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

Unit #5A – Clinical Laboratory Testing - Urinalysis Urinary system is an excretory system Renal System (reproduced with permission from Baylor College of Medicine)

Unit #5A – Clinical Laboratory Testing - Urinalysis Collection and Preservation of Urine Urinalysis performed for two purposes Check for metabolic by-products Observe physical, chemical and microscopic characteristics Types of Specimens First morning urine specimen is preferred Mid-stream (urine caught from middle of urine stream) Clean catch (patient must cleanse urethral opening prior to urinating and catching urine)

Unit #5A – Clinical Laboratory Testing - Urinalysis Handling and preserving specimens Examine within 1 hour of collection OR Refrigerate at 4-6° C for up to 8 hours Preservatives (least ideal) When urine sits at room temperature Bacteria multiply Glucose decreases Casts and cellular elements decompose

Unit #5A – Clinical Laboratory Testing - Urinalysis Color of urine Yellow – dilute urine is usually lighter in color; concentrated urine is usually dark Red – may have blood present Brown/black – may be associated with melanoma Yellow-brown or green-brown – may be associated with liver conditions such as hepatitis or cirrhosis

Unit #5A – Clinical Laboratory Testing - Urinalysis Light yellow, brown, and dark yellow urines

Unit #5A – Clinical Laboratory Testing - Urinalysis Transparency Urine normally transparent Turbid – may be associated with crystals that settle out of urine at room or refrigerator temperature Cloudy – may be associated with UTI OR crystals

Unit #5A – Clinical Laboratory Testing - Urinalysis Specific gravity is the ratio of the weight of a given volume of the solution (urine) to the weight of an equal volume of water Indicates concentrations of dissolved chemicals such as glucose, salts, etc. The result of the kidneys’ ability to concentrate urine Normal values – 1.005-1.030 (Ave = 1.015) Usually measured by dip stick or refractometer

Unit #5A – Clinical Laboratory Testing - Urinalysis Chemical Examination of Urine Reagent strips Test pads are for pH, protein, glucose, ketone, bilirubin, blood, urobilinogen, specific gravity, leukocytes and bacteria Used only once and discarded Performing the chemical tests by reagent strip Perform within 1 hour after collection OR Allow refrigerated specimens to return to room temperature Dip strip in fresh urine and compare color of pads to the color chart after appropriate time period Instruments are available which detect color changes electronically

Unit #5A – Clinical Laboratory Testing - Urinalysis Urine Multistix – reading dipstick results manually; colors are matched to those on the bottle label; timing is critical for each pad.

Unit #5A – Clinical Laboratory Testing - Urinalysis Multistix

Unit #5A – Clinical Laboratory Testing - Urinalysis Bayer Clinitek automatically reads a urine dipstick and prints out results

Unit #5A – Clinical Laboratory Testing - Urinalysis Principle of chemical tests pH measures degree of acidity or alkalinity of urine Presence of protein (proteinuria) is an important indicator of renal disease, such as pyleonephritis Presence of glucose (glycosuria) indicates that the blood glucose level has exceeded the renal threshold, such as in diabetes

Unit #5A – Clinical Laboratory Testing - Urinalysis Ketones are excreted when the body metabolizes fats incompletely (ketonuria), such as in diabetes Bilirubin is a byproduct of the breakdown of hemoglobin. Its presence may be an indication of liver disease, bile duct obstruction or hepatitis Presence of blood may indicate infection, trauma to the urinary tract or bleeding in the kidneys Urobilinogen is a degradation product of bilirubin formed by intestinal bacteria. It may be increased in hepatic disease or hemolytic disease

Unit #5A – Clinical Laboratory Testing - Urinalysis Nitrite formed by gram negative bacteria converting urinary nitrate to nitrite. Presence of nitrites in fresh urine can indicate infection – in an old urine, nitrites can be positive without an infection Leukocytes usually indicate infection Specific gravity reflects kidney's ability to concentrate urine Normal values Negative results for glucose, ketones, bilirubin, nitrites, leukocyte esterase and blood Protein negative or trace pH 5.5-8.0 Urobilinogen 0.2-1.0 Ehrlich units

Unit #5A – Clinical Laboratory Testing - Urinalysis Resources Basic Clinical Laboratory Techniques, Estridge and Reynolds, Thomson/Delmar Learning, Fifth Edition, 2008