URINALYSIS PROCEDURES Flashcards
What is an important screening test to test and asses:
- Renal function/disorder
- Endocrine or Metabolic function/disorder
- UTI
- Systemic diseases
Urinalysis
What is a cost effective in-vitro diagnostic test that is simple to perform?
Urinalysis
What method of urine collection are these?
- First morning void
- Random urine specimen
- Clean catch urine specimen
- 24-hour urine specimen
Non-instrumented collection
What method of urine collection are these?
- Urethral catheteration
- Suprapubic Needle Aspiration
- Catheterization and Bladder irrigation
Instrumented collection
How quickly should urine specimens be analyzed?
Fresh, preferably within 1-2 hours
If unable to test the urine specimen at the time of delivery, how long can you refrigerate the specimen after collection?
3-6 hours
What happens if a urine specimen is left at room temperature?
It will begin to decompose and deliver inaccurate results
What is the reason for the decomposition of urine specimens left at room temperature?
Presence of bacteria
What produces ammonia and then combines with hydrogen ions to increase the pH of urine?
Urea splitting bacteria
True or False
If glucose is present, the bacteria may use it as a source of energy resulting in false negative glycosuria.
True
True or False
Certain urinary elements, such as blood cells and casts, will deteriorate if left standing without any kind of preservative.
True
What method of Non-instrumented collection is this?
- Most concentrated
- Increase number of abnormal elements
- Decreased deterioration of formed elements
- Recommended specimen for chemical and microscopic examination
First morning void
What method of Non-instrumented collection is this?
- Collected anytime
- Most convenient and most common
- Can detect abnormalities but not as sensitive as first morning void
Random urine specimen
What method of Non-instrumented collection is this?
- Specimen of choice for bacterial cultures
a. may perform cultures within 12 hours after collection, only if specimen was refrigerated
b. genitalia must be cleaned with mild antiseptic solution
c. collect midstream in a sterile container
Clean catch urine specimen
What method of Non-instrumented collection is this?
- Gives quantitative results
- preservatives may be needed
24-hour urine specimen
What method of Instrumented collection is this?
- Not recommended for bacteriological examination
- Use only if no other way to collect urine
- Commonly used on marked obese patient with difficulty in urine collection
Urethral Catheterization
What method of Instrumented collection is this?
- In place of catheterization for obtaining a single urine sample
- inserting the needle directly into the distended bladder
- avoids vaginal and urethral contamination
- performed for bladder outlet obstruction (urinary retention)
Suprapubic Needle Aspiration
What method of Instrumented collection is this?
- Utilizes vigorous transcatheter agitation of the bladder
a. 50-72 ml saline inserted into the bladder
b. bladder content is then removed for cytologic study - This method yields optimum cellular sample of bladder epithelium
- Urine sample analysis
a. physical
b. chemical
c. microscopic
Catherization and Bladder irrigation
What is the normal urine volume in a 24 hour period?
600-2000ml
What is the average urine amount daily?
1500ml
What is directly related to urine output?
- Fluid intake
- Temperature and climate
- Amount of perspiration that occurs
What does the color of urine depend on?
pigment (urochrome) concentration
What is the normal color of urine?
straw (light yellow) to dark amber
True or False
Ingested foods or medications don’t affect urine color
False
Urine color may vary because of ingested foods or medications
A blue-green urine color may suggest what?
methylene blue
used as a dye or stain in diagnostic procedures
A dark orange urine color would suggest what?
Pyridium
used for UTI infections
A milky white urine color would suggest what?
Caused by chyle
An olive green to brown/black urine color would suggest what?
Phenols
poisonous compound used for antimicrobial agent
A yellow to brown (turning greenish with foam when shaken) urine color suggests what?
presence of bile
A red or red-brown urine color would suggest the presence of what?
blood
Turbid Alkaline urine is due to what?
- Amorphous phosphate
2. Amorphous carbonate
Turbid acidic urine is due to what?
- Amorphous urates
2. a pinkish turbidity frequently indicates the presence of urates
True or False
Normal urine has a characteristic odor due to volatile acids
True
Urine that has been standing for a long time develops what kind of smell due to the breakdown of urea by bacteria?
ammonia
True or False
The odor of urine is considered very diagnostically important
False
A sweet or fruity smell to urine is an indicator for what?
Ketones
A pungent smell with urine is usually due to what?
ammonia produced by bacteria
A maple syrup smell to urine would indicate what?
