INTRODUCTION TO URINALYSIS
• Defined by Clinical and Laboratory Standards sInstitute (CLSI) as “the testing of urine with procedures commonly
... [Show More] performed in an expeditious, reliable, accurate, safe and cost-efficient manner.”
• Requires least amount of pre-analytical preparation
• Aims to assist in the diagnosis of diseases, serves as a screening asymptomatic population for undetected disorders and serves to monitor the progress of disease and effectiveness of therapy.
HISTORY OF CLINICAL MICROSCOPY
Egyptian Hieroglyphics Edwin Smith Surgical Papyrus
Hippocrates (5th century BCE) Book of UROSCOPY
Frederik Dekkers (1694) ALBUMINURIA – demonstrated by boiling urine with white foam formation; can be demonstrated by vigorously shaking the specimen
Thomas Addis Examination and Methods of Quantification of Urinary Sediments; requires 12 hours of urine collection & using formaldehyde as a preservative that prevents disintegration of urinary sediments → cellular lysis and sediment disintegration will begin due to prolonged standing of specimen (2 hours)
Thomas Bryant (1627) Published a book about Charlatans or “PISSE PROPHETS” – publishing of his work led to the passing of the first medical licensure laws in England
Richard Bright (1827) Concept of Urinalysis as a part of the physician’s routine patient examination
2 UNIQUE CHARACTERISTICS OF URINE SPECIMEN FOR PATIENT EVALUATION
1. Urine is readily available and easily collected
2. It contains information, which can be obtained by inexpensive lab tests about many of the body’s major metabolic functions.
SPECIMEN INTEGRITY
• Following collection, urine specimens should be delivered to the laboratory and promptly tested within 2 HOURS
CHANGES IN UNPRESERVED URINE SPECIMEN
INCREASED RATIONALE
pH Urea is split by bacteria, release of Ammonia
Bacteria Multiplication, Metabolic Activity
Odor Ammonia → alkaline material produced from the splitting of urea
Nitrite Nitrate converted by bacteria
DARKENED RATIONALE
Color Oxidation and Reduction of Metabolites
DECREASED RATIONALE
Clarity Bacteria multiplies, substances (like amorphous materials); precipitate → further encouraged by refrigeration
Glucose Glycolysis, used by bacteria
Ketones Volatile acids → byproduct of FA β-oxidation; easily evaporated, easily escapes from the specimen
Bilirubin Photo Oxidation → Conjugated Bilirubin/ B2/ Direct Bilirubin/ Water soluble Bilirubin
Urobilinogen Reduced into Urobilin
RBC, WBC, and their Casts Disintegrates in Alkaline Urine
Trichomonas Becomes immobile or it dies, misidentified as WBCs
• Increased → Alkaline Urine
• Decreased → Turbid Urine
TYPES OF URINE SPECIMEN
Random Sample Routine Urinalysis
First Morning Urine Ideal specimen for routine UA and pregnancy
For well preservation of cells and casts
For evaluation for Orthostatic Proteinuria
Most concentrated & most acidic
Second Morning/ Fasting 2nd voided urine after a period of fasting
For glucose determination
2 Hours Post Prandial For diabetic screening/ monitoring
Glucose Tolerance Optional with blood samples in glucose tolerance test
Fractional Specimen At least 2 voided collections
Series of blood and urine samples are collected at specific time intervals to compare the concentrations of a substance in urine with its concentration in the blood (used in the diagnosis of diabetes)
Midstream Clean Catch Routine UA and Bacteriologic sampling → Asks patients to wash their genitals prior collection to reduce the interference of non-pathogenic bacteria
Catheterized Bacterial Culture (Anaerobic) → directly aspirated from the urinary bladder exposing the sample to the ambient oxygen
Suprapubic Aspiration Anaerobic Bacterial Culture, Urine cytology → preventive cellular constituents from ambient air, since it can distort the morphology of cells present in urine leading to false cancer cell results
Pediatric Specimen Use of Soft, plastic bag with adhesive
Sterile specimen, obtained by catheterization or suprapubic aspiration
3 Glass Technique for Detection of Prostatitis 1. First portion of voided urine
2. Middle Portion of voided urine
3. Urine after prostatic massage
Test for 1st and 3rd sample microscopically, then compare the number of bacteria and WBCs
Prostatic Infection
2nd specimen – If (+) for WBCs and bacteria, the results from the 3rd specimen is considered invalid
3 GLASS TECHNIQUE
• For detection of Prostatitis
• PROSTATITIS – inflammation of the prostate
• 1st – whole urine specimen collected
• 2nd – control → if bacteria is present = INVALID
• 3rd – prostatic massage while collecting the sample
• PURPOSE: To determine if there is a localized infection in the patient’s prostate gland
• Screened microscopically and chemically for the presence of bacteria, pus cells, and leukocytes
• 3rd tube > 1st tube: (+) bacteria and WBC = Prostatitis
• 1st tube > 3rd tube: (+) bacteria and WBC = Lower UTI infection
