Download - Unit #5A – Clinical Laboratory Testing - Urinalysis Cecile Sanders, M.Ed., MLS(ASCP)

Unit #5A – Clinical Unit #5A – Clinical Laboratory Testing - Laboratory Testing -

UrinalysisUrinalysisCecile Sanders, M.Ed., Cecile Sanders, M.Ed.,

MLS(ASCP)MLS(ASCP)

Unit #5A – Clinical Laboratory Unit #5A – Clinical Laboratory Testing - UrinalysisTesting - Urinalysis

Urinary system is Urinary system is an excretory an excretory systemsystem

Renal System Renal System (reproduced with permission (reproduced with permission from Baylor College of from Baylor College of Medicine)Medicine)


Collection and Preservation of Urine Collection and Preservation of Urine – Urinalysis performed for two purposesUrinalysis performed for two purposes

Check for metabolic by-productsCheck for metabolic by-productsObserve physical, chemical and microscopic Observe physical, chemical and microscopic

characteristics characteristics

– Types of SpecimensTypes of SpecimensFirst morning urine specimen is preferred First morning urine specimen is preferred Mid-stream (urine caught from middle of Mid-stream (urine caught from middle of

urine stream) urine stream) Clean catch (patient must cleanse urethral Clean catch (patient must cleanse urethral

opening prior to urinating and catching urine)opening prior to urinating and catching urine)


Handling and preserving specimensHandling and preserving specimens– Examine within 1 hour of collection ORExamine within 1 hour of collection OR– Refrigerate at 4-6° C for up to 8 hoursRefrigerate at 4-6° C for up to 8 hours– Preservatives (least ideal)Preservatives (least ideal)– When urine sits at room temperatureWhen urine sits at room temperature

Bacteria multiplyBacteria multiplyGlucose decreasesGlucose decreasesCasts and cellular elements decomposeCasts and cellular elements decompose


– Color of urineColor of urineYellow – dilute urine is usually lighter in Yellow – dilute urine is usually lighter in

color; concentrated urine is usually darkcolor; concentrated urine is usually darkRed – may have blood presentRed – may have blood presentBrown/black – may be associated with Brown/black – may be associated with

melanomamelanomaYellow-brown or green-brown – may be Yellow-brown or green-brown – may be

associated with liver conditions such as associated with liver conditions such as hepatitis or cirrhosishepatitis or cirrhosis


Light yellow, brown, and dark yellow Light yellow, brown, and dark yellow urinesurines


– TransparencyTransparencyUrine normally transparentUrine normally transparentTurbid – may be associated with crystals Turbid – may be associated with crystals

that settle out of urine at room or that settle out of urine at room or refrigerator temperaturerefrigerator temperature

Cloudy – may be associated with UTI OR Cloudy – may be associated with UTI OR crystalscrystals


– Specific gravity is the ratio of the weight Specific gravity is the ratio of the weight of a given volume of the solution (urine) of a given volume of the solution (urine) to the weight of an equal volume of to the weight of an equal volume of waterwater Indicates concentrations of dissolved Indicates concentrations of dissolved

chemicals such as glucose, salts, etc.chemicals such as glucose, salts, etc.The result of the kidneys’ ability to The result of the kidneys’ ability to

concentrate urineconcentrate urineNormal values – 1.005-1.030 (Ave = 1.015)Normal values – 1.005-1.030 (Ave = 1.015)Usually measured by dip stick or Usually measured by dip stick or

refractometerrefractometer


Chemical Examination of Urine Chemical Examination of Urine – Reagent stripsReagent strips

Test pads are for pH, protein, glucose, ketone, Test pads are for pH, protein, glucose, ketone, bilirubin, blood, urobilinogen, specific gravity, bilirubin, blood, urobilinogen, specific gravity, leukocytes and bacterialeukocytes and bacteria

Used only once and discardedUsed only once and discarded Performing the chemical tests by reagent stripPerforming the chemical tests by reagent strip

– Perform within 1 hour after collection ORPerform within 1 hour after collection OR– Allow refrigerated specimens to return to room Allow refrigerated specimens to return to room

temperaturetemperature– Dip strip in fresh urine and compare color of pads to Dip strip in fresh urine and compare color of pads to

the color chart after appropriate time periodthe color chart after appropriate time period– Instruments are available which detect color changes Instruments are available which detect color changes

electronicallyelectronically


Urine Multistix – reading dipstick Urine Multistix – reading dipstick results manually; colors are matched results manually; colors are matched to those on the bottle label; timing is to those on the bottle label; timing is critical for each pad.critical for each pad.


MultistixMultistix


Bayer Clinitek automatically reads a Bayer Clinitek automatically reads a urine dipstick and prints out resultsurine dipstick and prints out results


Principle of chemical testsPrinciple of chemical tests– pH measures degree of acidity or pH measures degree of acidity or

alkalinity of urinealkalinity of urine– Presence of protein (proteinuria) is an Presence of protein (proteinuria) is an

important indicator of renal disease, important indicator of renal disease, such as pyleonephritissuch as pyleonephritis

– Presence of glucose (glycosuria) Presence of glucose (glycosuria) indicates that the blood glucose level indicates that the blood glucose level has exceeded the renal threshold, such has exceeded the renal threshold, such as in diabetesas in diabetes


– Ketones are excreted when the body metabolizes Ketones are excreted when the body metabolizes fats incompletely (ketonuria), such as in diabetes fats incompletely (ketonuria), such as in diabetes

– Bilirubin is a byproduct of the breakdown of Bilirubin is a byproduct of the breakdown of hemoglobin. Its presence may be an indication of hemoglobin. Its presence may be an indication of liver disease, bile duct obstruction or hepatitisliver disease, bile duct obstruction or hepatitis

– Presence of blood may indicate infection, trauma to Presence of blood may indicate infection, trauma to the urinary tract or bleeding in the kidneysthe urinary tract or bleeding in the kidneys

– Urobilinogen is a degradation product of bilirubin Urobilinogen is a degradation product of bilirubin formed by intestinal bacteria. It may be increased formed by intestinal bacteria. It may be increased in hepatic disease or hemolytic diseasein hepatic disease or hemolytic disease


– Nitrite formed by gram negative bacteria Nitrite formed by gram negative bacteria converting urinary nitrate to nitrite. Presence of converting urinary nitrate to nitrite. Presence of nitrites in fresh urine can indicate infection – in nitrites in fresh urine can indicate infection – in an old urine, nitrites can be positive without an an old urine, nitrites can be positive without an infectioninfection

– Leukocytes usually indicate infectionLeukocytes usually indicate infection– Specific gravity reflects kidney's ability to Specific gravity reflects kidney's ability to

concentrate urineconcentrate urine Normal valuesNormal values

– Negative results for glucose, ketones, bilirubin, Negative results for glucose, ketones, bilirubin, nitrites, leukocyte esterase and bloodnitrites, leukocyte esterase and blood

– Protein negative or traceProtein negative or trace– pH 5.5-8.0pH 5.5-8.0– Urobilinogen 0.2-1.0 Ehrlich unitsUrobilinogen 0.2-1.0 Ehrlich units


ResourcesResources– Basic Clinical Laboratory TechniquesBasic Clinical Laboratory Techniques, ,

Estridge and Reynolds, Thomson/Delmar Estridge and Reynolds, Thomson/Delmar Learning, Fifth Edition, 2008Learning, Fifth Edition, 2008