“Maple syrup urine disease” a congenital metabolic disorder
A sweaty feet smell to urine is indicative of what?
Isovaleric acidemia, presence of butyric or hexanoic acid in urine
What is the specific gravity for Random Urine?
1.003-1.035
What is the specific gravity of 24-hour Urine?
1.015-1.025
True or False
Normal urine is negative for glucose
True
The quantity of glucose in the urine is dependent on what?
- Blood glucose level
- Rate of glomerular filtration
- Degree of tubular reabsorption
What will appear in the urine once the threshold level of 160-180mg/dL in the blood is exceeded?
Glucosuria
The presence of glucose in the urine may indicate what disease?
May indicate diabetes mellitus or any other conditions that cause hyperglycemia
True or False
Normal urine is positive for ketones
False
What is the presence of ketones in the urine as a result of incomplete fatty acid utilization?
Ketonuria
Can the presence of ketones in the urine indicate Diabetes Mellitus ?
Yes
What is known as an increased ketone level in blood and urine?
Ketosis
Ketosis is found in conditions associated with what?
- Decreased carbohydrate intake (starvation)
- Decreased utilization of carbohydrates (diabetes mellitus)
- Digestive disturbances or dietary imbalance (high fat diet, low carbohydrate diet)
- Eclampsia
- Prolonged vomiting
- Diarrhea
Is normal urine negative for occult blood?
Duh
The presence of blood in the urine can cause the sample to appear what?
red and “smoky”
The presence of blood in the urine is referred to as what?
Hematuria
Intact RBC’s present in the urine may indicate what?
Damage/trauma to the kidney or urinary tract
Intact RBC’s present in the urine may indicate renal diseases such as what?
- Glomerulonephritis
- Malignant hypertension
- Polycystic kidney disease
Is normal urine usually negative for bilirubin?
Yes
Any condition that causes jaundice will result in the appearance of what in the urine?
Bilirubin
Bilirubinuria indicates what?
- Hepatocellular disease
2. Intra or extra-hepatic biliary obstruction
What is the normal concentration for Urobilinogen in the urine?
1 EU or less
True or False
Small urobilinogen amounts up to 1mg/dL is normal
True
An increase in urobilinogen is indicative of what?
liver disease and hemolytic disease
What is the pH range for urine and what is the average?
- Range: 4.6 - 8.0
- Average: 6.0
usually slightly acidic
These are pathological conditions that can cause what?
- Respiratory and metabolic acidosis
- UTI by E. Coli
- Uremia
- Severe Diarrhea
- Starvation
Acidic Urine
These are pathological conditions that can cause what?
- UTI’s caused by Proteus and Pseudomonas species
- Respiratory and metabolic alkalosis
Alkaline urine
Is normal urine negative for protein?
Yes
What is an important indicator for renal disease?
Protein in the urine
Proteinuria mainly occurs by two mechanisms, what are they?
- Glomerular damage
2. Defect in the reabsorption process of the tubules
What are associated diseases due to proteinuria?
- Minimal Proteinuria
- Moderate Proteinuria
- Severe Proteinuria
What are these associated with?
- Polycystic kidneys
- Chronic pyelonephritis
- Inactive chronic glomerulonephritis
- Benign orthostatic proteinuria
Minimal proteinuria (<0.5 g/Day)
What are these associated with?
- Nephrosclerosis.
- Tubular interstitial disease.
- Preeclampsia.
- Multiple myeloma.
- D diabetes nephropathy.
- Malignant hypertension.
- Pyelonephritis with hypertension.
- Toxic nephropathies.
Moderate proteinuria (0.5-3.5 g/day)
What are these associated with?
- Glomerulonephritis.
- Lupus nephritis.
- Amyloid disease.
- Lipoid nephrosis.
- Intercapillary Glomerulosclerosis.
- Severe venous congestion of the kidney.
Severe proteinuria (>3.5 g/day)
Is normal urine negative for nitrites?
Yes
What is formed by the breakdown of nitrates by organisms that cause UTI’s (E. Coli)
Nitrite
What is the presence of bacteria in urine, indicative of UTI?
Bacteriuria
True or False
Esterase is an enzyme
True
True or False
Normal urine is negative for Leukocyte Esterase, which detects esterase released by neutrophils in the urine
True
What is an indirect test for bacteriuria ?
Leukocyte Esterase
What is associated with an inflammatory process in or around the urinary tract?
(UTI, acute glomerulonephritis)
Leukocyturia
What is a common clinical tool for the evaluation of various renal and nonrenal problems?
