Introduction to Urinalysis Flashcards
Aqueous solution of various organic and inorganic substances
Urine
Substance may be either waste products resulting from body metabolism or products derived directly from the food eaten resulting from metabolism.
Urine
Urine is composed of ___ % water and ____% solids
95, 5
Why choose urine for urinalysis?
● It is readily available and easily collected.
● Contains information about the body’s major metabolic functions
● Inexpensive laboratory testing can be performed.
Why choose urine for urinalysis?
● It is most useful in ascertaining evidence of disease or disturbing function
of the kidneys
● Pathological lesion of the ureters, bladder or urethra
● In male, lesion of the prostate and seminal vesicles.
primary organic component. product of protein and amino acid metabolism
urea
product of creatine metabolism by muscles
creatinine
product of nucleic acid breakdown in food and cells
uric acid
primary inorganic component. found in combination with sodium (table salt) and mant other inorganic substances
chloride
primarily from salt varies by intake
Sodium
Combined with chloride
and other salt
Potassium
Combines with sodium
to buffer the blood
Phosphate
Regulates blood and
tissue fluid acidity
Ammonium
Combines with chloride,
sulfate, and phosphate
Calcium
Routine Screening
Random
Routine screening
Pregnancy tests
Orthostatic protein
First Morning
Quantitative chemical
tests
24-hour (or timed)
Bacterial culture
Catheterized
Routine screening
Bacterial culture
Midstream clean-catch
Bladder urine for
bacterial culture
Cytology
Suprapubic aspiration
Prostatic infection
Three-glass collection
Does not interfere with
chemical tests
Precipitates amorphous
phosphates and urates
Prevents bacterial growth
for 24 hours2
Refrigeration
Prevents bacterial growth and
metabolism
Boric acid
Interferes with drug and
hormone analyses
Boric acid
Keeps pH at about 6.0
Can be used for urine
culture transport
Boric acid
Excellent sediment preservative
Acts as a reducing agent,
interfering with chemical
tests for glucose, blood,
leukocyte esterase, and
copper reduction
Rinse specimen container
with formalin to preserve
cells and casts
Formalin (formaldehyde)
Is a good preservative for drug
analyses
Inhibits reagent strip tests
for glucose, blood, and
leukocytes
Formalin (formaldehyde)
Convenient when refrigeration
not possible
Have controlled concentration
to minimize interference
Commercial preservative
tablet
Check tablet composition
to determine possible
effects on desired tests
Commercial preservative
tablet
Contains collection cup,
transfer straw, culture and
sensitivity (C&S) preservative tube, or UA tube
Urine Collection Kits4
(Becton, Dickinson,
Rutherford, NJ)
Sample stable at room temperature (RT) for 48 hours; prevents bacterial growth and
metabolism
Do not use if urine is below
minimum fill line
Preservative is boric acid,
sodium borate and
sodium formate.
Keeps pH at about 6.0
Light gray and gray C&S
tube
Use on automated instruments
Must refrigerate within
2 hours
Round or conical bottom,
no preservative
Yellow UA Plus tube
Stable for 72 hours at RT; instrument-compatible
Must be filled to minimum
fill line.
Bilirubin and urobilinogen
may be decreased if
specimen is exposed to
light and left at RT
Preservative is sodium propionate, ethyl paraben,
and chlorhexidine;
round or conical bottom
Cherry red/yellow
Preservative Plus tube
Modified/darkened, Oxidation or reduction of metabolites
Color
Decreased, Bacterial growth and precipitation of amorphous material
Clarity
Increased, Bacterial multiplication causing breakdown of urea to ammonia
Odor
Increased, Breakdown of urea to ammonia by urease-producing bacteria/loss
of CO2
pH
Decreased, Glycolysis and bacterial use
Glucose
Decreased, Volatilization and bacterial metabolism
Ketones
Decreased, Exposure to light/photo oxidation to biliverdin
Bilirubin
Urobilinogen, Oxidation to urobilin
Urobilinogen
Increased, Multiplication of nitrate-reducing bacteria
Nitrite
Decreased, Disintegration in dilute alkaline urine
Red and white blood
cells and casts
Increased, Multiplication
Bacteria
Decreased, Loss of motility, death
Trichomonas
