Urinalysis Chapter 5

Liver damage Urine bilirubin results: Urobilinogen results:

+ or - positive (+ +: 2+)

In glomerular proteinuria, abnormal substances deposit on the membrane and can cause immune disorders such as what 2:

-Lupus erythematosus -streptococcal glomerulonephritis

6 requirements for handling and storing reagent strips:

-store with desiccant in an opaque, tightly sealed container -remove strips immediately prior to use -do not expose to volatile fumes -store below 30 degrees C -do not use past expiration date -visually inspect for discoloration/deterioration

4 causes of benign proteinuria:

-strenuous exercise -high fever -dehydration -exposure to cold

4 causes of acute tubular necrosis:

-toxic substance -heavy metals -viral infections -Fanconi syndrome (generalized proximal convoluted tubule defect)

6 causes of hemoglobinuria:

-transfusion reactions -hemolytic anemias -severe burns -infections/malaria -strenuous exercise/red blood cell trauma -brown recluse spider bites

5 conditions that cause renal glycosuria:

-tubular reabsorption disorder -end-stage renal disease (ESRD) -cystinosis -Fanconi syndrome -temporary lowering of renal threshold in pregnancy

3 causes of false-positive Ictotest:

-urine pigment -pyridium -drugs indican, iodine

The blood level at which tubular reabsorption stops (renal threshold) for glucose is ____________________

160-180 mg/dL

Clinical proteinuria value:

30 mg/dL (300 mg/24 h)

pH of normal random samples:

4.5-8.0

Any amount of blood greater than __________________ is considered clinically significant

5 cells/microliter of urine

Normal protein levels in the blood:

<10 mg/dL or 100 mg/24 h

It may be necessary to perform tests on serial dilutions to provide more information as to the extent of ketosis; these are performed using a tablet test known as ______________; it provides sodium nitroprusside, glycine, disodium phosphate, and lactose in tablet form

Acetest test

The reagent strip test for nitrite provides a rapid screening test for the presence of ____________

UTI

Myoglobin

a heme-containing protein found in muscle tissue, not only reacts positively with the reagent strip test for blood but also produces a clear red-brown urine

______________ is the primary protein of concern

albumin

__________________ has been associated with false-negative reagent strips reactions for blood

ascorbic acid >25 mg/dL

The appearance of ______________ in the urine can provide an early indication of liver disease

bilirubin

Describe positive Icotest for bilirubin: Describe negative test:

blue-purple color appears on mat colors other than blue or purple appear

hormones

breaks down glycogen into glucose

_________________, a frequent constituent of renal calculi, precipitates primarily in acidic and not alkaline urine

calcium oxalate

Make up of reagent strips:

chemical-impregnated absorbent pads on a plastic strip

__________________ bilirubin is water soluble; it appears in urine when normal degradation cycle is disrupted by obstruction of the bile duct or when the integrity of the liver is damaged

conjugated

insulin

converts glucose to storage glycogen

The principle of the reagent strip for _______________ is based on the pseudoperoxidase activity of copper-creatine complexes

creatinine

Advantage of LE test:

detects the presence of lysed leukocytes

The development of _________________ leading to reduced glomerular filtration and eventual renal failure is common occurrence in persons with both type 1 and type 2 diabetes mellitus

diabetic nephropathy

_______________ are present in Trichomonas and histocytes

esterases

A primary example of proteinuria due to increased serum protein levels ______________________

excretion of Bence Jones protein in Multiple Myeloma

Proteinuria associated with true renal disease may be the result of either _______________ or ______________

glomerular or tubular damage

The _____________ test is the most frequent chemical analysis performed on urine; blood and urine tests are included in all physical examinations and are often the focus of mass health screening programs

glucose

Conjugation of bilirubin occurs with __________________

glucuronic acid

_________________ occurs in the absence of hyperglycemia when the reabsorption of glucose by the renal tubules is compromised

glycosuria

__________________ is most closely related to disorders of renal or genitourinary origin in which bleeding is the result of trauma or damage to the organs of these systems

