Laboratory and diagnostic examination(urine analysis)

laboratory investigation like urine and stool test like meaning, type of test, interpretation nurses role in laboratory investigation collectin and transportation etc.

1. LABORATORY AND DIAGNOSTIC EXAMINATION
URINE AND STOOL ANALYSIS :

Urine:
Urine is a liquid by-product of metabolism in humans and in many animals. Urine flows from the
kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from
the body through the urethra.
Urine culture test :
A urine culture is a test to find germs (such as bacteria) in the urine that can cause an
infection. Urine in the bladder is normally sterile. This means it does not contain any bacteria or
other organisms (such as fungi). But bacteria can enter the urethra and cause a urinary tract
infection
Urine analysis :
A urinalysis is a group of physical, chemical, and microscopic tests. The tests detect and/or
measure several substances in the urine, such as byproducts of normal and abnormal metabolism,
cells, cellular fragments, and bacteria.
Process of urine in human body excretion:
Urine is a liquid by-product of metabolism in humans and in many animals. Urine flows from
the kidneys through the ureters to the urinary bladder. Urination results in urine
being excreted from the body through the urethra.
The cellular metabolism generates many by-products which are rich in nitrogen and must
be cleared from the bloodstream, such as urea, uric acid, and creatinine. These by-products are
expelled from the body during urination, which is the primary method for excreting water-

2. soluble chemicals from the body. A urinalysis can detect nitrogenous wastes of
the mammalian body.
Urine has a role in the earth's nitrogen cycle. In balanced ecosystems urine fertilizes the soil and
thus helps plants to grow. Therefore, urine can be used as a fertilizer. Some animals use it
to mark their territories. Historically, aged or fermented urine (known as lant) was also used
for gunpowder production, household cleaning, tanning of leather and dyeing of textiles.
Human urine and feces are collectively referred to as human waste or human excreta, and are
managed with a sanitation system. Livestockurine and feces also require proper management if
the livestock population density is high.

Urine process in bowmen capsule:
Urine is an aqueous solution of greater than 95% water. Other constituents include urea,
chloride, sodium, potassium, creatinine and other dissolved ions, and inorganic and organic
compounds. Urea is a non-toxic molecule made of toxic ammonia and carbon dioxide.

Composition of urine :

3. Type of test :
 Urine Culture
 Urine Protein and Urine Protein to Creatinine Ratio
 Blood Urea Nitrogen (BUN)
 Creatinine
 Urine Albumin and Albumin to Creatinine Ratio
 Kidney Stone Risk Panel
 Kidney Stone Analysis
 Estimated Glomerular Filtration Rate (eGFR)
 Glucose Tests

4.  Renal Panel
 Bilirubin

Conditions
 Urinary Tract Infection
 Protein in Urine (Proteinuria)
 Blood in Urine (Hematuria)
 Kidney Disease
 Pregnancy
 Diabetes
 Hypertension

Urine Specimen
1. Clean-Catch mid-stream urine specimen for routine urinalysis, culture and sensitivity test
 Best time to collect is in the morning, first voided urine
 Provide sterile container
 Do perineal care before collection of the urine
 Discard the first flow of urine
 Label the specimen properly
 Send the specimen immediately to the laboratory
 Document the time of specimen collection and transport to the lab.
 Document the appearance, odor, and usual characteristics of the specimen.
2. 24-hour urine specimen
 Discard the first voided urine.
 Collect all specimens thereafter until the following day
 Soak the specimen in a container with ice
 Add preservative as ordered according to hospital policy
3. Second-Voided urine – required to assess glucose level and for the presence of albumen in
the urine.
 Discard the first urine
 Give the patient a glass of water to drink
 After few minutes, ask the patient to void
4. Catheterized urine specimen
 Clamp the catheter for 30 min to 1 hour to allow urine to accumulate in the bladder and
adequate specimen can be collected.
 Clamping the drainage tube and emptying the urine into a container are contraindicated after
a genitourinary surgery.

