Routine Chemical Examination of Urine Flashcards
Routine Chemical Examination of Urine includes what observation of 3 components?
- pH
- Protein
- Glucose
Plastic strip that contains one or more chemical-impregnated absorbent pads
AKA dipstick
Reagent Strip
Familiarize the Reagent Strip Testing Procedure
- Mix the specimen
- Insert reagent strip
- Remove excess urine
- Time according to manufacturer’s directions
- Compare reaction colors with the manufacturer’s chart under a good light source
- Perform backup tests when indicated
- Be alert for the presence of interfering substances
- Understand the principles and significance of the rest; read package inserts
- Relate chemical findings to each other and to the physical and microscopic urinalysis results
Reagent Strip Testing Procedure
refrigerated specimens to reach what temp prior to testing ?
Room temperature
Reagent Strip Testing Procedure
For how many seconds should the reagent strip be dipped?
1 sec
Reagent Strip Testing Procedure
How should the reagent strip be dipped?
complete but briefly
Reagent Strip Testing Procedure
How to remove excess urine in reagent strip?
- Run edge of strip along rim of tube
- Blot edge on absorbent paper
Reagent Strip Testing Procedure
For how many seconds should you wait to read glucose after dipping reagent strip into urine?
30 seconds
Reagent Strip Testing Procedure
From what direction do you read the reagent strip?
Bottom to top
Reagent Strip Testing Procedure
Do you read glucose or leukocytes first? why?
Glucose becasue it reacts rapidly
T or F
Reading leukocytes first causes false positive results for glucose
F (false negative results)
Reagent Strip Testing Procedure
After waiting for the reagents to react with the strip, what should you do?
Compare reaction colors with the manufacturer’s chart under a good light source
Reagent Strip Testing Procedure
In comparing reaction color’s with manufacturer’s chart, in whwat direction should you hold the strip?
Horizontally close to the color chart (not touching)
T or F
Holding the reagent strip close to the manufacturer’s bottle to the point of contact should not be done since it results to contamination
T
Reagent Strip Testing Procedure
Where you will insert the strip then operate on for the machine to read it to you
Reagent strip reader
T or F
the MT should always perform backup test when indicated
T
Reagent Strip Testing Procedure
Backup test for glucose
Benedict’s test
Reagent Strip Testing Procedure
Backup test for protein
heat and acetic acid or 3% Sulfosalicylic acid TEST (Exton’s)
T or F
One should be alert for the presence of interfering substances
T duh
Reagent Strip Testing Procedure
You understand the principle and significance of the test by?
reading package inserts
Reagent Strip Testing Procedure
Relate ………. to each other and to the ………. ………….and ………… urinalysis results
pretend the period are blanks, di ko mapalce maayos yung blanks
Relate chemical findings to each other and to the** physical** and microscopic urinalysis results
T or F
Relating physical and miscroscopic results means that once color of urine is red, microscopically there should be RBC present
T
Care of Reagent Strips
How should reagent strips be stored?
- Store with desiccant in opaque tightly capped containers
- Store below 30 c
- Keep strips in original container
- Remove immediately prior to use
Care of Reagent Strips
Presence of air in reagent strips cause?
discoloration
Care of Reagent Strips
Where should the reagent strips be stored? at what temperature?
- with desiccant in opaque tightly capped containers
- below 30 c
Care of Reagent Strips
Do not expose the strips to?
volatile fumes
Care of Reagent Strips
Do not touch the ?
test areas
Care of Reagent Strips
Do not use if the chemical pads become?
discolored
T or F
One should remain to use if chemical pads become discolored
F (one should discard)
Care of Reagent Strips
The reagent in the strip that is usually the first one to be discolored
Urobilinogen
T or F
Do not use past the expiration date
T.
