Introduction to Urinalysis Flashcards
“The testing of urine with procedures commonly
performed in an expeditious, reliable, accurate, safe,
and cost-effective manner.” (CLSI)
URINALYSIS
they continuously form urine as an ultrafiltrate
of plasma.
KIDNEYS
Ultrafiltration of plasma takes place in the?
glomerular capillaries
Reabsorption of water and filtered substances
essential to body function converts approximately
150,000 mL of filtered plasma
TRUE OR FALSE
FALSE
It reabsorbs 170,000mL not 150,000mL
the average daily urine output is?
1,200 mL
consists of urea and other organic and inorganic
chemicals dissolved in water.
Urine
Urine is normally 95% water and 5% solutes.
TRUE OR FALSE
TRUE
Urine is normally 95% water and 5% solutes.
These 5% solutes include:
Organic components;
Inorganic components.
(most abundant organic component), a metabolic
waste product produced in the liver from the
breakdown of protein and amino acids, accounts for
nearly half of the total dissolved solids in urine.
Urea
Aside from Urea other organic substances include primarily creatinine and uric acid, and other nitrogen-containing
compounds.
TRUE OR FALSE
TRUE
These are your main organic substances:
Urea
Creatinine
Uric Acid
Nitrogen-containing compounds
The major inorganic solid dissolved in urine is?
Chloride
principal salt in urine
sodium chloride salt
The major inorganic solid dissolved in urine is chloride followed by?
sodium and potassium
usually in the form of sodium chloride salt
excreted in the form of di-hydrogen phosphate
Calcium, phosphate
Small or trace amounts of many additional inorganic
chemicals are also present in the urine
TRUE OR FALSE
TRUE
Because other substances found in urine include
hormones, vitamins, and medications; may also contain formed elements such as cells, casts, crystals, mucus, and bacteria.
Primary organic component; product
of metabolism of protein and amino
acids
UREA
Product of metabolism of creatine by
muscles.
CREATININE
Product of breakdown of nucleic acid
in food and cells
URIC ACID
Primary inorganic component; found
in combination with sodium and many
other inorganic substances.
CHLORIDE
Primarily from salt, varies by intake.
SODIUM
Combined with chloride and other
salts.
POTASSIUM
Combines with sodium to buffer the
blood.
PHOSPHATE
Regulates blood and tissue fluid
acidity.
AMMONIUM
Combines with chloride, sulfate, and
phosphate.
CALCIUM
Refers to the 24-hr or Daily Output; the amount of urine
voided or excreted over a period of 24 hours
URINE VOLUME
Urine volume depends on the amount of _____ that the
kidneys excrete.
Water
is a major body constituent; therefore,
the amount excreted is usually determined by
the body’s state of hydration
Water
D/N (Day-to-Night) Ratio
2:3:1
Night output is 2 – 3x larger than the
Day output.
TRUE OR FALSE
FALSE
Day output is 2 – 3x larger than the
night output.
NORMAL DAILY URINE OUTPUT
RANDOM
600 – 2000 mL/day
NORMAL DAILY URINE OUTPUT
AVERAGE
1200 – 1500 mL/day (1.2 – 1.5 L/day)
Persistent production of large volumes of urine; an
abnormal increase in daily urine volume
Polyuria
2.5 L/day in adults;
2.5 – 3 mL/kg/day in children
Seen in cases of diabetes mellitus and diabetes
insipidus; differ in terms of specific gravity.
Polyuria
↑SG (hypersthenuria; due to
osmotic diuresis).
DIABETES MELLITUS
↓SG (hyposthenuria;
consistently within 1.002 –
1.003)
DIABETES INSIPIDUS
Failure in ADH secretion
(produces large amounts of
dilute urine).
DIABETES INSIPIDUS
Caused by a defect either in the pancreatic production of insulin or in the function of insulin, which results in an increased concentration of body glucose.
DIABETES MELLITUS
Results from a decrease in the production or function of ADH; thus, the water necessary for adequate body hydration is not reabsorbed from the plasma filtrate.
DIABETES INSIPIDUS
Fluid loss in both diabetes (Mellitus and Insipidus) diseases is compensated by increased ingestion of water (polydipsia), producing an even greater volume of urine. Polyuria is accompanied by increased fluid intake is often the first symptom of either disease.