hematuria

Blood may be present in the urine either in the form of intact RBCs, _________________, or as the product of RBC destruction, _________________

hematuria hemoglobinuria

Cloudy red urine = Clear red urine =

hematuria hemoglobinuria

___________________ may result from the lysis of red cells produced in the urinary tract, particularly in dilute, alkaline urine

hemoglobinuria

This condition shows increased unconjugated bilirubin and increased urobilinogen

hemolytic disease

______________ and ______________ are common examples of conditions that produce liver damage, resulting in bilirubinuria; with these conditions, bilirubin leaks back into circulation from damaged liver and some bilirubin passes to intestine

hepatitis cirrhosis

The major source of error with reagent strips occurs with ___________________ that overrides the acid buffer system, producing a rise in pH and a color change unrelated to protein concentration

high buffered alkaline urine

The higher the concentration of urine, the more _____________ ions are released

hydrogen

pH of greater than 8.5 is indicative of what?

improperly preserved specimen (aged)

Clinical reasons for increased fat metabolism:

inability to metabolize carbohydrate inadequate intake of carbohydrate

diabetic ketoacidosis

increased accumulation of ketones in the blood

epinephrine

inhibits insulin; seen with stress, cerebral trauma, and MI

The term ____________ represents three intermediate products of fat metabolism; they appear in urine when body stores of fat must be metabolized to supply energy

ketones

________________ shows a deficiency in insulin indicating the need to regulate dosage

ketonuria

_________________ test is a standardize means for the detection leukocytes

leukocyte esterase (LE)

Infections caused by Tichomonas, Chlamydia, yeast, and inflammation of renal tissues produce ___________________ without bacteriuria

leukocyturia

__________________ serum proteins are filtered; many are reabsorbed

low-molecular-weight

___________ and __________ are major regulators of acid-base content in the body

lungs kidneys

Clinical significance of urine glucose:

major screening test for diabetes mellitus

False-positive reactions for blood in urine may be due to ________________

menstrual contamination

Estimates of ____________ are also provided for many of the test areas

mg/dL

The presence of ___________________ is also associated with an increased risk of cardiovascular disease

microalbuminuria

Hemolytic disease Urine bilirubin results: Urobilinogen results:

negative 3+

A persistent benign proteinuria occurs frequently in young adults and is termed _______________; it occurs following periods spent in a vertical posture and disappears when a horizontal position is assumed; increased pressure on the renal vein in when in the vertical position is believed to account for this condition

orthostatic proteinuria

Depending on the laboratory population, Clinitest is often performed on ________________ specimens from patients up to at least the age of ____________; its major use is quick screen for "inborn error of metabolism"

pediatric 2 years

bilirubin

pigmented yellow compound; is a degradation product of hemoglobin

Bile duct obstruction Urine bilirubin results: Urobilinogen results:

positive (+ + +: 3+) normal

_______________ specimens are more alkaline

postprandial

__________________ is caused by conditions affecting the plasma, not the kidney, prior to its reaching the kidney and, therefore, is not indicative of actual renal disease

prerenal proteinuria

Of the routine chemical tests performed on urine, the most indicative of renal disease is the ____________ determination; the presence of ______________ is often associated with early renal disease

protein proteinuria

_______________ provide a simple, rapid means for performing routine chemical tests on urine

reagent strips

How does glomerular damage lead to proteinuria:

selective filtration is impaired and causes increased protein filtration leading to cellular excretion

Multiple myeloma confirmation test is _________________

serum electrophoresis

pH of first morning specimen:

slightly acidic (5.0-6.0)

What is the purpose of the creatinine measurement?

