
pH