URINE TESTING
Urine analysis methods comprise testing reaction, specific gravity, albumen, sugar, bile, acetone, pus, blood and yeasts microscopically
Purpose
- To detect reaction, in cystitis the reaction is alkaline
- To detect sugar, it is present in diabetes mellitus
- To detect – protein it is present in kidney damage, pre-eclampsia and is called proteinuria
- To detect acetone, it is present due to incomplete metabolism of fat
- To detect bile – it is seen in cases of obstructive jaundice or hemolytic diseases
- To detect pus cells – it is present due to urinary tract infection
- To detect blood – it is seen in snake bite, fracture pelvis, etc
Characteristics of Normal Urine
- Volume: 1,000 to 2,000 ml in 24 hours
- Appearance: clear
- Odor: aromatic color
- Color: amber or pale straw in color
- Reaction: normal urine is slightly acidic
- Specific gravity: 1.010 to 1.025
- Constituents of the normal urine: water 96 percent, urea 2% and uric acid, urates, creatinine, chlorides, phosphates, sulfates, oxalates – 2%
Characteristics of Abnormal Urine
Volume
- Polyuria – increased in volume
- Oliguria – decreased in volume
- Anuria – total absence or marked decrease of urine
- Suppression – failure of the kidney to secrete urine
Color
- Green or brownish yellow – bile salts and bile pigments
- Reddish brown – urobilinogen
- Bright red – a large amount of fresh blood
- Smokey brown – blood pigment
- Milk white – chyluria due to filariasis
Appearance
- Mucus – appears as a flocculent cloud
- Pus – settles at the bottom as a heavy cloud
- Stones – as fine sand
- Uric acid – as grains of pepper
Odor
- Sweetish or fruity odor – seen in diabetes
Reaction
- Alkaline – cystitis
- Specific gravity
- Diabetes mellitus – increased specific gravity
- Renal disease – low specific gravity
- Constituents of urine
- Kidney damage – albumin
Types of Examination of the Urine
- Physical examination: color appearance, volume, reaction, specific gravity and color
- Chemical examination: routine tests such as for albumin and sugar. Special tests such as tests for acetone, bile pigments and bile salts. Microscopic examination – crystals, casts, RBC, pus cells, epithelial and bacteria
Preliminary Assessment
- The doctor order for any instructions
- Articles available in the unit
- General condition and diagnosis of the patient
- Self-care ability of the patient
Preparation of the Patient and Environment
- Explain the procedure to the patient
- Keep the urine sample ready
- Arrange the articles ready in the treatment
- Provide labeled container for collecting urine
Equipment
- Test tubes 4 to 6 on a test tube
- Test tube holder – 1
- Spirit lamp – 1
- Match box – 1
- Kidney tray with lining to discard the wastes
- Duster or rag piece – to wipe the outside of the test tube before heating
- Acetic acid – to test urine for albumin
- Nitric acid or sulfosalicyclic acid – to test urine for albumin
- Red and blue litmus paper – to test the reaction of the urine
- Urinometer – to measure the specific gravity of the urine
- Benedict’s solution – to test urine for sugar
- Ammonium sulfate crystals, sodium nitroprusside crystals and liquor ammonia to test urine for acetone
- Weak solution of Tr. Iodine to test for bile pigments
- Sulfur powder: to test for bile salts
- Glass jar: to measure the amount of the urine
- Pipette – 2 – to measure drops of urine and reagents
- A small bottle brush – to clean the test tubes
Procedure
Sugar Test
- Take test tube and fix in holder
- Pour 5 ml of Benedict’s solution into test tube
- Light spirit lamp and heat Benedict solution till it boils
- Holding test tube mouth facing away from nurse
- Add 8 drops of urine using dropper and allow boiling for few seconds
- Put off flame and cool test tube under running water
Observations
- Blue: Nil
- Green: +
- Yellow: ++
- Orange: +++
- Brick red: ++++
Albumin Test
A hot test
- Fill 2/3 of test tube with urine, secure test tube holder at very top
- Heat the upper third of test tube over flame
- If there is precipitation, it denotes the presence of wither protein or phosphate
- Add 2-4 drops of 2 percent acetic acid
- If precipitate dissolves it is due to phosphates present in normal urine
- If precipitate does not dissolve it denotes presence of albumin
Observation
- Trace: +
- Cloudy:++ (100mg/dL)
- Thick cloudiness: +++ (500 g/dL)
Cold Test
- Pour a small quantity of nitric acid or sulfosalicylic acid 3 percent in to a clean test tube
- Allow equal quantity of urine to trickle down the sides of the test tube
- If albumin present, a white precipitate will be seen where two fluids meet
Urine pH
- Collect and keep ready with urine sample
- Dip litmus strip in urine and keep for one minute
- Note color change
- Discard strip into container for infected waste
Urine Specific Gravity
- Fill 3/4 of jar with urine
- Gently place urinometer into jar
- When urinometer stops bobbing
- Read specific gravity directly from scale marked on calibrated stem of urinometer
- Make sure that instrument floats freely and does not touch sides of jar
- Read scale at lowest point of meniscus to ensure an accurate reading at eye level
Rothera’s Test (Acetone)
- Take 2 cm depth of ammonium sulfate crystals in a small test tube
- Add equal volume of urine and one crystal of sodium nitroprusside
- Close the test tube with a cork and shake the test tube
- Take liquor ammonia and add it to the urine, trickling through the sides
- Read the results immediately
Observations
If acetone is present permanganate purple colored ring is formed at the junction of urine and ammonia
Hays Test (Bile Salts)
- Take a test tube, half full of urine
- Sprinkle sulfur powder on the surface of the urine
- If the powder sinks down to the test tube, it indicates the presence of bile salts
Smith’s Test (Bile Pigments)
- Fill 3/4 of test tube with urine
- Add iodine drops along the sides of the tube, so as to form a layer on the surface of the urine
- A green color at the junction of the two liquids indicates the presence of bile pigments
After Care
- Discard the urine in the sluice room
- Wash the test tube with soap and water
- Dry the tube, holder and urinometer with jar
- Replace the article after cleaning
- Wash hands thoroughly
Record the procedure in the nurse’s record sheet and dietetic chart
