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URINALYSIS (MLT 305)

The Open Note Project

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BLOOD

REAGENT STRIP REACTIONS

- Two color charts are provided that correspond to the

reactions that occur with hemoglobinuria and hematuria.

- In the presence of free hemoglobin:

-A strongly positive blue will appear on the pad.

- In contrast, intact red blood cells:

-A speckled pattern will appear on the pad.

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BLOOD

CLINICAL SIGNIFICANCE OF URINE BLOOD

Hematuria

1. Renal calculi

2. Glomerulonephritis

3. Pyelonephritis

4. Tumors

5. Trauma

6. Exposure to toxic chemicals or drugs

7. Strenuous exercise

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BLOOD

CLINICAL SIGNIFICANCE OF URINE BLOOD

Hemoglobinuria

1. Transfusion reactions

2. Hemolytic anemia

3. Severe burns

4. Infections

5. Strenuous exercise

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BLOOD

CLINICAL SIGNIFICANCE OF URINE BLOOD

Myoglobinuria

1. Muscular trauma

2. Prolonged coma

3. Convulsions

4. Muscle-wasting diseases

5. Extensive exertion

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BILIRUBIN

- The appearance of bilirubin in the urine is the first

indication ofliver disease and is often detected

long before the development of jaundice.

- Bilirubin provides early detection of hepatitis,

cirrhosis, gallbladder disease, and cancer, andshould be included in every routine urinalysis.

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Bilirubin

Bilirubin, a highly pigmented yellow compound, is a degradation

product of haemoglobin

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Bilirubin

OXIDATION TESTS (FOUCHETS TEST)

- Urine containing bilirubin usually appears dark yellow or

amber and produces a yellow foam when shaken, thisfoam test was actually the first test for bilirubin.

- Oxidation tests utilize the ability of feric chloride dissolved

in trichloracetic acid (Fouchet's reagent) to oxidizebilirubin to biliverdin, producing a green color.

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Bilirubin

REAGENT STRIP (DIAZO) REACTIONS

- Routine testing for urinary bilirubin by reagent striputilizes the diazo reaction, in an acid medium to produce

colors ranging from increasing degrees of tan or pink toviolet, respectively.

- Questionable results should be retested using theIctotest which produces a more sharply colored diazoreaction.

- Colors other than blue or purple appearing on the matare considered negative.

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Bilirubin

CLINICAL SIGNIFICANCE OF URINE BILIRUBIN

1. Hepatitis

2. Cirrhosis

1. Biliary obstruction

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Bilirubin

- The presence or absence of bilirubin can be used in

determining the cause of clinical jaundice.

( Urine Bilirubin and Urobilinogen in Jaundice )Urine Bilirubin Urine Urobilinogen

Bile duct obstruction +++ Negative

Liver damage + or- ++

Haemolytic disease Negative +++

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UROBILINOGEN

- Like bilirubin, urobilinogen is a bile pigment thatresults from the degradation of hemoglobin.

- It is produced in the intestine by the oxidation ofbilirubin by the intestinal bacteria.

-Approximately half of the urobilinogen is

reabsorbed from the intestine into the blood,recirculates to the liver, and is secreted back intothe intestine through the bile duct.

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UROBILINOGEN

- The urobilinogen remaining in the intestine is excreted inthe feces, where it is oxidized to urobilin, the pigmentresponsible for the characteristic brown color of thefeces.

- Urobilinogen appears in the urine because, as itcirculates in the blood en route to the liver, it passesthrough the kidney and is filtered by the glomerulus.

-A small amount of urobilinogen less than 1 mg/dl or 1Ehrlich unit is normally found in the urine.

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UROBILINOGEN

EHRLICH'S TUBE TEST

- The reagent used in all tests was

p-dimethylaminobenzaldehyde (Ehrlich'sreagent), addition of Ehrlich's reagent to urinecontaining urobilinogen produces a cherry redcolor.

- Positive results in dilutions greater than 1 to 20were considered significant.

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UROBILINOGEN

EHRLICH'S TUBE TEST

- An Ehrlich unit is essentially equal to 1 mg ofurobilinogen.

- Normal values for females are 0.1 to 1.1 Ehrlichunits; and for males, 0.3 to 2.1 Ehrlich units,

these values are based on the recommended 2-hour specimen collected after the noon mealbetween 2 and 4 PM, which is the time ofgreatest urobilinogen excretion.

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UROBILINOGEN

CLINICAL SIGNIFICANCE OF URINE UROBILINOGEN

1.Early detection ofliver disease

2.Hemolytic disorders

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NITRITE

- The reagent strip test for nitrite provides a rapid

screening test for the presence of urinary tractinfection.

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NITRITE

REAGENT STRIP REACTIONS

- Nitrite is detected by the Greiss reaction:

- nitrite at an acidic pH reacts with an aromatic

amine to form a diazonium compound that react

with quinolin compound to produce a pink color.

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NITRITE

CLINICAL SIGNIFICANCE OF URNE NITRITE

1. Cystitis (initial bladder infection)

2.Pyelonephritis (an inflammatory process of thekidney and adjacent renal pelvis)

3.Evaluation of antibiotic therapy

4.Monitoring of patients at high risk for urinarytract infection

5.Screening of urine culture specimens (detectionof bacteruria)

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SPICIFIC GRAVIIY

- The addition of a specific gravity testing area toMultistix has eliminated:

time-consuming step in routine urinalysis

provided a convenient method for routinescreening.

- It is not recommended to replace osmometry orrefractometry for critical fluid monitoring.

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SPICIFIC GRAVIIY

REAGENT STRIP REACTION

- The test is based on the change in pK-

(dissociation constant) of poly methyl vinyl-

ethermaleic anhydride.

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SPICIFIC GRAVIIY

CLINICAL SIGNIFICANCE OF URINE SPECIFIC CRAVITY

1.Patient hydration and dehydration

2. Loss of renal tubular concentrating ability

3.Diabetes insipidus

4.Determination of unsatisfactory specimens due

to low concentration

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LUKOCYTES

- One of the most frequent findings in the routine

urinalysis is the presence ofleukocytes,

indicating a possible infection of the urinary tract.

- Detection ofleukocytes was previously made

only by microscopic examination of the urinarysediment.

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LUKOCYTES

REAGENT STRIP REACTION

- The chemical reaction is enzymatic, utilizing esterases present in granulocyticwhite blood cells to hydrolyze indoxylcarbonic acid ester to produce indoxyl,which reacts with a diazonium salt to create a purple color.

leukocyte

indoxylcarbonic acid ester indoxyl + diazonium salt (purple color)

esterases

- It is recommended that trace reactions be repeated on a fresh specimen and thatmicroscopic examinations be performed on all positive specimens.

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LUKOCYTES

CLINICAL SIGNIFICANCE OF URINE LEUKOCYTES

1.Urinary tract infection

2.Screening of urine culture specimens