UA
What lab consist of a macroscopic analysis (appearance), chemical analysis (dip stick) and a microscopic analysis looking for formed elements?
UA
In a normal UA what are the results for the following?
- Color
- Leukocyte esterase
- Nitrite
- Urobilinogen
- Color - clear to yellow
- Leukocyte esterase - Negative
- Nitrite - Negative
- Urobilinogen - < or equal to 1.0 mg/dL
In a normal UA what are the results for the following?
- Protein
- pH
- Blood
- Specific gravity
- Protein - negative to trace
- pH - 4.6 to 8.0
- Blood - negative
- Specific gravity - 1.003-1.035
In a normal UA what are the results for the following?
- Ketones
- Bilirubin
- Glucose
- RBC
- Ketones - negative
- Bilirubin - Negative
- Glucose - Negative
12 RBC - 0-3 HPF (high power field)
In a normal UA what are the results for the following?
- WBC
- Epithelial Cells
- Casts
- Bacteria
- WBC - 0-2 HPF
- Epithelial Cells - 0-1 HPF
- Casts - Depends on the type
- Bacteria - Negative to trace
What are some critical values with a UA?
- Strong positive test for glucose and ketones
- Glucose on urine dipstick >1000 mg/dL with small, medium, or large ketones
- Urine colony count >50,000 colonies/mL if a single organism
A healthy adult may excrete very small amounts of protein a day, about how much is that?
10-100mg
Clinical proteinuria is defined as the loss of how much protein a day?
> 500mg/day
These are all causes of what?
- HTN
- Lower UTI
- Fever
- Exercise
Mild proteinuria <0.5g/day
These are all causes of what?
- CHF
- Chronic glomerulonephritis
- Acute glomerulonephritis
- Diabetic nephropathy
- Pyelonephritis
Moderate proteinuria 0.5-3 g/day
These are all causes for what?
- Amyloid
- Chronic glomerulonephritis (severe)
- Diabetic nephropathy
- Lupus nephritis
Significant proteinuria > 3 g/day
A persistent pH in the urine greater than 7.0 is associated with what?
calcium carbonate, calcium phosphate and magnesium-ammonium phosphate stones
A pH in the urine below 5.5 is associated with what kind of stones?
cystine and uric acid stones
Is urobilinogen normally present?
yes
An increase in what may be the result of hemolytic anemia, cirrhosis, or viral hepatitis?
Urobilinogen
Urobilinogen is absent in what?
Total biliary obstructions
A dark yellow or greenish brown color of urine generally suggests bilirubin in
the urine seen in patients with what?
Obstructions of the bile duct
Dipsticks for testing blood in urine are dependent on the presence of what?
- RBC’s
- Hemoglobin
- Myoglobin
A dipstick can detect as few as how many RBC’s HPF?
1-2 RBC’s HPF
True or False
All positive dipsticks require further evaluations
True
True or False
The presence of >3 RBCs HPF is considered normal
False
Persistent RBCs in the urine may be indicative of what?
- Glomerulonephritis
- Kidney stones
- Cancer
- Infection
Myoglobin may also lead to a false positive with dipsticks and is highly suggestive of what?
Rhabdomyolysis
Many dipsticks can detect the presence of leukocyte esterase in urine and give a semi-quantities estimate of pyuria, thus can be considered an indirect test for what?
UTIs
Potentially significant pyuria is defined as what?
3> WBCs HPF
What indicates bacterial infection, due to breakdown of nitrates to nitrites by the bacteria?
Nitrite
The presence of nitrite in the urine is another indirect indicator of what?
UTI
Although glucose is filtered in the kidneys it is almost completely reabsorbed in the proximal tubule so that glucose is generally absent in urine. However when glucose reaches a level of _____ in the blood, the ability to reabsorb is exceeded
180mg/dL
Glycosuria is suggestive of what?
Diabetes
Ketones and Ketonuria along with glucose in the urine is suggestive of what?
Uncontrolled type 1 diabetes
What should the first consideration be when microorganisms are found in the urine?
Contamination
With epithelial cells in the urine, 1 cell HPF is considered normal, however an increased number of cells may be indicative of what?
Acute tubular necrosis or inflammation as seen in glomerulonephritis.
Phenylketonuria is what?
Mousy urine
What is know as an increased urine output?
Polyuria
What is known as a decreased urine volume?
Oliguria
What is known as no urine output?
Anuria