TRUE OR FALSE
TRUE
increased ingestion of water
polydipsia
Persistent production of low volumes of urine; abnormal decrease in urine output
OLIGURIA
<400 mL/day in adults,
<1 mL/kg/hr in infants,
<0.5 mL/kg/hr in children
Identify this condition
Clinical Significance: Dehydration, renal insufficiency, poorly compensated heart disease, renal calculi (kidney stones), and kidney tumors
Characterized either by decreased renal blood flow or obstruction
OLIGURIA
Complete cessation of urine production; one of the main findings or manifestations of renal failure.
ANURIA
Almost all glomerular and tubulointerstitial disorders terminate in renal failure.
TRUE OR FALSE
TRUE
Identify this condition
Clinical Significance: Severe acute nephritis, tubular necrosis, Hg poisoning, obstructive uropathy, kidney failure.
May result from any serious damage to the kidneys or from a decrease in the flow of blood to the kidneys.
ANURIA
Increase in the nocturnal excretion of urine. Excretion of more than 500 mL urine at night with a specific gravity of less than 1.018.
If S.G. = 1.010, it is usually associated with impairment of tubular function or renal failure/necrosis.
NOCTURIA
“Transient polyuria;” may be due to the intake of substances with a diuretic effect, such as alcohol, coffee, or diuretic drugs
Transitory increase in urine volume
DIURESIS
A SMALL volume of urine is produced, as long as the diuretic substances are in one’s system.
TRUE OR FALSE
FALSE
A large volume of urine is produced by diuretic substances
PREFERRED SPECIMEN FOR URINE
First Morning
(most concentrated specimen of the day) collected using midstream clean-catch technique.
First Morning
The most common indication of routine urinalysis is?
the diagnosis of urinary tract infection (UTI).
One way to collect sterile urine suitable for bacterial culture, which will also be in conjunction with urinalysis
First Morning
Specimens must be collected in STERILE, dry, leakproof, and clear containers.
TRUE OR FALSE
FALSE
For first morning routine urinalysis CLEAN is enough
Disposable containers should be used because?
they eliminate the chance of contamination due to improper washing
Properly applied screw-top lids are less likely to leak than are snap-on lids.
TRUE OR FALSE
TRUE
Containers for routine urinalysis should have a NARROW mouth to facilitate collections from female patients and a wide, flat bottom to prevent overturning.
They should also be made of a IMPERMEABLE material to allow for determination of color and clarity.
TRUE OR FALSE
FALSE
Containers for routine urinalysis exhibit WIDE mouths and are made of CLEAR material
For routine urinalysis, we only need how much urine?
10 – 15 mL (avg. of 12 mL).
Containers must be large enough to allow room for mixing.
TRUE OR FALSE
TRUE
The recommended capacity of the container is 50 mL, which allows 12 mL of specimen needed for microscopic analysis, additional specimen for repeat analysis, and enough room for the specimen to be mixed by swirling the container.
used for microbiological studies of urine.
Individually packaged STERILE containers with secure closures
Labels must be attached to the LID of the container, not to the BODY, and should not become detached if the container is refrigerated or frozen.
TRUE OR FALSE
FALSE
Labels must be attached to the BODY
All specimens must be labeled immediately after collection
What are the minimum requirements for urine specimens?
o (1) Patient’s full name;
o (2) Date and time of collection;
o (3) Identification number (if present);
o (4) Additional information such as the patient’s age and location, the health care provider’s name, and the preservative used.
the form that must accompany specimens delivered to the laboratory.
Requisition Form
This form may include additional information such as method of collection or type of specimen, possible interfering medications, and the patient’s clinical information
The time the specimen is received in the laboratory should be recorded on the form. So that the staff will have a basis for determining the acceptability of the specimen
Requisition form
THE CRITERIA FOR URINE SPECIMEN REJECTION
- (1) Specimens in containers that are unlabeled or improperly labeled;
- (2) Labels and requisition forms that do not match;
- (3) Specimens contaminated with feces or toilet paper;
- (4) Containers with contaminated exteriors;
- (5) Specimens of insufficient quantity;
- (6) Specimens that have been transported improperly;
- (7) Specimens that have not been preserved correctly during a time delay
- (8) Specimens for urine culture collected in a nonsterile container;
- (9) Inappropriate collection for the type of testing needed (ex. midstream clean-catch specimen for bacterial culture).
After collection, specimens should be delivered to the laboratory promptly and tested within ___ hours
2hrs to preserve specimen integrity
A specimen that cannot be delivered and tested within 2 hours should be?
refrigerated or have an appropriate chemical preservative added.
