Routine urine analysis
 The urinalysis is a routine screening test which is usually done as a
part of a physical examination, during preoperative testing, and
upon hospital admission.
 It is used in the diagnosis of infections of the kidneys and urinary
tract and also in the diagnosis of diseases unrelated to the urinary
system.
 The urinalysis consists of several components including:
appearance, bilirubin, blood, color, glucose, ketones, leukocyte
esterase, nitrites, odor, pH, protein, specific gravity, urobilinogen,
and microscopic examination of sediment (bacteria, crystals,
epithelial casts, fatty casts, granular casts, hyaline casts, red blood
cells and casts, white blood cells and casts).
Urine Formation
 In the normal adult, approximately 1200 mL of blood
perfuses the kidneys each minute, which accounts for
about 25% of the cardiac output.
 The glomeruli (normally numbering at least 1 million
per kidney) receive blood through afferent arterioles,
and an ultrafiltrate of the plasma passes through each
glomerulus into Bowman's space.
 From here the filtrate is passed through the tubules and
collecting ducts where reabsorption or secretion of
various substances and the concentration of urine can
occur.
 This urine formed in the kidneys passes from the
collecting ducts into the renal pelvis, ureters, bladder,
and urethra to be voided.
The kidneys take part in several
regulatory functions.
 eliminated waste products from the body, including
nitrogenous products of protein catabolism, and
both organic and inorganic acids and bases.
 Regulate Fluid, electrolytes (including sodium,
potassium, calcium, and magnesium), and acid–
base.
 provide important hormonal regulation with
erythropoietin and renin production, as well as
vitamin D activation.
Urine sample
 RANDOM SPECIMEN: A random urine specimen is satisfactory
for most qualitative tests and may be collected at any time.
 FIRST MORNING : A first morning sample is collected when
the patient rises in the morning. It is the most concentrated of the
urine samples and is used for qualitative analysis.
 TWO-HOUR POSTPRANDIAL: This specimen is collected
two hours after the patient has eaten a meal, the specimen is tested
for glucose.
 TWENTY-FOUR HOUR SPECIMEN : The 24-hour specimen
is made up of the total urinary output for a specific 24- hour
period and to obtain an accurate timed specimen.
SPECIAL METHODS OF URINE
COLLECTION
 Catheterization : is used for some bacteriological tests
performed on urine.
 Midstream Specimen.
 Suprapubic Aspiration: Urine may be collected by
external introduction of a needle into the bladder.
PRESERVATION
 Refrigeration. up to 8 hours is refrigerator at 4-6ºC.
 Toluene: used If only the chemical contents of the urine are of
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interest, it lies on the surface of the urine, forming a thin layer
and acting as a physical barrier to air and bacteria.
10 % Formalin : is an excellent preservative for the formed
(microscopic) elements in urine.
8% Boric Acid : Boric acid is used for general purposes. It will
not interfere with examinations for protein, sugar, or ketone
bodies.
Chloroform. used as a preservative, but it interferes with some
chemical tests and may cause cellular changes.
Sodium Carbonate. To preserve urobilinogen in urine
requires special precautions.
MACROSCOPIC AND PHYSICAL
EXAMINATION OF URINE
Urine volume
 N.R: 1-2 L/24-h by normal adult.
 Polyuria . increase in the total volume of urine excreted more than 2
L/24-h.
 Oliguria. A reduction in the total volume of urine excreted less than 200
ml/24-h.
 Anuria. This term literally means "no urine" and refers to a complete
lack of urine excretion.
Urine color
 The color of normal urine is caused by the presence of various
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pigments, which are collectively referred to as urochrome.
Yellow. Normal urine has a color of straw, yellow, or amber.
Green and Blue-Green. e.g. Oralcontraceptives, Bile
pigment.
Brown and Black. E.g. Porphyrins. Bilirubin.
Red, Pink, or Reddish-Orange. E.g. Beets. Food colors.
Blood. Hemoglobin.
General appearance of the urine
 Clear. Normal, freshly voided urine is usually clear as it has
no visible particles.
 Hazy. When the sample contains a small amount of
particles, it is designated as hazy.
 Cloudy. Moderate to large amounts of visible particles
produce a cloudy urine.
Specific gravity
 Specific gravity is a comparison of the density of urine to the
density of distilled water, which is regarded as 1.000.
 Normal Values
 Adult: 1.005–1.030 (random sample usually 1.015–1.025)
pH
 The usual pH is about 6.0, with a reference range of 4.6 to
8.0.
Urine odor
 Fresh urine from a healthy patient usually has a very slight
aromatic odor, which is due to certain volatile constituents.
CHEMICAL TESTS FOR SUBSTANCES IN
URINE
 PROTEIN : Normal Values: Negative
 GLUCOSE: Normal Values: Negative
 KETONES: Normal Values: Negative
 UROBILINOGEN: Negative or 0.1–1.0 Ehrlich units/dL
 leukocyte esterase and nitrites: Normal Values:
Negative
THE MICROSCOPIC EXAMINATION OF
URINARY SEDIMENT
 Methodology
 A sample of well-mixed urine (usually 10-15 ml) is
centrifuged in a test tube at relatively low speed (about 23,000 rpm) .
 The supernate is decanted and a volume of 0.2 to 0.5 ml is
left inside the tube.
 The sediment is resuspended in the remaining supernate by
flicking the bottom of the tube several times. A drop of
resuspended sediment is poured onto a glass slide and
coverslipped.
 Red Blood Cells
 WBCs
 Epithelial cells
 Casts
 Crystals
 Yeasts
 Parasites