Urinalysis Flashcards
1
Q
Types of common urine specimens
A
Random, first morning, midstream clean catch, catheterized, 24-hour (timed), drug screening.
2
Q
first morning urine is for
A
confirmatory test for orthostatic proteinuria and pregnancy.
3
Q
for bacterial cultures
A
midstream clean catch and catheterized
4
Q
provide quantitative results
A
24 hour (timed) urine
5
Q
strictly follow chain-of-custody form requirements
A
Drug screening
6
Q
Test specimens within
A
2 hours of collection
7
Q
_____________ specimens that cannot be tested within 2 hours
A
Refrigerate
8
Q
increased results in unpreserved urine
A
pH, nitrite, bacteria
9
Q
decreased results in unpreserved urine
A
Glucose - glycolysis,
Ketones - Oxidation,
Bilirubin - Oxidation to biliverdin,
Urobilinogen - oxidation to urobilin.
10
Q
normal urine volume
A
600 to 2000 mL/day
11
Q
decreased urine output
A
oliguria, less than 400mL/day
12
Q
no urine output
A
anuria
13
Q
increased urine output at night
A
nocturia
14
Q
increased urine output
A
polyuria, greater than 2500 mL/day
15
Q
increased urine output to excrete excess urine glucose is seen in
A
Diabetes mellitus
16
Q
increased urine output caused by lack or dysfunction of antidiuretic hormone (ADH) is seen in
A
Diabetes insipidus
17
Q
polyuria results in
A
polydipsia
18
Q
normal urine color is
A
yellow
19
Q
Seen in refrigerated normal urine
A
White turbidity - urine with alkaline pH from amorphous phosphates and carbonates.
Pink rabidity - urine with an acid pH from amorphous urates.
20
Q
Nonpathologic turbidity
A
squamous epithelial cells, mucus, amorphous phosphates,carbonates, and urates, semen, feces, radiographic contrast edia, powder and creams.
21
Q
Pathologic turbidity
A
RBCs, WBCs, yeast, urothelial and renal tubular epithelial cells, abnormal crustals, lipids (milky).
22
Q
Specific gravity is a
A
screening test for reneal tubular reabsorption of essential elements filtered by the glomerulus
23
Q
specific gravity is based on the fact that glomerular filtrate ha a specific gravity of
A
1.010
24
Q
urine contains dissolved substances that produce density by their
A
size and number
25
principle of sp. gr. in reagent strip
based on the number of hydrogen ions released from a polyelectrolyte (pKa) is proportional to the number of ions in the urine.
increased urine concentration = increased hydrogen ions released = low pH
the indicator on the strip is bromothymol blue
reaction - yellow-green (acid) - green-blue (alkaline)
26
principle of refractometer
the concentration of dissolved particles in a solution determines the velocity and angle of light passing through a solution.
the refractometer uses a prism to direct a wavelength of light through the urine, the angle of the light can be read on a scale calibrated with distilled water.
27
considered more representative of renal concentrating ability than specific gravity
osmolarity, because it measures only the number of particles and their size is not relevant.
measurement is the number of particles into which 1gram MW of a substance dissociates.
ex: Nonionizing urea (MW 60) = 1 particle, ionizing NaCl (MW 58.5) = 2 particles.
reported in milliosmoles (mOsm)
28
Colligative properties measured in the clinical laboratory
freezing point depression and vapor pressure depression.
29
describe freezing point depression
one mole of nonionizing substance will lower the freezing point 1.86 oC.
Volatile substances such as alcohol can interfere.
30
Describe vapor pressure depression
Actual measurement is the dew point (temperature at which vapor condenses to a liquid) of the urine sample.
Uses microsamples on filter paper discs. Care must be taken to avoid evaporation.
No interference from volatile substances.
31
Normal serum osmolarity
275 t0 300 mOsm
32
urine osmolality is influenced by
fluid intake
33
random serum-to-urine osmolarity ratio is
1:1
34
controlled fluid intake should reach
1:3
35
Osmolarity is used to
determine ADH production or tubular response to ADH for diabetes insipidus.
uses harmonic oscillation density?