Identify the analyte of changes in unpreserved urine
Oxidation or reduction of metabolites
Color
Modified/Darkened
Identify the analyte of changes in unpreserved urine
Bacterial growth and precipitation of amorphous material
Clarity
Decreased
Identify the analyte of changes in unpreserved urine
Bacterial multiplication causing breakdown of urea to ammonia
Odor
Increased ammonia smell
Identify the analyte of changes in unpreserved urine
Breakdown of urea to ammonia by urease-producing bacteria/loss of CO2.
pH
Increased
Identify the analyte of changes in unpreserved urine
Glycolysis and bacterial use.
Glucose
Decreased
Identify the analyte of changes in unpreserved urine
Volatilization and bacterial metabolism.
Ketones
Decreased
Identify the analyte of changes in unpreserved urine
Exposure to light/photo oxidation to biliverdin.
Bilirubin
Decreased
Identify the analyte of changes in unpreserved urine
Oxidation to urobilin.
Urobilinogen
Decreased
Identify the analyte of changes in unpreserved urine
Multiplication of nitrate-reducing bacteria
Nitrite
Increased
Identify the analyte of changes in unpreserved urine
Disintegration/lyse in dilute alkaline urine
Red and white blood cells and casts
Decreased
Identify the analyte of changes in unpreserved urine
Multiplication
Bacteria
Increased
Identify the analyte of changes in unpreserved urine
Loss of motility, death.
Trichomonas
Decreased
Most commonly used method of preservation; does not interfere with routine tests. Done at 2°C – 8°C which decreases bacterial growth and metabolism.
Refrigeration
If the urine is to be cultured, it should be refrigerated during transit and kept refrigerated until cultured, up to ___ hours
24hrs
If a technique prevents bacterial growth, the term “________” is used
“bacteriostatic”
Maintains an acid pH for up to 8 hours
REFRIGERATION
This is the disadvantage of what specimen preservation
Disadvantage: Can cause precipitation of amorphous urate and phosphate crystals, which would make the specimen turbid and increase its’ specific gravity
REFRIGERATION
When a specimen must be transported over a long distance and refrigeration is impossible, what is added as a substitute?
chemical preservatives may be added
The ideal specimen should be BACTERICIDAL, inhibit urease, and preserve formed elements in the sediment. The preservative should not interfere with chemical tests.
TRUE OR FALSE
TRUE
Urine preservative that does not interfere with chemical tests (Advantage)
Refrigeration
Urine preservative that precipitates amorphous phosphates and urates (Disadvantage)
Refrigeration
Urine preservative that prevents bacterial growth for 24 hours
Refrigeration
Urine preservative that prevents bacterial growth and metabolism. (advantage)
Acids (boric acid*, HCL, acetic acid, tartaric acid)
Urine preservative that Interferes with analysis of drugs and hormones (disadvantage)
Acids (boric acid*, HCL, acetic acid, tartaric acid)
Urine preservative that Keeps pH at about 6.0 (may be considered as a disadvantage; may interfere with pH reading); can be used for transport of urine cultures.
Acids (boric acid*, HCL, acetic acid, tartaric acid)
Urine preservative that is an Excellent sediment preservative (advantage)
Formalin (formaldehyde)
Urine preservative that Acts as a reducing agent, interfering with chemical tests for glucose, blood, leukocyte esterase, and copper reduction. (disadvantage)
Formalin (formaldehyde)
Urine preservative that is a Good preservative for drug analyses. (advantage)
Sodium fluoride
Urine preservative that Inhibits reagent strip tests for glucose, blood, and leukocytes (disadvantage)
Sodium fluoride
Urine preservative that is 50% alcohol and 2% carbowax 1540; prevents cell collapse.(advantage)
Saccomanno’s fixative (acellular/sediment preservative)
Urine preservative that May contain dehydrating agents. (disadvantage)
Saccomanno’s fixative (acellular/sediment preservative)
Urine preservative that is Commercially available preservative for cytology studies
Saccomanno’s fixative (acellular/sediment preservative)
Urine preservative that is Convenient when refrigeration not possible. Have controlled concentration to minimize interference (advantage)
Commercial preservative tablets
Urine preservative that Check tablet composition to determine possible effects on desired tests (disadvantage)
Commercial preservative tablets
Urine preservatives that Does not interfere with routine tests. (advantage)
PHENOL AND TOLUENE
Urine preservative that Causes odor change (disadvantage)
PHENOL
Urine preservative that Floats and clings to pipettes and other instruments.(disadvantage)
TOLUENE
Urine preservative that Acts as a physical barrier to air and bacteria.
