Urinalysis Flashcards
What is urinalysis?
Why do it?
Screening/diagnostic tool for detection of urinary substances or cellular material associated with various disorders
Reveal asymptomatic diseases & confirm clinically suspected diagnoses
What are the types of urine collection & what is the most common?
- Random/spot urine (most common)
- clean catch
- clean the genitals
- catheterized
- in & out catheter to get a cleaner sample
- suprapubic
- across the skin above the pubic bone & into bladder
- mostly done w/ children
- first morning
- if you are looking for certain metabolites or looking for mycobacteria (tuberculosis)
- 24-hr urine
How quickly should you test the urine specimen?
What should you do to the specimen just prior to testing?
test as soon as possible
mix the urine just before testing
What is the very first thing you do when performign a urinalysis?
- Visual inspection
- Normal: clear to slightly hazy, pale yellow
- Cloudy urine from crystals or urinary tracty infection
- often crystal will precipitate out at room temperature
What are common causes for cloudy urine?
- Crystals
- Cells
- leukocytes
- RBC
- Microorganisms
- sperm
- mucin
- fecal contamination
- radiographic dye
What are common causes for milky urine?
- many neutrophils (pyuria) – pus
- lipiduria (nephrosis, crush injury)
- chyluria (lympatic obstruction)
- emulsified paraffin (vaginal creams)
Pink, red, or red-brown urine could indicate the presence of what substances in the urine?
blood, hemoglobin, or myoglobin
Yellow-brown or green-brown urine could indicate the presence of what substances in the urine?
bile pigments (mainly bilirubin), may foam when shaken
Orange-red or orange-brown urine could indicate the presence of what substances in the urine?
urobilinogen
b/c urobilinogen is converted urobilin in presence of light
Dark brown-black urine could indicate the presence of what substances in the urine?
methemoglobin, homogentisic acid, or melanin
What is the second step in performing a urinalysis?
Urine dipstick (reagent test strip)
can test a whole bunch of things at once & results are available within minutes
Urine dipstick test for the presenc of what substances?
- leukocytes
- nitrites
- pH
- protein
- glucose
- ketones
- urobilinogen
- bilirubin
- blood
- specific gravity
What are normal findings for specific gravity on urinalysis?
1.016 to 1.022 in healthy adults
What are normal findings for pH on urinalysis?
4.6 - 8.0 ave ~6
What are the normal “negatives” on the dipstick?
- glucose
- ketones
- blood, hemoglobin, hemosiderin & myoglobin
- protein
- bilirubin
- urobilinogen
- nitrites
- leukocyte esterase
What is the third step to a urinalysis?
microscopic examination if necessary
During a microscopic evaluation, urine sediment is searched for what substances?
- cells
- casts
- crystals
- organisms
Why would you see ketones in someones urine?
defects in carbohydrate metabolism
diabetic ketoacidosis
or are starving
What parameters indicate an abnormal RBC finiding in microscopic examination of urine?
This is indicative of what type of problem?
- Normal: 0-2/ High power field (HPF)
- >3/HPF = abnormal
- Increased in
- renal disease
- lower urinary tract diseases
- extrarenal diseases
- physiologic causes (exercise)
What are normal parameters for concentration fo white blood cells in urine microscopic analysis? Abnormal?
This is increased in what conditions?
- Normal: 3-5/HPF
- Pyuria
- increased urine neutrophils
What type of cells are these?
Why would you look for them in the urine?
Squamous/Transitional epithelium
Renal tubular epithelial cells (from kidney- increased # = tubular damage)
they are coming from the urinary tract & you can deciphere where in the tract they are coming from
What are casts?
What is a special consideration when searching for casts?
matrix of protein that is produced in the renal-tubular epithelium
can be normal or pathologic
they tend to degenerate as the urine ages
What is shown in the provided image?
Hyaline Casts
take on the shape of the tubule in which they were formed
cylindrical, blunted ends
What is shown in the provided images?
What conditions cause each of these structures?
Left = WBC cast (inflammatory/infectious conditions)
Right = RBC cast (prolonged urine stasis- obstruction & any type of glomerular injury)
What is shown in the provided images?
What conditions cause each of these structures?
Left = Granular cast (glomerulus)
Right = Waxy cast (have more rectangular ends than hyaline casts & might have little cracks- chronic renal failure)
What crystal is shown in the provided image?
these are typically seen at what pH?
Are they pathologic or no?
amorphous urates
small yellow-brown granules
amorphous & will not be uniform
typically seen at low pH (~5)
non-pathologic
What crystal is shown in the provided image?
Typically seen at what pH?
Are they pathologic or no?
Uric Acid
Barrel-shaped, plate-like or diamoned-shaped, orange-brown or yellow color
& sometimes stack on each other
Low pH (~5)
Considered non-patholgic, but they can also be seen in urate nephropathy & gout
What crystal is shown in the provided image?
What pH do these occur?
Are they pathological?
Calcium Oxalates
small, colorless octahedron- resemble an envelope
dumbell shapes & ovoid forms may occur
Acidic urine
Non-pathologic; but can see huge numbers in peopel who ingest ethylene glycol (antifreeze)
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Amorphous phosphates
similar to amorpohous urates, but are in alkaline urine
yellow-brown color
Non-pathologic
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Calcium Phosphates
“pointed fingers” and “pen nibs”
flat & elongated; stack up & clump together
occur in alkaline urine
non-pathologic
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Triple Phosphates (ammonium magnesium phosphates)
colorless, 3-6 sided prism “coffin lids”
may form sheets or flakes
alkaline urine
non-pathologic
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Ammonium biurates
yellow-brown spheres with radial or concentric striations
irregular projections or thorns (thornapple)
alkaline urine
non-pathologic
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Calcium carbonate
clumps & dumbbells
alkaline
non-pathologic
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Cystine
colorless, refractile, hexagonal plates
acidic urine
pathologic: cystinuria (inherited metabolic disease)
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Tyrosine
Silky needles arranged in sheaves of clumps
acidic to neutral urine
Pathologic: liver disease & tyrosinemia (inherited metabolic disease)
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Leucine
yellow, oily appearing spheres
radial and concentril striations
acidic to neutral pH
pathologic: liver disease
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Cholesterol
plates with notched corners
acidic to neutral pH
Pathologic: nephrotic syndrome
What crystal is shown in the provided image?
What pH do they occur?
Are they pathological?
Bilirubin
Clumps of brown needles
acidic to neutral pH
pathologic: liver disease
What structure is indicated by the black arrows?
Bacterial- gram (-) rods
What structure is indicated by the provided photo?
Budding yeast
common contaminants
seen in urinary tract infection- especially in diabetics, has a catheter, or is immunosuppressed
What structure is indicated by the provided photo?
Trichomonas Vaginalis
protazoan parasite w/ flagella
vaginal contaminant
but, can hav einfection of the uretha or bladder