5. Stool :Description
Feces, colloquially known as poop, are the solid or semisolid remains of the food that could not
be digested in the small intestine. Bacteria in the large intestine further break down the material.
Composition: Feces are composed of water, protein, undigested fats, polysaccharides, bacterial
biomass, ash, and undigested food residues.
Human feces (or faeces in British English; Latin: fæx) are the solid or semisolid remains of the
food that could not be digested or absorbed in the small intestine of humans, but has been rotted
down by bacteria in the large intestine. It also contains bacteria and a relatively small amount
of metabolic waste products such as bacterially altered bilirubin, and the dead epithelial cells
from the lining of the gut. It is discharged through the anus during a process called defecation.
Human feces have similarities to feces of other animals and vary significantly in appearance (i.e.
size, color, texture), according to the state of the diet, digestive system and general health.
Normally human feces are semisolid, with a mucus coating. Small pieces of harder, less moist
feces can sometimes be seen impacted in the distal (final or lower) end. This is a normal
occurrence when a prior bowel movement is incomplete, and feces are returned from
the rectum to the large intestine, where water is absorbed.
In the medical literature, the term "stool" is more commonly used than "feces".
Human feces together with human urine are collectively referred to as human waste or
human excreta. Containing human feces, and preventing spreading of pathogens from human
feces via the fecal–oral route, are the main goals of sanitation.
Type of stool test :
A stool test is used to detect the presence of blood or other gastrointestinal abnormalities, such
as colon or gastric cancer, inflammatory bowel disease, hemorrhoids, anal fissures or infections.
There are two main types of stool tests to choose from. The first, a fecal occult blood test
(FOBT), detects the presence of blood in your feces. The second, a stool DNA test, detects the
presence of genetic material from polyps and cancerous tumors.
Examination of stool :
Visual examination
The patient and/or health care worker in the office or at the bedside is able to make some
important observations.
 Color
 Texture/consistency—formed
Screening test:

6. One of the most common stool tests, the fecal occult blood test can be used to diagnose many
conditions that cause bleeding in the gastrointestinal system including colorectal
cancer or stomach cancer. Cancers, and to a lesser extent, precancerous lesions, shed abnormal
cells into the stool. Cancers and precancerous lesions (polyps) that are ulcerated or rubbed by
passing stool also may shed blood into the stool, which can be identified by a hemoglobin assay
Microbiology tests
Parasitic diseases such as ascariasis, hookworm, strongyloidiasis and whipworm can be
diagnosed by examining stools under a microscope for the presence of worm larvae or eggs.
Some bacterial diseases can be detected with a stool culture. Toxins from bacteria such
as Clostridium difficile ("C. diff.") can also be identified. Viruses such as rotavirus can also be
found in stools.
Chemical tests
A fecal pH test may be used to determine lactose intolerance or the presence of an infection.
Steatorrhea can be diagnosed using a Fecal fat test that checks for the malabsorption of fat.
Faecal elastase levels are becoming the mainstay of pancreatitis diagnosis
Stool Specimen
1. Fecalysis – to assess gross appearance of stool and presence of ova or parasite
 Secure a sterile specimen container
 Ask the pt. to defecate into a clean, dry bed pan or a portable commode.
 Instruct client not to contaminate the specimen with urine or toilet paper (urine inhibits
bacterial growth and paper towel contain bismuth which interfere with the test result.
2. Stool culture and sensitivity test
 To assess specific etiologic agent causing gastroenteritis and bacterial sensitivity to various
antibiotics.
3. Fecal Occult blood test
 Are valuable test for detecting occult blood (hidden) which may be present in colo-rectal
cancer, detecting melena stool
a. Hematest– (an Orthotolidin reagent tablet)
b. Hemoccult slide– (filter paper impregnated with guaiac)
o *Both test produces blue reaction id occult blood lost exceeds 5 ml in 24 hours.
c. Colocare – a newer test, requires no smear
Instructions
1. Advise client to avoid ingestion of red meat for 3 days
2. Patient is advice on a high residue diet
3. Avoid dark food and bismuth compound
4. If client is on iron therapy, inform the MD
5. Make sure the stool in not contaminated with urine, soap solution or toilet paper
6. Test sample from several portion of the stool.

Role Of Nurses In Laboratory Specimens collection procedure:
1. Check the physician order of laboratory investigation

7. 2. Follow the institutional policy for billing system
3. Arrange the safety precautions prior to specimen collection
4. Explain the investigation order to the patients/relatives to be prepared.
5. Arrange all articles for specimen collection as per guidelines
6. Provide privacy and check the patient convenient
7. Explain the procedure to the patient
8. Follow the cleaning technique prior to the sample collection
9. Perform the hand washing technique
10. Perform the procedure as per SOP
11. Collect the specimen in appropriate container, quantity as per guidelines
12. Transport the specimen to the laboratory by appropriate media .
13. Maintain the documentation date, time ,type of specimen with sign .
14. Collect the report from the laboratory as per protocol.

Results-Interpretation of urine analysis :

Visual examination :
 Urine color
 Urine clarity
 Overview
Chemical examination:
 Specific gravity
 PH
 Bilirubin
 Urobilirubin
 Protein
 Glucose
 Ketones
 Bloog heamoglobin/myoglobin
 Leukocytes
 Nitrite
 Ascorbic acid
Microscopic examination :
 RBCs
 WBCs
 Epithelial cells
 Bacteria, yeast and parasites
 Casts
 Crystals


PREPARED BY
DR.ANJALATCHI M.SC(N) MD(AM) MBA(HA)
ERAS UIVERSITY ,LUCKNOW