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UMG/UDL Point of Care Policy
D:\493712447.doc
6/28/2017
University
Diagnostic
Laboratories
POCT Program
PROCEDURE
Procedure: Microscopic Examination of Urine
Prepared by
Evan Cadoff, M.D.
Revision Date
6/8/99
10/10/01
Date Adopted
7/7/97
Supersedes Procedure #
Revision summary
Updated procedure to Word format.
Remove references to outpatient services.
Added lot to lot verification requirement
Update formatting
Review Date
Revision Date
Signature
# of Copies
Distributed to
UDL POCT sites
Distributed to
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Copies
1
PRINCIPLE
Analysis of urine may be used for either one of two purposes. One is to determine the
presence of body disturbances, such as endocrine or metabolic abnormality in which the
kidneys function normally and excrete abnormal amounts of metabolic end products
specific for a particular disorder. The second purpose is to detect intrinsic conditions that
may affect the kidneys or urinary tract. Diseased kidneys cannot function normally in
regulating the volume and composition of body fluids and maintain homeostasis.
Therefore, substances normally retained by the kidneys or excreted in small amounts
may appear in the urine in large quantities and substances normally excreted may be
retained. Structural elements, such as red blood cells, cells from the urinary tract,
leukocytes, bacteria, and casts from the impaired kidneys or lower urinary tract may
appear in the urine.
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SPECIMEN COLLECTION
The optimal container for collecting urine is the plastic screw top cup. For patients
bringing specimens collected at home, small glass jars with screw caps (i.e. baby food
jars), are acceptable but must be well cleansed and thoroughly dried before the specimen
is collected. Other containers are not acceptable.
Specimens from infants and young children may be collected in a disposable collection
apparatus consisting of a plastic bag with an adhesive backing around the opening to
fasten it to the child allowing the specimen to be voided directly into the bag. After
removal, the top of the bag is rolled down to close and then placed into a plastic screw top
urine container to be transported to the laboratory.
The procedure most commonly used for obtaining urine for urinalysis along with
bacteriologic examination and culture is the clean catch or midstream specimen. To
avoid contamination of the voided specimen by organisms in areas adjacent to the
urethral meatus, this area must be cleansed thoroughly before the patient voids. To avoid
contamination of the specimen with organisms normally located in the distal urethra, the
initial stream of voided urine which clears these organisms from the urethra is discarded
and the subsequent midstream urine is collected. A description of the optimal technique
for the clean catch urine collection can be found as an addendum to this procedure.
Bladder catheterization and percutaneous suprapubic aspiration of the bladder may be
used, but only in rare and unusual circumstances.
Most testing is done on a random specimen of urine, freshly voided by the patient,
although a first morning specimen is preferable. The specimen is collected in a clean, dry
container and should be examined within one hour as to avoid changes or deterioration in
the urine. If the specimen is to be kept more than one hour before the analysis, it should
be refrigerated at 2 - 8oC and returned to room temperature before analysis. All
collection containers and testing vessels should be free of any disinfectants or detergents.
Specimens must be labeled with the patient’s name. The container should be labelled in
advance, or the patient should be provided with a means of labelling the sample (ie, a pen
or pencil available in the bathroom).
At least 10 ml. of urine is required for an optimal evaluation. If less than 5 ml is received,
a microscopic evaluation should not be performed.
REAGENTS AND EQUIPMENT
Centrifuge Tubes
Plain Glass Slides
Cover Slips, 22x22 mm
Timer
Centrifuge
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URINALYSIS PROCEDURE
Centrifuged urinary sediment is examined microscopically first under the 10X
objective to tabulate casts and get an overview of the sediment. Then changed to
the 40X objective to tabulate the cellular elements and to identify any crystals
seen.
URINE MICROSCOPIC PROCEDURE
1. Ascertain that a microscopic examination is necessary based on your
findings during the chemistry phase of the urinalysis.
2. Transfer 10 ml. of urine to a labeled conical urine centrifuge tube.
3. Centrifuge the tube for five minutes at 2400 RPM. A longer duration or
faster speed will result in the cellular elements being damaged making
identification difficult.
4. Decant the supernatant and resuspend the sediment by gently vortexing
the tube with your finger.
5. Place a drop of the resuspended sediment on a clean slide, and coverslip
with a 22x22 mm coverglass.
6. Observe and tabulate your findings of 10 fields each at 10X and 40X
power.
REPORTING RESULTS:
Record your findings in the patients record. Record in the patient log the
information required.
Since testing is physician performed, further reporting of results or
documentation is not necessary.
LIMITATIONS
Despite care in specimen collection, various artifacts and contaminants may
occasionally be found in a sample, such as talcum powder, starch particles,
Vaseline, glass particles, clothing fibers, etc. Careful examination is required to
correctly identify the artifact. If necessary, a repeat specimen may be required.
REFERENCES
Haber, Meryl H., M.D., Primer of Microscopic Urinalysis, Fountain Valley, Ca.:
Scientific; 1978
ICL
Ames Co., Div. Miles Laboratories, Inc., Modern Urinalysis, Chicago, III.: Stern's Printers; 1974
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