Transcript Routine Urine Analysis Identification of Normal Physical and

KAU-Faculty of Science- Biochemistry department
Clinical biochemistry lab (Bioc 416) 2012
T.A Nouf Alshareef
[email protected]
Urine:
• Is an ultrafiltrate of plasma from which glucose, amino acids, water and
other substances essential to body metabolism have been reabsorbed.
• Urine carries waste products and excess water out of the body.
Urine consists of:
(96%)
water
(4%)
dissolved solids:
(2%)
Urea: (half)
(2%)
Other compounds
Inorganic:
Cl-, Na, K.
trace amounts of:
sulfate, HCO3 etc.)
Organic:
creatinine
uric acid
Factors affect on urine constituents:
• dietary intake,
• physical activity,
• body metabolism,
• endocrine function
• others.
Urine Analysis:
Routine Urinalysis (Routine-UA):
• It consists of a group of tests performed as part of physical
examination. It involves macroscopic and microscopic analysis.
Type of analysis:
• macroscopic analysis:
physical characteristics
chemical analysis
• microscopic examination: urine sediment is examined under microscope
to identify the components of the urinary sediments.
Steps in basic urine analysis
Three steps analysis:
First: physical characteristics of urine are noted and recorded.
Second: series of chemical tests is run.
Third: urine sediment is examined under microscope to identify the
components of sediments.
Urine Collection:
Types of urine specimens:
• type of specimen and collection procedure are determined by
physician and depend on the tests to be performed.
There are basically four types of urine specimens:
1. First morning specimen
2. Random urine specimen
3. Fractional collection
4. Timed collection
• Composition and concentration of urine changes during 24hr
• Urine conc. vary according: to water intake and physical activities.
Truly representative sample:
• it is necessary to regulate: time of collection, length of collection
period, patient's dietary, medical intake and method of collection.
• Initial morning sample is preferred (particularly for protein
analysis) because they are more concentrated from overnight
retention in bladder.
• Time of analysis:
- must analyzed within 1h at room temp. or within 8hr at 2oC- 8oC
- If not assayed within these time limits, several changes will occur.
• sample should collected in a clean container.
• urine container must be sterile if the urine is to be cultured.
• For microscopic examination, the urine must be fresh.
• direct visual observation.
• Normal fresh urine: Color: pale or dark yellow-amber, clear.
• Vol:750 - 2000 ml/24hr.
• Physical examination involves:
1. Color
2. Transparency
3. Odour
4. Volume
5. pH
6. Specific gravity
1- Color:
• Color intensity of urine correlates to concentration.
• Darker color means more concentrated sample.
• Amber yellow
Urochrome
(derivative of urobilin, produce from bilirubin degradation,
is pigment found in normal urine).
• Colorless
due to reduced concentration.
• Silver or milky appearance
• Reddish brown
• Yellow foam
Pus, bacteria or epithelial cells
Blood (Hemoglobin).
Bile or medications.
• Orange, green, blue or red
medications.
2- Transparency:
• Is classified as clear or turbid.
• In normal urine: the main cause of cloudiness is crystals and
epithelial cells.
• In pathological urine: it is due to pus, blood and bacteria.
• Degree of cloudiness depends on: pH and dissolved solids
 Turbidity: may be due to gross bacteriuria,
 Smoky appearance: is seen in hematouria.
 Thread-like cloudiness: is seen in sample full of mucus.
3- Odour:
Odour has little diagnostic significance.
1.Aromatic odour------> Normal urine due to aromatic acids.
2.Ammonia odour------> On standing due to decomposition of urea.
3.Fruity odour--------> Diabetes due to the presence of ketones.
4- Volume:
• Is important part of assessment for fluid balance and kidney
functions.
• Adults produce from 750ml-2500ml / 24h, with the average of
about 1.5L per person.
• For RUA, a 10ml-12ml of sample is optimal for accurate of
analysis
5- pH:
• pH measure acidicity or alkalinity (basic) of urine
• Normal urine pH: 4.5-8.
• Increased acidity in urine: due to diabetes or medications.
• Urine sample must be fresh (why?)
(on standing urine become alkaline as a result of ammonia liberation
due to urea decomposition).
6- Specific Gravity (SG):
• measures the amount of substances dissolved in urine.
• also indicates how well kidneys are able to adjust amount of
water in urine.
• higher SG: more solid material is dissolved in urine
Organic: urea, uric acid, creatinine
Inorganic: Cl-, PO4-3, HBO3, NH4, SO4-2
1- Urea:
1ml urine + 3ml NaOCL (sodium hypochlorite) ==>Evolution of N2 gas.
2- Uric acid UA:
1ml urine + 0.5 ml 10% NaOH +1ml Folins reagent ===> Blue color.
3- Creatinine:
- 1ml urine + drops Picric acid + drops NaOH ====> red color ppt.
Note: if reaction is acidified with HCL, the color changes to yellow.
4- Chloride:
- 1ml urine + drops HNO3 +1 ml AgNO3===> white ppt of AgCL
5- Phosphate:
1ml urine + 1ml conc. HNO3 + 1ml NH4-molybdate===>Yellow color.
6- Carbonate:
1ml urine + drops conc. HCL ==> Na2CO3 + 2 HCL ==> H2O + 2NaCL + CO2
(effervescence)
7- Ammonia:
- Make urine alkaline with NaOH. Close the tube with a cork containing another
side tube dipped in Nessler's reagent. Heat the urine and then notice the
evolving of NH3 in Nessler's reagent
- Detect NH3 by its odour.
- 1ml urine + 1ml phenol + 1ml NaBr =======> Blue color.
8- Sulphates:
- 1ml urine + 2 drops conc. HCL + few drops BaCL2 ===> White ppt of BaSO4.
SO4 + BaCL2 =====> BaSO4 + 2CL-
Lab Practices:
• Collect urine in a clean container.
• Run routine UA on the sample by using both urine strip and
the method described before for chemical analysis.
• Record the results in the lab report of UA.
http://human-physiology---ashley-vg.wikispaces.com/Urology
http://nursingcrib.com/medical-laboratory-diagnostic-test/nursing-considerations-for-routine-urinalysis/
http://ahdc.vet.cornell.edu/clinpath/modules/ua-rout/ua-rout.htm