Introduction to Urinalysis

Uroscopy

5th century BCE, wrote a book on

Urinalysis

core test performed in the laboratory

Color Chart

By 1440 CE, (blank) describe the significance 20 different color

Art of Uroscopy

In Middle age, physician were trained

Charlatan

without medical credentials offering prediction to the public for a healthy fee

The Pisse Prophets

published by Thomas Bryant in 1627

Frederik Dekkers

discover in 1694 of albuminuria in patient with kidney problem

Albumin

White precipitate

Proteinuria

abnormal - can no longer filter properly

17th Century

Invention of the microscope

Addis Count

quantifying the cells developed by Thomas Addis of methods for quantitating the microscopic sediment

Richard Bright

introduce the concept of urinalysis of part of a doctor’s routine patient examination in 1827

Clinical and Laboratory Standards Institute (CLSI)

define urinalysis as the testing of urine with procedures commonly performed in an expeditious reliable, accurate, safe, and cost effective manner

Manual Urinalysis

15-30 minutes

Automated Version

within 6 minutes

10 - 15 mL

average amount

Sediment or Microscopic Examination

gold standard of examining urine

Urine

product of filtered blood

Biproduct

toxic waste substances

1200-1500 mL

Average daily urine output

600 mL - 2000 mL

Normal urine volume

Phenylketonuria

can not metabolized amino acid

Tyrosine

phenylalanine should be metabolized by

95% water and 5% solutes

urine consist of normally

Urea

metabolic waste produced in the liver from the breakdown of protein and amino acid

Chloride

major inorganic solid solid dissolve in urine

Protein and Glucose

not present in normal urine specimen

Oliguria

decrease in urine output, 1mL/kg/hour in infant, less than 0.5 mL/kg/hr in children and less than 400 mL/day in adults

Anuria

cessation of urine flow, may results from any serious damage to kidney or from a decrease in the flow of blood to the kidneys

Nocturia

increase in the nocturnal excretion of urine

Polyuria

an increase in daily urine volume (greater than 2.5 L/ day in adults and 2.5 to 3mL/kg/day in children), associated with diabetes insipidus

Diabetes insipidus

cause polyuria: decreased SG, decreased production or function of ADH

Diabetes mellitus

caused by polyuria: increased SG, decreased insulin, decreased function of insulin

Refrigeration

cause precipitation of amorphous urate and phosphate crystals

Ideal Preservative

bactericidal, inhibit urease and preserve formed elements in the sediment

Random Specimem

most commonly because of it ease of collection and convenience for the patient, collected at any time

Random specimen

useful for routine screening test to detect obvious abnormalities but may show erroneous results resulting from dietary intake or physical activity

First morning specimen

ideal screening specimen, essential for preventing false-negative pregnancy test, and evaluating orthostatic protein

24 Hour

quantitative chemical test

Catheterized

bacterial culture

Midstream clean-catch

routine screening and bacterial screening

Suprapubic aspiration

bladder urine for bacterial culture, cytology

Three-glass collection and Four-glass collection

prostatic infection

Refrigeration

advantage: does not interfere with chemical tests

disadvantage: precipitates amorphous phosphates and urates

Acids (boric acid, HCl, acetic acid, tartaric acid)

advantage: prevents bacterial growth and metabolism

disadvantage: interferes with analysis of drugs and hormones

Formalin

advantage: excellent sediment preservative

disadvantage: acts as a reducing agents, interfering with chemical test for glucose, blood, leukocyte esterase and copper reduction

Sodium fluoride

advantage: good preservatives for drugs analysis

disadvantage: inhibits reagent strip tests for glucose, blood and leukocytes

Commercial preservative tablets

advantage: convenient when refrigeration not possible, have controlled concentration to minimize interference

disadvantages: check tablet composition to determine possible effects on desired test

Urine Collection Kits

contains collection cup, transfer straw culture and sensitivity preservatives tube, or UA tube

Light fray and gray C&S tube

advantage: specimen stable at room temperature for 48 hours, prevents bacterial growth and metabolism

disadvantage: do not use if urine is below minimum fill line

Yellow UA Plus tube

advantage: use on automated instruments

disadvantage: must refrigerate within 2 hours

Cherry red/ yellow Preservatives Plus tube

advantage: specimen stable for 72 hours at RT; instrument-compatible

disadvantage: must be filled to minimum fill line; bilirubin and urobilingen may be decreased if specimen is exposed to light and left at RT