36
automated instrumentation principle on osmolarity
it passes a sound wave through the urine and records the change in frequency of the sound wave, which is proportional to the urine density
37
briefly dip reagent strips to prevent
leaching or reagents from strip
38
thoroughly mix specimens for
detection of RBCs and WBCs
39
warm refrigerated specimens for
enzyme reactions
40
blot strip while removing from urine to
prevent runover
41
observe manufacturer timing instructions in
reaction color changes
42
the pH of fresh urine does not reach
9.0.
| a reading of 9.0 indicates an old specimen that should be recollected.
43
urine pH normal value
4.5 to 8.0
44
pH reagent strip principle
double indicator (methyl red and bromothymol blue)
45
clinical significance of urine pH
detection of systemic acid-base disorders.
| identification of urinary crystals.
46
reagent strips measure primarily what protein
albumin
47
urine protein NV is
10 mg/dL
48
considered clinical proteinuria
30 mg/dL or greater
49
reagent strip principle for protein
the protein error of indicators
50
clinical significance of urine protein
clinically significant proteinuria is primarily caused by glomerular or tubular disorders.
Benign orthostatic proteinuria testing requires a first morning and a specimen after the patient has been active for 2 hours. The first specimen should be negative and the second specimen positive.
51
requires a different reagent strip capable of testing for only albumin at levels below 10mg/dL
microalbumin
52
microalbumin is used to
provide early detection of renal disease, particularly in patients with diabetes.
53
The __________ tests for microalbumin and creatinine, along with all other routine strip tests, except urobilinogen
Multistix PRO 11 reagent strip
54
_______ corrects for hydration in a random sample to provide an estimate of the 24-hour microalbumin level
Albumin-to-creatinine ratio.
55
glucose reagent strip principle
Glucose oxidase test (specific for glucose)
56
the renal threshold for glucose is
160 to 180 mg/dL
57
urine glucose clinical significance
Diabetes mellitus, gestational diabetes (placental hormones blocking insulin)
Hormonal disorders and stress block insulin production and actions.
Renal tubular disorders prevent tubular reabsorption of glucose.
58
Clinitest principle
reducing substances including glucose and other sugars can reduce copper sulfate (blue-green) to cuprous oxide (orange-red)
59
clinitest can be used in
testing newborn urine for galactose
*high levels will pass through the reaction and go from blue-green to orange-red to blue-green. carefully observe the reaction.
60
ketones are
intermediate metabolites of fat:
| acetoacetic acid, acetone, and B-hydroxybutyric acid.
61
urine ketone principle
reaction of acetoacetic acid or acetone (with glycine) with sodium nitroprusside/ferricynade
62
urine ketone clinical significance
Diabetes mellitus, monitoring of insulin therapy, starvation, malabsorption, and loss of carbohydrate (vomiting)
63
urine blood positive reactions are ssen with
hematuria, hemoglobinuria, and myoglobinuria
64
urine blood principle
pseudoperoxidase activity of hemoglobin
65
urine blood CS
both hemoglobinuria and myoglobinuria can cuase acute renal failure.
Hematuria - bleeding within the genitourinary system, including renal calculi, trauma, anticoagulants, glomerulonephritis, and pyelonephritis.
hemoglobinuria - intravascular hemolysis/ transfusion reactions, lysis of old RBCs by dilute alkaline urine.
Myoglobinuria - Rhabdomyolysis caused by muscle-wating disorders, crush injuries, prolonged coma, and cholesterol statin drugs.
66
products of hemoglobin degradation
bilirubin and urobilinogen
67
urine bilirubin principle
diazo reaction
68
urine bilirubin CS
conjugated bilirubin enters the urine as a result of leakage from a damaged liver or blocked bile duct.
The kidneys cannot filter unconjugated bilirubin.
Patients will appear jaundiced.
69
Some of the conjugated bilirubin is coverted to _______________ in the intestine
urobilinogen.
| Then it circulates in the blood to the liver and passes through the kidneys.
70
normal urobilinogen in urine
1 mg/dL
71
urine urobilinogen principle
multistix - Ehrlich's reaction.
| chemstrip - diazo reaction.
72
urine urobilinogen CS
early detection of liver disease and hemolytic disorders, constipation.
73
urine nitrite detects
the presence of reductase-producing bacteria that can convert urinary nitrate to nitrite.
74
urine nitrite principle
diazo reaction
75
urine nitrite CS
early detection of urinary tract infection.
a positive nitrite test should be accompanied by a positive leukocyte esterase test.
may be used to screen specimens for microbiology testing.
