Urinalysis Flashcards
1
Q
Urinalysis
A
- Test the characteristic and composition of freshly voided urine
- Screening for disease
- Diagnosis of a suspected condition
- Management and monitoring progress of a condition
2
Q
Characteristics
A
- Colour (Pale to amber Vitamin B supplements can turn urine bright yellow. Some medicines, blackberries, beets, rhubarb, or blood in the urine can turn the urine red-brown)
- By-product of haemoglobin breakdown, urochrome, gives colour
- Affected by concentration, haematuria, diet
- Clarity usually transparent, if cloudy, no fresh, proteinuria, infection, bacteriuria
- Odour - characteristic inoffensive (stronger/offensive if left stagnant or infection present. Sweet if ketones are present)
3
Q
Significance of Composition
A
- 96% Water + 4% Dissolved Substances
~ Urea
~ Uric Acid, Creatinine, Sodium, Potassium, Chlorides, Sulphates, Phosphates
~ Epithelial Cells, Leukocytes - pH of 4.5-8
- pH measures degree of acidity to alkalinity of urine
- Low pH means more acid
4
Q
Specific Gravity
A
- Specific Gravity reflects the kidney’s ability to concentrate or dilute urine
- Want more concentrated urine for accurate testing, best is first morning urine sample
- Low SG means the urine is not concentrated and kidney disease could be present
- High SG could mean the sample is first morning urine, certain drugs may be taken, or dehydration
5
Q
Bilirubin
A
- Bilirubin is a byproduct of the breakdown of haemoglobin
- Urine normally contains no Bilirubin
- Presence may be an indication of liver disease, bile duct obstruction, or hepatitis
- A false positive may result when certain drugs are taken
- A false negative may occur when the sample is exposed to sunlight
6
Q
Blood
A
- Presence of blood in the urine may indicate infection, trauma to the urinary tract, or bleeding in the kidneys
- False positive readings are most often due to contamination with menstrual blood
- A positive result will result in further investigation
7
Q
Glucose
A
- Presence of Glucose (glycosuria not uncommon during pregnancy) indicates that the blood glucose level has exceeded the renal threshold
- Renal threshold lowers in pregnancy
- Useful to screen for diabetes
8
Q
Ketones
A
- Ketones are excreted when the body metabolises fats incompletely (ketonuria)
- May occur due to fasting, vomiting (hyperemesis gravidarum) uncontrolled diabetes
- Some drugs (Captopril) may give a false positive
9
Q
Leukocytes
A
- Leukocytes (white blood cells) usually indicate infection
- Specimen may be contaminated by Leukocytes from another source (Vaginal Discharge)
- When found with nitrates, bacteriuria is strongly suggested
10
Q
Nitrites
A
- Indicative of UTI
- Diet source of Nitrates in urine in presence of Bacteria
- Formed by gram negative bacteria converting urinary nitrate to nitrite
11
Q
Protein
A
- Presence of protein (proteinuria) is an important indicator of renal disease
- Transient positive test usually insignificant due to small amount of albumin and globulin in the urine
- May also result from contamination, vaginal discharge which increases during pregnancy
12
Q
Urobilinogen
A
- Urobilinogen is a degradation product of bilirubin formed by intestinal bacteria
- It may be increased in hepatic disease or haemolytic disease
- Normally present in small amounts
13
Q
Normal Values
A
- Negative results for glucose, ketones, bilirubin, nitrites, leukocyte esterase and blood
- Protein negative or trace
- pH 5-8.0
- Urobilinogen 0.2-1.0 Ehrlich units
14
Q
Handling & Storage
A
- Keep strips in original container
- do not touch reagent pad areas
- Reagents and strips must be stored properly to retain activity
- Protect from moisture
- Store at room temperature
- Use before expiration date
- Lid on tightly
15
Q
Procedure
A
- Dip strip completely into well mixed, room temperature fresh urine sample
- Withdraw strip
- Blot briefly on its side
- Keep the strip flat, read results at the appropriate times by comparing the colour to the appropriate colour on the chart provided