TOLUENE
Urine preservative that Preserves glucose and sediments.(advantage)
Thymol
Urine preservative that Interferes with protein precipitation test (disadvantage)
Thymol
Urine preservative that is Effective against bacteria and molds.
Thymol
Contains collection cup, transfer straw, culture and sensitivity (C&S) preservative tube, or UA tube
URINE COLLECTION KITS (BECTON, DICKINSON, RUTHERFORD, NJ)
URINE COLLECTION KITS (BECTON, DICKINSON, RUTHERFORD, NJ)
Needle that mimics the vacutainer system in blood collection.
Transfer Device
Rinse specimen container with formalin to preserve cells and casts.
TRUE OR FALSE
TRUE
Identify this tube
- Culture and sensitivity.
- Preservative is boric acid, sodium borate, and sodium formate.
- Keeps pH at about 6.0.
Light Gray and Gray C&S Tube
Identify this tube
Use on automated instruments.
Yellow UA Plus Tube (Plain)
Identify this tube
- Preservative is sodium proprionate, ethyl paraben, and chlorhexidine.
- Round or conical bottoms.
Cherry Red/Yellow Preservatuve Plus Tube
This is an advantage of what tube?
Specimen is stable at room temperature (RT) for 48 hours; prevents bacterial growth and metabolism
Light Gray and Gray C&S Tube
This is an advantage of what tube?
Must refrigerate within 2 hours
Yellow UA Plus Tube (Plain)
This is an advantage of what tube?
Specimen stable at 72 hours at RT; instrument-compatible.
Cherry Red/Yellow Preservatuve Plus Tube
This is an disadvantage of what tube?
Do not use if urine is below minimum fill line.
Light Gray and Gray C&S Tube
This is an disadvantage of what tube?
Round or conical bottom; no preservative.
Yellow UA Plus Tube (Plain)
This is an disadvantage of what tube?
Must be filled to minimum fill line. Bilirubin and urobilinogen may be decreased if specimen is exposed to light and left at RT.
Cherry Red/Yellow Preservatuve Plus Tube
If the specimen stands for more than 2 hours and no preservative has been added, the color will change; usually LIGHTENS upon standing due to oxidation and reduction of metabolites.
TRUE OR FALSE
FALSE
The color DARKENS
The goal of preservation is either to prevent bacterial growth (bacteriostatic) or kill bacteria (bactericidal).
TRUE OR FALSE
TRUE
becomes alkaline; due to ammonia from the breakdown of urea by urease-producing bacteria
urine pH in unpreserved urine
These all increase in urine
Odor
pH
Nitrite (NO2)
Bacteria Crystals
These all decrease in urine
Clarity
Glucose
Ketones
Bilirubin
Urobilinogen
Cells and casts
T. Vaginalis
reduction of nitrate is done by?
nitrate-reducing bacteria.
decreased glucose is due to?
Glycolysis
Decreased ketones are due to?
due to volatilization or bacterial metabolism
Identify the type of specimen based on the given purpose
Routine screening
RANDOM
Identify the type of specimen based on the given purpose
Routine screening
Pregnancy tests
Orthostatic protein
FIRST MORNING
Identify the type of specimen based on the given purpose
Quantitative chemical tests
24-HOUR (OR TIMED)
Identify the type of specimen based on the given purpose
Bacterial culture
CATHETERIZED (sterile)
Identify the type of specimen based on the given purpose
Routine screening
Bacterial culture
MIDSTREAM CLEAN-CATCH
Identify the type of specimen based on the given purpose
Bladder urine for bacterial culture
Cytology
SUPRAPUBIC ASPIRATION
Identify the type of specimen based on the given purpose
Prostatic Infection
THREE-GLASS COLLECTION AND FOUR-GLASS COLLECTION
A RANDOM specimen can be accepted for analysis if it is not to DILUTE.
TRUE OR FALSE
TRUE
It must not be DILUTE, otherwise, it can lead to falsely low counts and concentrations of chemical components. It also may show erroneous results resulting from dietary intake or physical activity just before collection.
This is the specimen received most commonly because of its’ ease of collection and convenience for the patient. Can be collected at any time, but the actual time of voiding should be recorded on the container
Random Specimen
Preferred specimen for routine urinalysis, pregnancy testing, and for evaluating (orthostatic proteinuria)
FIRST MORNING SPECIMEN
a benign type of proteinuria, which is only due to the gravitational pull (that is, if you stand for 2 hours or so).
Orthostatic (Postural) Proteinuria
▪ Common among young adults; there is a significant excretion of protein in urine.
