Urine Chemical Exam Flashcards
briefly dip reagent strips to prevent
leaching or reagents from strip
thoroughly mix specimens for
detection of RBCs and WBCs
warm refrigerated specimens for
enzyme reactions
blot strip while removing from urine to
prevent runover
observe manufacturer timing instructions in
reaction color changes
the pH of fresh urine does not reach
9.0.a reading of 9.0 indicates an old specimen that should be recollected.
urine pH normal value
4.5 to 8.0
pH reagent strip principle
double indicator (methyl red and bromothymol blue)
clinical significance of urine pH
detection of systemic acid-base disorders.identification of urinary crystals.
reagent strips measure primarily what protein
albumin
urine protein NV is
10 mg/dL
considered clinical proteinuria
30 mg/dL or greater
reagent strip principle for protein
the protein error of indicators
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.
requires a different reagent strip capable of testing for only albumin at levels below 10mg/dL
microalbumin
microalbumin is used to
provide early detection of renal disease, particularly in patients with diabetes.
The __________ tests for microalbumin and creatinine, along with all other routine strip tests, except urobilinogen
Multistix PRO 11 reagent strip
_______ corrects for hydration in a random sample to provide an estimate of the 24-hour microalbumin level
Albumin-to-creatinine ratio.
glucose reagent strip principle
Glucose oxidase test (specific for glucose)
the renal threshold for glucose is
160 to 180 mg/dL
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.
Clinitest principle
reducing substances including glucose and other sugars can reduce copper sulfate (blue-green) to cuprous oxide (orange-red)
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.
ketones are
intermediate metabolites of fat:acetoacetic acid, acetone, and B-hydroxybutyric acid.
urine ketone principle
reaction of acetoacetic acid or acetone (with glycine) with sodium nitroprusside/ferricynade
urine ketone clinical significance
Diabetes mellitus, monitoring of insulin therapy, starvation, malabsorption, and loss of carbohydrate (vomiting)
urine blood positive reactions are ssen with
hematuria, hemoglobinuria, and myoglobinuria
urine blood principle
pseudoperoxidase activity of hemoglobin
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.
products of hemoglobin degradation
bilirubin and urobilinogen
urine bilirubin principle
diazo reaction
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.
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.
normal urobilinogen in urine
1 mg/dL
urine urobilinogen principle
multistix - Ehrlich’s reaction.chemstrip - diazo reaction.
urine urobilinogen CS
early detection of liver disease and hemolytic disorders, constipation.
urine nitrite detects
the presence of reductase-producing bacteria that can convert urinary nitrate to nitrite.
urine nitrite principle
diazo reaction
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.
leukocyte esterase detects
the presence of granulocytic WBCs, including lysed WBCs.
urine leukocyte esterase principle
Diazo reaction: the leukocyte esterase reagent strip reaction should be read 2 minutes after urine exposure.
urine leukocyte esterase CS
UTI, including with non-reductase-containing bacteria and parasitic and fungal organisms that would have a negative nitrite test.