• 2nd tube: (+) bacteria and WBC, results from 3rd tube is INVALID → control for Kidney and Bladder infection
ALTERNATIVE METHOD FOR PROSTATITIS
• PPMT – PRE AND POST MASSAGE TEST
TIMED SPECIMENS
24 HOURS SPECIMEN CLEARANCE TESTS
12 HOURS SPECIMEN ADDIS COUNT (Preservative: Formaldehyde)
4 HOURS SPECIMEN NITRITE DETERMINATION (abstain from any dietary intake for 4-hours); dietary nitrites can alter the concentration of patient’s nitrite values
AFTERNOON (2-4PM) UROBILINOGEN DETERMINATION
URINE PRESERVATION
REFRIGERATION
Advantage Disadvantage Information
No interference with chemical test Raises SG by Hydrometer
Precipitates amorphous phosphates and urates Prevents bacterial growth for 24 hours
THYMOL
Advantage Disadvantage Information
Preserves glucose and sediments Interferes with Acid Precipitation test for protein
BORIC ACID
Advantage Disadvantage Information
Preserves protein and formed elements well
Does not interfere with Routine analysis other than pH May precipitate crystals when used in large amounts Keeps pH about 6.0
Bacteriostatic at 18g/L and can be used as a culture transport media
Interferes with drug and hormone analysis
FORMALIN/ FORMALDEHYDE
Advantage Disadvantage Information
Excellent for Addis count Reducing agent
Interferes with blood, glucose, leukocytes and copper reduction Rinse specimen container with formalin to preserve cells and casts
TOLUENE
Advantage Disadvantage Information
Does not interfere with routine tests Floats on surface of specimen
Clings to pipette and testing material
SODIUM FLUORIDE
Advantage Disadvantage Information
Prevents glycolysis
Good preservative for drug analysis Inhibits leukocytes, glucose and blood reagent strip May use Sodium benzoate instead of Sodium fluoride for reagent strip testing
PHENOL
Advantage Disadvantage Information
Does not interfere with routine test Causes and odor change Use 1 drop per ounce of urine
COMMERCIAL PRESERVATIVE TABLETS
Advantage Disadvantage Information
Convenient when refrigeration is not possible
Have controlled concentrations to minimize interferences May contain one or more of the preservatives including Sodium fluoride Check tablet composition to determine the possible effects on desired tests
URINE COLLECTION KITS
Advantage Disadvantage Information
Contains collection cups, C and S preservative tubes or UA tubes
GRAY C AND S TUBES
Advantage Disadvantage Information
Stable at room temperature for 48 hours
Preserves bacteria Decreases pH
Do not use if urine is below fill line Preservative is boric acid and may not be used for UA
YELLOW PLAIN UA TUBE
Advantage Disadvantage Information
Used on automated instruments Must be refrigerated within 2 hours Round or conical bottom
CHERRY RED/ YELLOW TOP TUBE
Advantage Disadvantage Information
Stable at room temperature for 72 hours
Instrument compatible Bilirubin and Urobilinogen may be decreased if specimen is not protected from light and left at room temperature Preservative is Sodium propionate
Conical bottom
SACCOMMANO FIXATIVE
50% Ethanol + 2% Carbowax
Advantage Disadvantage Information
Preserves cellular elements Used for cytology studies (50mL of urine is required)
SAMPLING FOR DRUG TESTING
• CHAIN OF CUSTODY – the process that provides documentation of proper sample identification from the time of collection to the receipt of the laboratory
REQUIRED URINE VOLUME:
o 30 ML – 60 ML (NATIONAL REFERENCE LAB)
o 30 ML – 45 ML (STRASINGER)
TEMPERATURE:
o Within 4 MINUTES (32.5C to 37.7C)
o To determine if the sample is fresh and to provide less opportunity for sample tampering/ adulteration
o <32.5C may be mixed with water or reducing substances such Tetrahydrocarabinol & Methampethamine = bleach on urine sample that may alter the concentration of the sample
• We do not consider time of exposure to drugs/ concentration of drugs (applicable only for drug monitoring purposes)
SPLIT SAMPLING
• BOTH BOTTLES = 30mL
• BOTTLE A
Tested for DRUG TESTING
Sent by the Screening Drug Test Laboratory (SDTL) to the National Reference Laboratory (NRL) for confirmatory test
• BOTTLE B
Kept by the SDTL for 15 DAYS in case of RETEST (client requested; patient’s order) or CHALLENGE TEST (court mandated; court order; judge requested)
SINGLE SAMPLING
• The entire 60 ML is tested
• If the single sample is tested positive for drug metabolites. The entire bottle is set by the SDTL to the national reference laboratory for confirmatory testing
• GC-MS reference/ confirmatory method for detecting/ analyzing drug metabolites in all biological specimens
GAS CHROMATOGRAPHY – separation technique
MASS SPECTROMETRY – analyzing step; drug metabolites are quantified
URINE SAMPLING FOR DRUG TESTING
• CONTAINER:
60 ML POLYETHYLENE BOTTLE (SINGLE)
30 ML POLYETHYLENE BOTTLE (SPLIT)
• BLUEING AGAENT (DYE) is added to toilet water reservoir to prevent specimen adulteration
• Authorized Specimen Collector (ASC) – personnel that maintains the chain of custody (client should never see the drug analyst) [Show Less]