Introduction to Clinical Microscopy (Urinalysis)

Hippocrates

Who wrote a book about uroscopy?

Color charts

It describes the significant 20 different urine colors.

Frederik Dekkers

He discovered Albuminuria by boiling the urine sample.

Richard Bright

Who introduced the Urinalysis as part of the routine patient examination?

Urine Characteristics of a Urine Specimen

• Readily available

• Easily collected

• Contains info about many of the body’s major metabolic function

average 1200 milliliters

Daily Urine Output

Urine

It is an ultrafiltrate of the plasma, it is used to evaluate and monitor body homeostasis and many metabolic diseases.

Urine Composition

95% Water; 5% Solutes

Organic and Inorganic

2 types of Urine Solutes

Urea

What is the primary organic solute?

Urea

It is a metabolic waste product in the liver, from the breakdown of the protein and amino acids.

Urea

It accounts for nearly half of the total dissolved solids in the urine.

Creatinine

It is the product of creatine metabolism by muscles.

Uric Acid

It is the product of nucleic acid breakdown in food and cells.

NaCl

What is the primary inorganic solute?

NaCl

It is the major inorganic solid dissolved?

Potassium, Sulfate, Phosphate, Ammonium, Magnesium, Calcium

What are other inorganic solutes?

Formed Elements

It is normally found in the urine but if it is increased in amount this indicates that the patient has underlying disease.

Dietary Intake, Physical Activity, Body Position, Body Metabolism, Endocrine Functions

What are the factors that influence variation in concentration of the solutes?

Water

It is the major body constituent that will determine the body’s state of hydration.

1200 milliliters 1200 milliliters

Normal Urine Output

Oliguria

It is a decrease in urine output.

1mL/kg per hour

Infants urine output in Oliguria?

less than 0.5 mL/kg per hour

Children urine output in Oliguria?

less than 400 mL/day

Adults urine output in Oliguria?

Anuria

It is the cessation of urine flow.

Oliguria

The body enters a state of dehydration. Excessive water loss from diarrhea, vomiting, perspiration or severe burkes.

Anuria

Resulting from serious damage to the kidneys or decrease in the blood.

Nocturia

The increase in the normal excretion of the urine.

Polyuria

It is the increase daily urine volume that is greater than 2.5 L/day in adults, 2.5 to 3mL/kg per day in children.

Polyuria

It is associate with Diabetes Insipidus and Diabetes Mellitus. It can be artificially induced by ingesting or if the patient has taken diuretics, caffeine/coffee, alcohol; suppresses the antidiuretic hormone (ADH).

Diabetes Mellitus

It is a defect in pancreatic production of insulin and function of insulin. It also causes increase in the body’s glucose formation. Urine is dilute and SG is high.

Diabetes Insipidus

The decrease production or function of ADH. Urine is diluted and SG is lower.

Polydipsia

The increased ingestion of water; the greater amount of urine volume thus the patient has polyuria.

First Morning Specimen

This type or urine specimen is collected immediately on rising from sleep, retained in the bladder for appx. 8 hours.

Random Specimen

This type or urine specimen is the most commonly received in the laboratory and useful for screening test.

24 Hour Specimen

This type or urine specimen is for quantitative urine assay.

Predetermined Length of Time.

This type of timed urine collection is for analytes such as albumin, creatinine or albumin to creatinine ratio.

collection during a specific time of the day

This type of timed urine collection is a 2 hour collection for determination for urobilinogen, maximal excretion from this time.

Fasting Specimen

The 2nd urine voided specimen after fasting, ideal for glucose monitoring.

Two-Hour Post Prandial Specimen

In this urine specimen, the patient should void their urine first before consuming the routine meal and then after 2 hours of eating specimen is collected and tested for glucose.

Glucose Tolerance Specimens

This urine specimen is especially true for pregnant women, subjected to glucose tolerance to determine if they are at risk for gestational diabetes.

Prostatic Specimen

This specimen is for the determination of prostatic infection.

• Three Glass Collection Procedure

• Pre and Post Massage Test (PPMT)

2 Types of Prostatic Specimen Collection

Routine Void

This urine collection technique requires no patient preparation. Simply have the

patient urinate in an appropriate container.

Midstream Clean Catch Specimen

It is the most commonly used collection technique.

Suprapubic Aspiration

It is an invasive collection technique. because it uses a needle and syringe, external introduction of a needle through the abdomen directly into the bladder.

Catheterized Specimen

It is collected under sterile conditions and it is most commonly used in bacterial culture.

Pediatric Specimen

This collection technique uses soft clear plastic bags with a hypoallergenic skin adhesive attached to the genital area.

Color - Modified/Darkened

What analyte changes in oxidation or reduction of metabolites?

Clarity - Decreased

What analyte changes in Bacterial growth and precipitation of amorphous material?

Odor - Increased

What analyte changes in Bacterial multiplication causing breakdown of urea to ammonia?

pH - Increased

What analyte changes in breakdown of urea to ammonia by urease-producing bacteria or loss of CO2?

Glucose - Decreased

What analyte changes in glycolysis?

Ketones - Decreased

What analyte changes in volatilization and bacterial metabolism?

Bilirubin - Decreased

What analyte changes in exposure to light or photo oxidation to biliverdin?

Urobilinogen - Decreased

What analyte changes in oxidation to urobilin?

Nitrite - Increased

What analyte changes in multiplication of nitrate-reducing bacteria?

Red and White Blood Cells

What analyte changes in disintegration in dilute alkaline urine?

• Bactericidal

• Inhibit urease

• Preserve formed elements

• Not interfere with chemical tests

Ideal Urine Preservative

Refrigeration

It is the most routinely used urine specimen preservation that prevents bacterial perforation, suitable for culture up to 24 hours.

4 to 8

pH of urine

1.002 to 1.035

specific gravity of urine

Creatinine

It is the single most useful substance that identifies if the fluid is urine.