to correlate the albumin concentration to the urine concentration

True/False Demonstration of proteinuria in a routine analysis does not always signify renal disease; however, its presence does require additional testing to determine whether the protein represents a normal or pathologic condition

true

True/False Nitrite is clinically significant

true

True/False No absolute values are assigned to urinary pH

true

True/False No creatinine results are abnormal for urine

true

True/False a small amount of urobilinogen is always found in urine

true

Increased albumin is also present in disorders affecting __________________ because the normally filtered albumin can no longer be reabsorbed

tubular reabsorption

__________________ bilirubin is water insoluble

unconjugated

____________ is the pigment responsible for the characteristic brown color of feces

urobilin

___________________ is reabsorbed into circulation and __________________ is not (it is oxidized to urobilin

urobilinogen stercobilinogen

Bilirubin in the intestine is converted to _____________________ and _____________________

urobilinogen stercobilinogen

hemosiderin

yellow-brown granules in sediment

Improper technique errors:

-formed elements such as red and white blood cells sink to the bottom of the specimen and will be detected in an unmixed specimen -allowing the strip to remain in the urine for an extended period -excess urine remaining on strip after removal causes run over between chemicals -timing for reactions to take place varies between tests and manufacturers -good light source is essential -strip must be held close to the color chart without actually being placed on chart -specimens that have been refrigerated must be allowed to return to room temp prior to strip testing

4 commonly found reducing sugars:

-galactose -fructose -pentose -lactose

4 types of renal proteinuria:

-glomerular proteinuria -microalbuminuria -orthostatic (postural) proteinuria -tubular proteinuria

5 hormones that oppose glucose:

-glucagon -epinephrine -cortisol -thyroxine -growth hormone

False-positive readings of reagent strips can be due to what 3 things:

-highly pigmented urine -high SG -quaternary ammonium compounds, detergents, antiseptics, chlorhexidine

4 causes of increased pressure on the glomerular filtration mechanism:

-hypertension -strenuous exercise -dehydration -pregnancy

Increased urine urobilinogen is seen in what 2 conditions:

-liver disease -hemolytic disorders

2 ways to read reagent strips:

-manual method -instrument (automated method)

8 causes of myoglobinuria:

-muscular trauma/crush syndromes -prolonged coma -convulsions -muscle-wasting diseases -alcoholism/overdose -drug abuse -extensive exertion -cholesterol-lowering statin medications

Several degrees of color are shown to provide semiquantitative readings of:

-negative -trace -1+ -2+ -3+ -4+

3 causes of false-negative Icotest:

-old specimen -ascorbic acid >25 mg/dL -nitrite

Examples of chemical analysis using reagent test strips:

-pH -protein -glucose -ketones -blood -bilirubin -urobilinogen -nitrite -leukocytes -specific gravity

6 hormonal disorders causing nondiabetic glycosuria:

-pancreatitis -pancreatic cancer -acromegaly -Cushing's syndrome -hyperthyroidism -pheochromocytoma

8 major causes of hematuria"

-renal calculi -glomerular disease -tumors -trauma -pyelonephritis -exposure to toxic chemicals -anticoagulants -strenuous exercise

7 important clinical significances of urine pH:

-respiratory or metabolic acidosis/ketosis -respiratory or metabolic alkalosis -defects in renal tubular secretion and reabsorption of acids and bases (renal tubular acidosis) -renal calculi formation -treatment of UTIs -precipitation/identification of crystals -determination of unsatisfactory specimens

_______________ is the confirmatory test for bilirubin; kits consist of testing mats and tablets containing p-nitrobenzene-diazonium-p-toluenesulfonate, SSA, sodium carbonate, and boric acid

Icotest

4 clinical significances of Le test:

-bacterial and nonbacterial UTI -inflammation of UT -screening of urine culture specimens in conjunction with nitrite but a better predictor than nitrite -seen with Tichomonans, chlamydia, yeast, interstitial nephritis

3 ketones:

-acetone (2%) -acetoacetic acid (20%) -beta-hydroxybutyric acid (78%)

3 primary causes of increased inability to metabolized carbohydrates and inadequate intake of carbohydrate:

-diabetes mellitus -vomiting (loss of carbohydrates) -starvation, malabsorption, dieting (decreased intake)

This test is the test used to detect other sugars; it is not as sensitive as the glucose test, so the finding of a 1+ reagent strip reading and a negative result of this test should not be surprising

Clinitest test