3 Flashcards
What is a “dipstick” used for?
Basic diagnostic tool used to determine pathological changes in a patient’s urine in standard urinalysis
How long does it take before you can read a dipstick?
60-120 seconds after the dip
How do the plastic strips (dipstick) testing work?
Plastic strips have pad that contain chemicals that react with certain compounds in the urine producing a specific color. (Paper strips are specific to a single reaction)
For accurate dipstick results, what should you do?
Store reagent strips in their bottle with lid closed at room temperature, this prevents the loss of sensitivity of reagent strips
What should you not expose dipsticks to?
- Sunlight
- Heat
- Cold
- Volatile Substances
- Moisture
When using a dipstick, when should you test urine?
Test urine which is brought to room temperature and well-mixed urine
What would discoloration of the strip indicate?
Significant loss of reactivity
What do the kidneys and lungs regulate?
Acid-base balance of the body
The pH of the urine is a reflection of _____
The ability of the kidneys to maintain normal hydrogen ion concentration in plasma and extracellular fluid
What are the 2 main objectives of urine pH?
1) Diagnostic (e.g. metabolic abnormalities)
2) Therapeutic (e.g. regulation of diet or medications)
What does urine pH normally fluctuate between?
Acidic and Alkaline
Acid indicator =
Methyl Red
Alkaline Indicator =
Bromthymol blue
pH of urine ranges from ______
5.0 to 8.5** in half units (commercial dipstick)
When your protein intake is high, what happens on your urine dipstick?
More phosphates, sulfates are produced which results in more acidic urine
Vegetable diet normally results in urine pH of _____
> 6
What is the large list of factors that result in acidity?
- Dehydration
- Diarrhea
- Fever
- Diabetes Ketoacidosis
- Gout
- Pulmonary Emphysema
- High protein diets or cranberries
- Renal Tubular Acidosis (proximal tubular, distal tubular) metabolic acidosis
- Acidifying drugs (for ammonium magnesium stone prevention)
What is the long list of factors that result in alkalinity (urine)?
- Acute and chronic renal failure
- Urinary tract infections
- Bacterial contamination of urine
- Alkaline drugs
- Diuretics
What is the source of low molecular weight protein that could be found in the urine?
Genito-urinary tract
Describe Mucoprotein Tamm-Horsfall (T-H):**
It is secreted by the renal tubules (renal epithelial cells) and is not derived from blood plasma **
In regards to urine protein, what amount of T-H protein is excreted?**
Less than 150mg/24 hr (or 20mg/dL) **
What is T-H protein?
It is a matrix for formation of calculi or casts
When testing for protein in urine, what is the principle it is based on called?
“Protein Error of pH indicators” ***
What is Protein Error of pH indicators?
Ability of protein to alter the color of some acid-base indicators without altering the pH