Nurses in hospitals and clinics use the following methods to test the urine specimen of their patients before reporting to the doctor(s) in the ward.
Always use fresh specimens of urine for all urine tests. Before carrying out any chemical test, certain observation should be made e.g.
Normal range of colour is pale and amber, but usually varies with concentration except in urine of client with diabetes mellitus due to presence of sugar.
Abnormalities of colour include:
– Smoky/red which indicates present of blood in urine
– Greenish – organe-brown indicates bile pigments which may indicate problems with the liver
– Various colours may be as a result of drugs or other substances which have been ingested.
Bring about turbidity or sediment in urine. Examples of deposits found in urine:
Mucus: In small quantity will appear as very slight haze in large quantity forms gelatinous mass
Pus: Appears as yellowish dense mass which lies at bottom of the urine container. It is the outcome of inflammation of any part of the urinary tract.
Urates: Seen in concentrative acid urine as a white or point deposit. It indicates high acidity of the urine.
Uric Acid: Appears as brownish deposit in concentrated acid urine
Phosphate: In alkaline urine, appears as a whitish-grey deposit
Characteristic odour of urine is like the smell of newly cut grass
Presence of acetone gives a sweet smell
Infection of the urinary tract e.g. E. coli infection gives urine a fishy smell
Variable – an average adult may pass between 1200 – 1500 millimeter of urine in 24 hours.
Acid urine changes blue litmus paper to red
Alkaline urine turns red litmus paper to blue
This is the ratio between the weight of a given volume of urine and the weight of an equal volume of distilled water at room temperature 260C. This varies with the nature and quantity with the nature and quantity of food eaten as well as the quantity of water and other fluid taken.
Specific gravity is measured with a urinometer which is calibrated in distilled water it reads 1,000. Average specific gravity of urine is 1.010 – 1.025.
POINTS TO NOTE WHILE MEASURING THE SPECIFIC GRAVITY OF URINE
Tray with the following
Test for reaction with blue and red litmus paper, acid turns blue to red.
Alkaline red to blue and neutral they remain the same.
For chemical test, urine will be made acid, test for specific gravity.
TEST FOR PROTEIN
– 2 cold tests
– 1 hot test
NB: If test is positive, filter urine and test again.
The specific gravity is very essential here. It should be diluted if between1010 to 1020 with an equal amount of water. If above 1020, dilute with twice the amount of water and double or triple the result.
ESBACH’S QUANTITATIVE TEST
Esbach’s urinometer should be used. If urine is cloudy it should be filtered.
Pour urine up to the letter “U” on the tube and esbach (esbach’s reagent poured up to the letter “R”). Cover with rubber cork.
The tube is inverted a few times label with the client name, bed number, time and date of collection and whether diluted or not.
Thenplace in a wooden container allow to stand for 24 hours without disturbance.
The level of any white precipitate formed in the graduated tube shows the amount of protein in grammes per liter ofurine.
TEST FOR ACETONE IN URINE
b Place one drop of urine on the tablet
c.. Leave for 30 seconds
d.. Compare any colour change with colour scale
If a + (plus) of acetone – light purple
Deep purple = ++
TEST FOR BLOOD IN URINE
BILILABSTIX: Used for testing of pH, Glucose, Protein, Ketone and blood and bile in urine.
Dip the test end into the urine and leave for 30 seconds see instructions on the bottle.
PROCEDURE FOR THE BILE TEST
Five milliliters (5ml) of urine is poured in each of the 5 test tube.
Few drops of tincture of iodine is added, drop by drop to one of them
Shake the test tube with urine and iodine gently
Compare it with the other test tube. If a green colour develops bile is present.
TEST FOR BILE SALT
Add a pinch of flower of sulphur on top of urine in a specimen glass. If bile salt is present the flower of sulphur will sink to the bottom of the specimen glass. Or pour urine into a test tube, cork with your thumb and shake vigorously. A yellow froth denotes the presence of bile.
HEMACOMBISTIX for testing the presence of Glucose, Protein, and blood in urine.
Deep the strip in the urine. For strip reads immediately for Glucose read after 10 seconds. Protein may be read immediately. For blood read at 30 seconds. See instructions on the bottle.
OTHER TEST FOR BLOOD in URINE MADE BY THE NURSE IN THE WARD
To an inch of urine add 2 drops of guacum. Run ozonic ether doion solution the side of the tube to form a layer on top.
If blood is present a blue ring develops at the junction of the two fluids
NB: This is a method that is not often used now because of the different reagents strips.
Other reagent sticks used in urine testing for various tests include:
– Combi 6,
– Combi 9 and;
NOTE: Several types of urine specimen are obtained: a clean specimen, a mid stream specimen (also called a clean catch), a catherized specimen and urinary drainage system.
TEST FOR PUS IN URINE
Add hydrogen peroxide to some urine in a test tube.
RESULT: If pus is present frothing will occur.
Microscoping examination in the laboratory is the best test for pus.
Test for chloride in urine:
– Wash test tube and rinse with distilled water.
– Add 10 drops of urine into the test tube
– Rinse the dropper with distilled water
– Add a drop of 20% potassium chromate
– Rinse the dropper
– Add silver nitrate, 1 drop at a time
– Shake the test tube between drops
– Continue to add silver nitrate 1 drop at a time till sharp colour changesfrom yellow to reddish-brown.
– The number of drops of silver nitrate indicates the number of grammes of sodium chloride per litre of urine.