76
leukocyte esterase detects
the presence of granulocytic WBCs, including lysed WBCs.
77
urine leukocyte esterase principle
Diazo reaction: the leukocyte esterase reagent strip reaction should be read 2 minutes after urine exposure.
78
urine leukocyte esterase CS
UTI, including with non-reductase-containing bacteria and parasitic and fungal organisms that would have a negative nitrite test.
79
casts are composed of what protein
Tamm-Horsfall (uromodulin) protein excreted by renal tubular epithelial cells
80
casts are formed in the
distal convoluted tubule and collecting ducts (wider casts)
81
casts are reported as
number per low-power field
82
RBCs appear _____ in concentrated urine
crenated
83
RBCs appear _________ in dilute urine
larger empty cells (ghost cells)
84
______________ indicate glomerular bleeding
regular (dysmorphic) shapes)
85
RBCs sources of error
oil droplets, air bubbles, yeast cells (look for budding)
86
Urine RBCs clinical significance
glomerular membrane damage,
Blleding in the urinary tract,
renal calculi,
malignancy
87
hemoglobinuria or myoglobinuria is indicated by
a clear red urine with a positive reagent strip RBC and no RBCs in the microscopic analysis
88
Eosinophils have red granules when stained with
Wright or Hansel stains
89
neutrophils that have swollen in dilute urine, resulting in Brownian movement of the granules in the cytoplasm
Glitter cells
90
describe glitter cells
neutrophils that have swollen in dilute urine, resulting in Brownian movement of the granules in the cytoplasm
91
WBCs sources of error
renal tubular epithelial cells, mononuclear lymphocytes, and monocytes
92
WBC urinalysis correlations
leukocyte esterase, nitrite, pH, and specific gravity (glitter cells)
93
WBCs CS
UTI (neutrophils),
Drug-induced interstitial nephritis (eosinophils),
malignancy (mononuclear cells)
94
largest cells in the urine sediment
Squamous cells.
-represent normal sloughing of old lower genitourinary tract cells.
*folded squamous cells may resemble urinary casts (look for a centrally located nucleus)
95
squamous epithelial cells covered with Gardnerella vaginalis bacteria, indicating a vaginal infection
Clue cells
96
Describe clue cells
squamous epithelial cells covered with Gardnerella vaginalis bacteria, indicating a vaginal infection
97
Transitional (urothelial) cells are found in
renal pelvis, ureters, bladder and male urethra.
normally seen after catheterization procedures (often seen in clumps)
98
forms of transitional cells
spherical, caudate, and polyhedral.
Spherical cells resemble renal tubular cells, except they have a centrally located nucleus.
99
increased transitional cells may indicate
malignancy
100
Renal tubular epithelial cells are found in
renal tubules and collecting duct.
cell shape vary with location.
Convoluted tubule cells are rectangular with coarse granules and may resemble a cast (look for a nucleus)
Distal convoluted tubule cells are small and round, may resemble spherical transitional cells buth have an eccentric nucleus.
Cells from collecting duct are cuboidal with at least one straight edge ad are frequently seen in clumps.
101
Renal Tubular Epithelial cells (RTE) CS
more than two RTE cells per HPF is significant.
Tubular necrosis, often from poisoning or viral infections.
RTE cells absorb filtrate and may be bilirubin stained (liver damage), contain hemosiderin granules (hemoglobin) or lipids.
102
RTE cells that have absorbed lipids
Oval fat bodies
103
describe oval fat bodies
RTE cells that have absorbed lipids.
highly refractile.
Seen in conjunction with free-floating lipids.
confirm staining with oil red O, Sudan III, or polarized microscopy.
104
oval fat bodies CS
Nephrotic syndrome, diabetes mellitus, and crush injuries.
