Urinalysis Flashcards
What are the clinical reasons for performing urinalysis testing?
An important indicator of health, a screening test to detect and assess: Renal funciton, endocrine or metabolic function disorder, urinary tract infection and systemic diseases.
What are the methods of urine collection?
First morning void
Random urine
Clean catch
24-hour specimen
What are the methods of instrumented collection?
Urethral catheterization
Suprapubic needle aspiration
catheterization and bladder irrigation
How soon should urine specimens be analyzed while fresh?
1-2 hours
refrigerate the specimen 3-6 hrs after
What do urea splitting bacteria produce?
Ammonia, which then combines with hydrogen ions to increase ph of teh urine. Changes in pH will dissolve any casts present. If glucose is present, the bacteria may use it as a source of energy resulting in false negative glycosuria.
What urinary elements will deteriorate if left standing without any kind of preservative?
Blood Cells and casts
What is the advantage and disadvantage of freezing?
A: no cost, simple to perform
D: May destroy formed elements
What is the advantage and disadvantage of toluene?
A: Preserves acetone, diacetic acid and proteins by floating on top of urine
D: Flammable, difficult to separate from specimen.
What is the advantage and disadvantage of thymol?
A: Inhibits bacteria/fungus
D: False positive for protein
What is the advantage and disadvantage of chloroform?
A: Preserves urine aldosterone levels
D: Settles to bottom of containers
What is the advantage and disadvantage of formaldehyde?
A: Preserves urinary sediment/ cells
D: Interferes with glucose evaluation.
What is the advantage of hydrogen chloride?
A: Stabilizes steroids
D: Hazardous liquid and fumes, formed elements are destroyed.
What are the advantages and disadvantages of boric acid?
A: Preserves chemical and formed elements
D: Uric Acid may precipitate.
What are the advantages and disadvantages of preservation tablet?
A; Preserves urine for dipstick chemical analysis and sediment evaluation.
D: Unsuitable for sodium, potassium, and hormone analysis.
What is the diagnostic use of first morning void?
most concentrated, increased number of abnormal elements, decreased deterioration of formed elements, recommended specimen for chemical and microscopic examination.
What is the diagnostic use of random urine specimen?
Collected anytime, most convenient and most common, can detect abnormalitites but not as sensistive as first morning void
What is the diagnostic use clean catch?
specimen of choice for bacterial cultures. may perform cultures within 12 hours after collection if specimen was refrigerated. genitalia must be cleaned with mild antiseptic solution.
What is the diagnostic use of 24 hour specimen?
gives quantitative results and preservatives may be needed
What is the diagnostic use of urethral catheterization?
not recommended for bacteriologic examination, use only if no other way to collect urine, commonly used on marked obese patient with difficulty in urine collection