Dipstick urine analysis Flashcards
Overview of Dipstick analysis- why useful, storage, etc
- Different chemical reagents on the strip allow one to perform multiple tests with single urine dip
- Convenient and easy point of care urinalysis
- Compliance with directions is critical to ensure reliability, sensitivity & specificity
- Store reagent strips in original container at room temperature:
- Do not touch testing areas of the reagent strip
- Do not use the reagent strip if any test pad is discolored
- Do not remove desiccant from the bottle
- Replace cap immediately and tightly after removing reagent strip
- Dip test areas in urine completely, but briefly to avoid dissolving reagents off the strip
Keep the strip horizontal after exposing it to the urine
**timing is important!
Dipstick urinalysis color chart
Urine specimen- Leukocytes (LEU)
- “Pyuria”
- Normal range is negative
- Reflects the presence of WBCs that have been broken down to produce leukocyte esterase
- Positive suggests UTI
Urine specimen- Nitrites (NIT)
- “Urinary nitrites”
- Normal range is negative
- Formed by breakdown of urinary nitrates into nitrites
- Nitrate reducing bacteria: (E.coli- Most common, Klebsiella, proteus, staphylococcus, pseudomonas)
- Non-nitrate reducing bacteria
Streptococcus
What is the normal range of leukocytes in urine?
negative
What is the normal range for nirtrites?
negative
What is the normal range of urobilinogen in the urine?
0.2-1.0
small amount
Urine specimen- Urobilinogen (URO)
AKA “Urinary Urobilinogen”
- Normal range is 0.2 – 1.0
- Decreased or absent= Hepatobiliary duct obstruction
- Increased= liver dz, hemolytic dz, excessive exposure of bilirubin to intestinal bacteria
What does an increased urobilinogen indicate?
- Liver disease → inefficient hepatic clearance
- Hemolytic disease → excessive bilirubin production
- Excessive exposure of bilirubin to intestinal bacteria (ex: constipation)
Urine specimen- Protein (PRO)
AKA “Proteinuria”
*Normal range is negative:
- Total protein excretion is <150mg/24hours (<0.15 g/24 hours) is physiologically normal
- Dipstick is highly specific for protein, but insensitive:
<150 mg/day not detected
<300 mg/day may not be detected
Urine specimen- Protein (PRO)–> benign causes or proteinuria
- Dehydration
- Stress
- Pregnancy:
<300 mg/24 hours is physiologic in pregnancy
>300 mg/24 hours is pathologic in pregnancy
- Fever
- Most acute illnesses
- Strenuous exercise
- Vaginal secretions
What are potential serious causes of proteinuria?
- Hypertension (increase in BP= increase in filtration forces in kidney)
- Diabetes (secondary to CKD)
- Glomerular damage (#1 can lead to this)
- Multiple myeloma
Urine specimen- pH
- Normal range is 4.5 – 8.0 with an average of 6.0
- Fluctuates in response to acid-base imbalances → typically fluctuates throughout the day
- pH will increase with UTIs and if the specimen is old
Urine specimen- Blood (BLO)
- “Hematuria”- Gross vs. microscopic
- Normal range is negative
- Is positive, urine is usually cloudy
- RBCs can indicate: UTI, Pyelonephritis, Glomerulonephritis, Renal cancer, Bladder cancer, Strenuous exercise, Menses
what is the normal range of blood in the urine?
negative
Blood specimen in urine: false reading in the setting of excessive muscle breakdown–> myoglobin
Rhabdomyolysis
Trauma (crush injuries, burns)
Myocardial infarction (MI)
how can you determine if the “blood” detected on UA dipstick is truly blood or myoglobin?
microscopic evaluation
Urine specimine- Specific Gravity (SG)
Compares density of urine to density of water (1.000)
Normal range is 1.015 – 1.025
What can an increased (concentrated) specific gravity be from?
Dehydration
Decreased renal blood flow
Glycosuria
Proteinuria
increased specific gravity= concentrated urine
What can a decreased (diluted) specific gravity?
Overhydration
Diabetes insipidus
Chronic renal failure (function is to reabsorb water, if damaged then cant pull water back into body)
Decreased specific gravity= diluted urine
Overview of pathogenesis and pathophysiology of DKA
Urine specimen- Ketones (KET)
“Ketonuria”
Normal range is negative
Product of fat catabolism
Causes of ketonuria
- Diabetic ketoacidosis (DKA)
- Fasting (long periods)
- Starvation
- Vomiting
- Strenuous exercise
- Dehydration
Urine specimen- Bilirubin (BIL)
AKA “Bilirubinuria”
- Normal range is negative
- Urine bilirubin will be conjugated (water-soluble) bilirubin → presence reflects hyperbilirubinemia
- Foam test will be positive
What test will be positive in bilirubinuria?
The foam test
**follow up with LFTS–> if this confirms abnormal bilirubin –> order imaging
Urine specimen- Glucose (GLU)
“Glucosuria” “Glycosuria”
- Normal range is negative
- Seen in urine with serum glucose exceeds the renal glucose threshold of 180 mg/dL
- Renal disorders can lower renal threshold
