Routine urine analysis. The urinalysis is a routine screening test which is usually done as a part...
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Routine urine analysis. The urinalysis is a routine screening test which is usually done as a part of a physical examination, during preoperative testing,
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).
Slide 3
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.
Slide 4
Slide 5
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.
Slide 6
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.
Slide 7
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.
Slide 8
PRESERVATION Refrigeration. up to 8 hours is refrigerator at
4-6C. Toluene: used If only the chemical contents of the urine are
of 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.
Slide 9
MACROSCOPIC AND PHYSICAL EXAMINATION OF URINE
Slide 10
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.
Slide 11
Urine color The color of normal urine is caused by the presence
of various 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.
Slide 12
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.
Slide 13
Slide 14
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: 1.0051.030 (random sample
usually 1.0151.025)
Slide 15
pH The usual pH is about 6.0, with a reference range of 4.6 to
8.0.
Slide 16
Urine odor Fresh urine from a healthy patient usually has a
very slight aromatic odor, which is due to certain volatile
constituents.
Slide 17
CHEMICAL TESTS FOR SUBSTANCES IN URINE PROTEIN : Normal Values:
Negative GLUCOSE: Normal Values: Negative KETONES: Normal Values:
Negative UROBILINOGEN: Negative or 0.11.0 Ehrlich units/dL
leukocyte esterase and nitrites: Normal Values: Negative
Slide 18
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 2- 3,000 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.
