URINALYSIS

URINALYSIS

It is the routine examination done on urine in a laboratory.

Urinalysis

TEST	NORMAL	ABNORMAL
Volume	1 to 1.5L/day	Oliguria :<400ml day="" o:p="">

Anuria <100ml day="" o:p="">

Polyuria :>2L/day.

Colour

Amber

Milky white : chyluria

Red :Haematuria.

Pink:

Haemoglobinuria.

Odour

Ammoniacal

Foul smell in urinary infections.

Clarity

Clear

Turbid in severe proteinuria.

Acid

Alkaline in certain urinary tract infections.

Specific gravity

1010 to 1025

Increased in heavy proteinuria.

Decreased in polyuria.

Fixed at 1010 in chronic renal failure.

Proteins

Not detectable

Present in nephritis , nephrotic syndrome, preeclampsia in women

Glucose

Not detectable

Present in diabetes mellitus.

Ketones

Absent

Present in ketoacidosis

Pus

Absent

Present in pyelonephritis.

Tests on urine

Protein .

1. Heat test : a test tube is filled 2/3 with urine. Its upper 1/3 is heated by holding it tilted over a flame. If that portion becomes turbid as compared to the lower unheated portion, proteins or phosphates are present. If this turbidity disappears on addition of acetic acid, it is due to phosphate. If it does not, it is due to proteins.

2. Nitric acid test:

2ml nitric acid is taken in a test tube. 1ml urine is added to it along the sides of the test tube. If a ring develops at the junction of the two, proteins are present.

3. Albustick test : albustick is dipped into urine. Its colour changes to blackish-green in presence of proteinuria.

GLUSOCE :

1. Benedict’s test :

5 ml of benedict’s qualitative reagent is taken in a test tube and 8 drops of urine are added to it. The mixture is boiled. If it changes colour as shown in the following table, there is glycosuria.

2. Diastick :

The stick is dipped in urine. If it changes its colour as shown on the chart provided with the box of sticks, glycosuria is present.

Interpretation of benedict’s qualitative test

COLOUR		INTERPRETATION
Green	+	0.5%
Yellow	++	1%
Orange	+++	1.5%
Red	++++	2%

Blood

1. Benzidine test is done

2. Haemstick test is convenient . the stick is dipped in urine. If it becomes blue in colour, the test is positive.

CONCENTRATION TEST

The patient is given only 500 ml of water in 24 hours and its specific gravity should not be less than 1025.

WATER EXCREATION TEST :

The patient is asked to pass urine on waking up. Then he is given 1 L water to drink in half an hour. Then he is asked to pass urine every one hour four times.

Volume and specific gravity of each sample are recorded . 800 ml urine should be formed and none of the samples should have the specific gravity more than 1005.

Renal Function Tests:

Blood tests:

1. Blood urea test: Urea is the end product of metabolism of proteins. It is secreted by the kidney. Its blood levels rise if compromised.

2. Serum creatinine: It is secreted by the kidney. Its blood levels rise if renal function is compromised.

Combined blood and Urine tests:

1. Creatinine clearing test: This test needs 24 hours urine and fasting blood. Urinary creatinine and serum creatinine ration is obtained for interpretation of the test.

2. Urea clearance test : It is like creatinine clearance test.

Intravenous pyelography:

A radiopaque dye is injected intravenously. It gets excreted by the kidneys and is passed into the urine. A number of X- ray plates are obtained at specific intervals. This test tells about the structure of the urinary system and the function of the kidneys both.

Cystoscopy:

The inside of the urinary bladder is examined by passing an endoscope through the urethra. It tells about the diseases involving the urinary bladder. It is also useful to pass ureteric catheters into the ureters so that ascending pyelography can be done for studying the inside of the ureters radiographically.