Care of Reagent Strips
Do not transfer test strips to ?
another vial
T or F
Touch the test zones with your fingers
F (DO NOT touch test zones with your fingers; hold bottom without test)
What are the 4 sources of error
- Unmixed specimen
- Strip in urine for extended period
- Excess urine in the strip
- Refrigerated specimen
Sources of error
These 2 tests are usually affected by unmixed specimen
RBCs and WBCs
T or F
Unmixed specimen cause RBCs and WBCs to precipitate at bottom of container which causes false (+) results
F (cause false negative result)
Sources of error
reagents will leech (lalabas), goes into the urine → no reagent in test pad
Strip in urine for extended period
Sources of Error
What is the required component in a reagent strip which is a test fro protein that acts as a buffer
Citric acid
Sources of Error
No citric acid causes what result?
False positive result
Sources of Error
Run-over between chemicals producing distortion of colors
Excess urine in the strip
Sources of Error
What should be done to avoid excess urine in the strip ?
- Blot edge of the strip
Sources of Error
Refrigerated specimen cause what results?
False negative results
since enzymes do not react at cold temp.
Do enzymes thrive in cold or hot environment?
hot environment; do not react in cold temperature
T or F
Glucose gives false negative results once strip is subjected to cold temperature
T
Familiarize Quality Control for Routine Chemistry
- Test open bottles of reagent strips with known positive and negative controls every 24 hours
- Resolve control results that are out of range by further testing
- Test reagents used in backup tests with positive and negative controls
- Perform positive and negative controls on new reagents and newly opened bottles of reagent strips
- Record all control results and reagent lot numbers
Quality control
Test open bottles of reagent strips using what method?
positive and negative controls
Quality Control
How often should one test open bottles of reagent strips with known positive and negative controls?
every 24 hours (once daily)
Quality control
What should one do when control results are out of range ?
Resolve by further testing or repeating it
Quality control
What are the following that should be tested for positive and negative control?
- Open bottle of reagent strip
- Test reagents in backup test
- New and newly opened bottles of reagent strips
Quality Control; T or F
one should record only the control results of the newly opened bottles
F (all control results and their reagent lot numbers)
Quality Control
What 2 things should be recorded?
All control results and reagent lot numbers
If you see this card, study the procedure for quality control of reagent strips
go
Test using different reagents or methodologies to detect the same substances as detected by the reagent strips
Confirmatory Test
Confirmatory Test
To what products are confirmatory tests done?
Tablets and liquid chemicals
Confirmatory Test
reflects the ability of the kidney to maintain normal hydrogen ion concentration in plasma and extracellular fluid
pH
pH; T or F
Secretion of H+ ions in urine hekp maintain acid-base balance in the body
T
pH
must buffer and eliminate excess acids
Blood
Buffering capacity of blood depends on?
bicarbonate ions (HCO3)
Secretion of hydrogen ions causes reabsorption of?
bicarbonates
acidosis, normal, alkalosis?
pH of 7.40
Normal
acidosis, normal, alkalosis
pH of 7.00
acidosis
acidosis, normal, alkalosis
8.75
alkalosis
pH range of a first morning specimen
5.0 – 6.0
pH range of a random specimen
4.5 – 8.0
pH of an after meal specimen
Alkaline
Familiarize the factors which could affect urine pH
- Acid base content of the blood
- Patient’s renal function
- UTI
- Patient’s dietary intake
- Age of the specimen
factors which could affect urine pH
What is the effect of UTI in urine?
increases alkalinity
factors which could affect urine pH
What is the effect of old age of specimen?
specimen becomes alkaline
Familiarize the Clinical Significance of urine pH
- Respiratory or metabolic acidosis
- Respiratory or metabolic alkalosis
- Defects in renal tubular secretion and reabsorption of acids and bases (renal tubular acidosis)
- Precipitation of crystals and calculi formation
- Treatment of UTI
- Determination of unsatisfactory specimen
Clinical Significance of urine pH
happens when lungs are unable remove enough CO2, leads to too much CO2 in body
metabolic acidosis
Clinical Significance of urine pH
Too much CO2 causes pH to become?