105
bacteria should be accompanied by
WBCs
106
bacteria sources of error
amorphous urates, phosphates, and old specimens with a high pH
107
bacteria CS
UTI
108
oval structures with buds or mycelia
yeast
109
describe yeast
oval structures with buds or mycelia
110
yeast should be accompanied by
WBCs
111
Yeast is associated with
acidic urine from patients with diabetes mellitus
112
yeast source of error
RBCs
113
yeast CS
DM, immunocompromised patients, vaginal infections
114
parasites in urine
Trichomonas vaginalis, Schistosoma haematobium, Enterobius vermicularis (fecal contamination)
115
describe Trichomonas vaginalis
exhibits rapid flagellar movement in wet preparations
116
urine parasites source of error
WBCs and renal tubular epithelial cells
117
urine parasites CS
sexually transmitted disease that is asymptomatic in males and causes a vaginal infection in females
118
strands of protein secreted by glands and renal tubular epithelial cells
Mucus
119
describe mucus
strands of protein secreted by glands and renal tubular epithelial cells
120
major protein of mucus
Tamm-Horsfall (uromodulin) protein
121
Mucus sources of error
clumps may resemble hyaline casts (look for the consistent shape of a cast)
122
Mucus CS
Mucus is of no clinical significance
123
precipitation of urine solutes affected by temperature, solute concentration, and pH
Crystals
124
describe crystals
precipitation of urine solutes affected by temperature, solute concentration, and pH
more abundant in refrigerated specimens.
polarized microscopy aids in their identification
abnormal crystals are found only in acidic or normal urine.
125
normal crystals seen in acidic urine
Uric acid crystals, amorphous urates, calcium oxalate
126
normal crystals seen in alkaline urin
triple phosphate crystals, amorphous phosphate crystals, calcium carbonate crystals, ammonium biurate crystals
127
abnormal crystals
cysteine, cholesterol, tyrosine, leucine, bilirubin, sulfonamide, ampicillin
128
yellow-brown, flat sided rhombic plates, wedges, and rosettes
uric acid crystals
129
describe uric acid crystals
yellow-brown, flat sided rhombic plates, wedges, and rosettes
130
uric acid crystals SOE
cysteine crystals (uric acid crystals polarize and cysteine crystals do not polarize)
131
uric acid crystals CS
patients receiving chemotherapy, Lesch-Nyhan disease
132
small spheres producing brick-dust (uroerythrin) or yellow-brown sediment
amorphous urates
133
describe amorphous urates
small spheres producing brick-dust (uroerythrin) or yellow-brown sediment
134
describe calcium oxalate crystals
may also be seen in alkaline urine
The dehydrate form is envelope shaped; clumps in fresh urine may indicate renal calculi.
The monohydrate form is oval or dumbbell shaped; presence of this form indicates ethylene glycol (anti-freeze) ingestion
135
coffin-lid shaped
triple phosphate crystals
136
describe triple phosphate crystals
coffin-lid shaped
associated with a very high pH and bacteria found in old specimens
137
produce a white precipitate after refrigeration
amorphous phosphate crystals
138
dumbbell and spherical shapes. produce gas with acetic acid
Calcium carbonate crystals
139
describe calcium carbonate
dumbbell and spherical shapes. produce gas with acetic acid
140
yellow-brown thorny apple-shaped crystals.
ammonium biurate crystals
141
describe ammonium biurate crystals
yellow-brown thorny apple-shaped crystals.
| associated with old specimens with bacteria.
142
hexagonal flat plates
cystine crystals
143
describe cystine crystals
hexagonal flat plates.
an inherited disorder that inhibits the reabsorption of cystine by the renal tubules (cystinuria); renal calculi form at an early age
144
rectangular plates with notched corners, highly birefringent under polarized light
cholesterol crystals
145
describe cholesterol crystals
rectangular plates with notched corners, highly birefringent under polarized light.
seen in refrigerated urine and accompanied by fatty casts and oval fat bodies.
Nephrotic syndrome.
146
yellow needle-shaped forms in clusters or rosettes
tyrosine crystals
147
describe tyrosine crystals
yellow needle-shaped forms in clusters or rosettes.
| Severe liver disease.
148
yellow-brown spheres with concentric circles
Leucine crystals
149
describe leucine cystals
yellow-brown spheres with concentric circles.
seen in conjunction with tyrosine crystals. seen in sever liver disease.
150
bright yellow clumped needles and granules
bilirubin crystals
151
describe bilirubin crystals
bright yellow clumped needles and granules.
liver damage often from viral infections that damage the renal tubules, preventing reabsorption of bilirubin
152
needle, rosette, and rhombic shapes
sulfonamide crystals
153
describe sulfonamide crystals
needle, rosette, and rhombic shapes.
inadequately hydrated patients taking sulfonamide medications.
154
colorless needles that form clumps after refrigeration
ampicillin crystals
155
describe ampicillin crystals
colorless needles that form clumps after refrigeration.
inadequately hydrated patients taking ampicillin