▪ This disappears once the patient assumes a recumbent or lying position.
▪ Results should be negative; otherwise, it indicates true proteinuria
Orthostatic (Postural) Proteinuria
The most concentrated specimen of the day; thereby, assuring detection of chemicals and formed elements that may not be present in a dilute random specimen.
FIRST MORNING SPECIMEN
Successive voidings within a specific period are combined in a single container
Rule: Begin and end the collection with an empty bladder. Then void or discard the first urine (time zero); should not be collected at the container.
24-HOUR (OR TIMED) SPECIMEN
When the concentration of the substance to be measured changes with DIURNAL VARIATIONS and with daily activities, such as exercise, meals, and body metabolism, 12-HOUR collection is required.
TRUE OR FALSE
FALSE
24-HOUR
Preferred specimen for clearance tests (tests used to estimate the glomerular filtration rate).
24-HOUR (OR TIMED) SPECIMEN
Addis count
- Sediments constituents are enumerated using a hemocytometer.
- Preservative: Formalin (excellent sediment preservative).
12-HOUR SPECIMEN
Urobilinogen is subjected to photooxidation; container must be protected from light (wrapped in aluminum foil or an amber container is used).
o Period of the day where urobilinogen concentration is at
its’ peak. (2:00 – 4:00).
2-HOUR SPECIMEN
SPECIMENS FOR DIABETIC SCREENING/MONITORING
- Second morning specimen (as to not get false positive results for glucose and ketones).
- The first morning specimen, after a period of fasting, must be discarded
o It is expected to contain food metabolites prior to the
beginning of period
FASTING SPECIMEN
SPECIMENS FOR DIABETIC SCREENING/MONITORING
- Best for detecting glucosuria (Renal threshold for glucose is exceeded or met)
2-H POST-PRANDIAL
SPECIMENS FOR DIABETIC SCREENING/MONITORING
Used to accompany blood specimen in a routine oral GTT (Glucose Tolerance Test).
GTT URINE
Renal threshold for glucose is exceeded or met.
glucosuria
is the most vulnerable part of a drug-testing program; requires the most stringent protocol due to the possibility of legal implications
Urine specimen collection
the process that provides this documentation of proper specimen identification from the time of collection to the receipt of laboratory results.
Chain of Custody (COC)
Urine specimen collections may be “witnessed” or “unwitnessed.”
TRUE OR FALSE
TRUE
Volume of urine observed by a same-gender collector under witnessed collection for a drug testing specimen
30 – 45 mL of urine;
Temperature range for urine drug testing specimen
32.5°C to 37.7°C.
The urine temperature must be taken within 4 minutes from the time of collection to confirm the specimen has not been adulterated.
A specific gravity of less than 1.005 could indicate dilution of the urine specimen and requires re-collection for drug testing specimens.
TRUE OR FALSE
TRUE
This technique provides a safer, less traumatic method for obtaining urine for bacterial culture and routine analysis.
MIDSTREAM CLEAN-CATCH TECHNIQUE
Patients must be provided with appropriate cleansing materials, a sterile container, and instructions for cleansing and voiding in what collection technique
MIDSTREAM CLEAN-CATCH TECHNIQUE
Strong bacterial agents, such as hexachlorophene or povidone-iodine, should NOT be used as cleansing agents in performing MIDSTREAM CLEAN-CATCH TECHNIQUE
TRUE OR FALSE
TRUE
Mild antiseptic towelettes are recommended.
Collected under STERILE conditions by passing a hollow tube (catheter) through the urethra into the bladder
CATHETERIZATION
Occasionally, urine may be collected by external introduction of a needle through the abdomen into the bladder; traumatic procedure
SUPRAPUBIC ASPIRATION
the bladder is STERILE under normal conditions, this provides a specimen for bacterial culture that is completely free of extraneous contamination, particularly in infants or children. The specimen also can be used for cytology studies.
TRUE OR FALSE
TRUE
In 3 glass collection WBC and bacterial counts in tube 3 is 10x of those of tube 1.
TRUE OR FALSE
TRUE
Also known as the (FOUR-GLASS TECHNIQUE)
STAMEY-MEARES TEST
These are observed in what specimen collection?
- Soft, clear plastic bags are available for collecting routine specimens.
o These bags have hypoallergenic skin adhesive to attach to the cleaned genital area of both boys and girls.
o Sterile specimens may be obtained by catheterization or by suprapubic aspiratio
PEDIATRIC SPECIMEN COLLECTION