acidic
Clinical Significance of urine pH
Low CO2
metabolic alkalosis
Clinical Significance of urine pH
Tubules unable to reabsorb bicarbonates
Defects in renal tubular secretion and reabsorption of acids and bases (renal tubular acidosis)
Clinical Significance of urine pH
What happens if tubules cannot reabsorb bicarbonates?
goes into urine and will not secrete H+
Clinical Significance of urine pH
Precipitation of crystals and calculi formation depends on?
pH
Clinical Significance of urine pH
Crystals come from precipitation of what?
precipitation of inorganic chemicals
Clinical Significance of urine pH
What happens if crystals are not flushed out
it turns into stones
Clinical Significance of urine pH
most frequent constituent of renal calculi
Calcium oxalate
Clinical Significance of urine pH
In what pH of urine does the calcium oxalate precipitate?
acidic urine
Clinical Significance of urine pH
Since calcium oxalate precipitate in acidic urine, what do the physicians do in order to idscourage formation of calculi?
they alkalinize it
Clinical Significance of urine pH
pH which indicates specimen is already stale?
9.0
Clinical Significance of urine pH; T or F
Specimen should be recollected if it has pH of 9.0
T (stale already)
Acid or Alkaline Urine?
Increased protein and meat diet
Acid Urine
Acid or Alkaline Urine?
Cranberries
Acid Urine
Acid or Alkaline Urine?
Acid producing bacteria
Acid Urine
Acid or Alkaline Urine?
Starvation
Acid Urine
Acid or Alkaline Urine?
Dehydration
Acid Urine
Acid or Alkaline Urine?
Diarrhea
Acid Urine
Acid or Alkaline Urine?
Diabetes mellitus
Acid Urine
Acid or Alkaline Urine?
Increased fruits and vegetables
Alkaline Urine
Acid or Alkaline Urine?
Citrus
Alkaline Urine
Acid or Alkaline Urine?
after meal
Alkaline Urine
Acid or Alkaline Urine?
Renal tubular acidosis
Alkaline Urine
Acid or Alkaline Urine?
Urease producing bacteria
Alkaline Urine
Acid or Alkaline Urine?
Hyperventilation
Alkaline Urine
rabid release of carbon dioxide
Acid or Alkaline Urine?
Old specimen
Alkaline Urine
used as home remedy for urine
Cranberries
the common of these 4 are the formation of ketone bodies (presence of acid substances)
- Starvation
- Dehydration
- Diarrhea
- Diabetes mellitus
T or F
Hyperventilation causes rabid reabsorption of carbon dioxide hence produces acid urine
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F (opposite, hyperventilation is rabid release of CO2 hence alkaline urine)
What are the methods used to measure pH?
- pH strip
- pH electrode
- Titratable acidity
Methods of Measuring pH
- Double indicator system
pH reagent strip
Methods of Measuring pH
Indicators used in pH reagent strip
Methyl red & Bromothymol blue
Methods of Measuring pH
Principle of pH Reagent strip
Double indicator system
Methods of Measuring pH
Methyl red changes color from? also what pH range
red to yellow
pH 4-6
Methods of Measuring pH
Bromothymol blue changes from what color? also what pH
yellow to blue
pH 6-9
Methods of Measuring pH
In reagent strips, what pH does correspond to color orange?
5.0
Methods of Measuring pH
In reagent strips, what pH does correspond to color blue
8.5
Methods of Measuring pH
What is the color transition in reagent strip?
5.0 orange → green → blue (8.5) as pH ↑
Methods of Measuring pH
Reagent strips should be read after?
after 60 seconds
Methods of Measuring pH
- pH meter w/ glass electrode
- Measures the voltage caused by the H+ ions in the urine
- An electrode is dipped into the solutions
pH electrode
Methods of Measuring pH
Measured by titrating an aliquot of 24 hour urine with 0.1 N NaOH with pH 7.4 as an end point
Titratable Acidity
Methods of Measuring pH
What urine specimen is used in titratable acidity?
24 hour urine specimen
Methods of Measuring pH
In titratable acidity, what other substance are used with 24 hour urine?
0.1 N NaOH
Methods of Measuring pH
In titratable acidity, what is the pH end point?
pH 7.4
Important renal marker
Protein
Volume of clinical proteinuria?
> 30 mg/dl
T or F
Most of the albumin is not filtered
T
Filtered albumin is reabsorbed or excreted?
reabsorbed by tubule
Normal amount of protein in the body per day?
less than 100 mg of protein / 24 hours (150 from henry)
or
less than
10 mg/dl average random
According to henry’s and bishop, what is the molecular weight of protein allowed by glomerulus to filter?
Henry: < 70,000 mw
Bishop: < 66,000 mw
What are the other proteins in urine?
- Microglobulin
- Uromoduli
Other proteins in urine
What is the other name of uromodulin?
Tamm-Horsfall glycoprotein
Other proteins in urine
- Tamm-Horsfall glycoprotein
- lines matrix of all casts
Uromodulin
How many g/day is the protein content for functional proteinuria?
0.5 g/day
- 0.5 g/day
- This is usually resolved with rest for 2-3 days
Functional Proteinuria
How many days should one rest to resolved functional proteinuria
2-3 days
repeat collection after
Familiarize the causes of functional proteinuria
- Dehydration
- Exercise
- Congestive Heart Failure
- Cold exposure (prolonged cold baths)
- Fever
- Late pregnancy
- Emotional stress
- Exaggerated Lordotic posture * (Exaggerated lumbar curve)*
- Happens when patient is standing
Postural/Orthostatic
Positive or negative in urine protein?
Day
positive
Positive or negative in urine protein?
Night
negative
Positive or negative in urine protein?
Vertical positioning of the body
positive
Positive or negative in urine protein?
Horizontal positioning of the body
negative
Positive or negative in urine protein?
First voided urine
negative
Positive or negative in urine protein?
2 hrs standing or walking
positive
Familiarize the procedure in collecting sample postural/orthostatic
- Let patient urinate before bedtime and get sample
- Patient sleeps horizontally
- Upon waking up, patient will be asked to urinate and test
- Ask patient to stand up and walk, after 2 hours collect urine sample and test again
- Comapre samples
Urine is contaminated directly or indirectly with albuminous fluids, pus cells, blood, vaginal discharge
Accidental or False or Pseudo
In Accidental or False or Pseudo, what are the constituents which directly or indirectly contaminate urine?
albuminous fluids, pus cells, blood, vaginal discharge
Example of Accidental or False or Pseudo
vaginitis, cystitis
T or F
Pathologic proteinuria are renal diseases and indicated decreased permeability of the glomerular filter
F (indicated increased permeability of the glomerular filter)
Quantification proteinuria
How many g/day is the amount of protein in heavy proteinuria?
> 4g per day
Quantification proteinuria
How many g/day is the amount of protein in moderate proteinuria?
1 to 4 g/day
Quantification proteinuria
How many g/day is the amount of protein in minimal proteinuria?
<1 g/day
Quantification proteinuria
Syndrome associated with heavy proteinuria
Nephrotic syndrome
Yes or No
Is this correlated with nephrotic syndrome?
↑ serum albumin
No, should be ↓ serum albumin
Yes or No
Is this correlated with nephrotic syndrome?
↑ Lipid in blood & urine
Yes
Yes or No
Is this correlated with nephrotic syndrome?
Granular cast
Yes
Yes or No
Is this correlated with nephrotic syndrome?
Glycogen cast
No, should be Fatty cast
Yes or No
Is this correlated with nephrotic syndrome?
Oval fat body
Yes
Quantification proteinuria
What are the conditions correlated with nephrotic syndrome?
- ↓ serum albumin
- ↑ Lipid in blood & urine
- Granular cast
- Fatty cast
- Oval fat body
T or F
Heavy proteinuria means there is high amount of protein in urine and low in blood
T