LAB Part 2 Flashcards
Clinical reasons for performing urinalysis testing
An important indicator of health
What is urinalysis testing used to detect and assess
- Renal function/disorder
- Endocrine or Metabolic function/disorder
- Urinary Tract Infection (UTI)
- Systemic diseases
What is cost-effective in urinalysis testing
In-Vitro diagnostic testing
in-vitro = out of the body
What are the methods of urine collection
Non-instrumented Collection & Instrumented Collection
Name all methods of non-instrumented collection
- First-morning void
- Random urine specimen
- Clean catch urine specimen
- 24-hour urine specimen
Name all methods of instrumented collection
- Urethral catheterization
- Suprapubic needle aspiration
- Catheterization and Bladder irrigation
How soon should urine specimens be analyzed
While fresh, preferably within 1-2 hours
What should be done if the urine specimen is unable to be tested at time of delivery
Refrigerate the specimen 3-6 hours after collection
What happens if urine specimen is left at room temperature
It will begin to decompose and deliver inaccurate results
Explain the mechanism of urine decomposition
- Room temperature urine will decompose due to presence of BACTERIA in the sample.
- Urea splitting bacteria produces ammonia that combines with hydrogen ions to increase pH of urine (changes in pH will dissolve any casts present).
Significance of First-morning void
- Most concentrated (good for HCg)
- Increased abnormal elements
- Decreased deterioration of formed elements
- Recommended specimen for chemical and microscopic examination
Significance of Random urine specimen
- Can be collected anytime*
- Most convenient and most common
- Can detect abnormalities but not as sensitive as FMV
Significance of Clean catch urine specimen
Specimen of choice for bacterial cultures
Significance of 24-hour urine specimen
Gives quantitative results (values)
Who does Instrumented (urine) collection
Providers
Significance of Uretheral Catheterization
- NOT recommended for bacteriological examination
- Commonly used on marked obese patient with difficulty in urine collection or if there is no other way to collect urine
Significance of Suprapubic needle aspiration
- Avoids vaginal/urethral contamination
- Performed for Bladder outlet obstruction (urinary retraction)
- Collection of choice on infants and young children
- Performed to confirm positive cultures from disposable bag AND prior to institution of specific therapy
Significance Catheterization and Bladder Irrigation
- 50-72 mL saline inserted into bladder
- Content removed for cytologies study
Yields optimum cellular sample of bladder epithelium (skin cells)
Urine Sample Analysis is
Physical, Chemical, Microscopic
What are the physical analyses of a urine sample
- Volume
- Color
- Turbidity (clarity)
- Odor
- Specific gravity
What is the normal volume in a 24-hour period range
600-2000 mL
Average is 1500 mL
What is the urine amount directly related to
Fluid intake, temperature and climate, amount of perspiration that occurs
What is the normal color of urine
Straw (light yellow) to dark amber
Meaning of urine being Blue green
Methylene blue (used as a dye or stain in diagnostics procedures)
Meaning of urine being Dark orange
Pyridium (used in UTI)
Meaning of urine being Milky white
Caused by chyle (fat)
Meaning of urine being Olive green to brown black
Phenols (poisonous compound used for anti microbial agents)
Meaning of urine being Yellow to brown (turning greenish with foam when shaken)
Presence of bile (located in the liver)
Meaning of urine being red or red-brown (Smokey appearance)
Presence of blood
What is turbid ALKALINE urine due to
Amorphous phosphate and Amorphous carbonate
What is turbid ACIDIC urine due to
Amorphous urates (pinkish turbidity indicates presence of urates)
Why does normal urine have a characteristic odor
Due to volatile acids
Meaning of urine smelling sweet and/or fruity
Presence of ketones
Pungent smell of urine indicates what
Ammonia produced by bacteria
Meaning of urine smelling like maple syrup
A congenital metabolic disorder (maple syrup urine disease)
usually in infants
Meaning of urine smelling musty and/or mousy
Infant with phenylketonuria
Meaning of urine smelling like sweaty feet
Isovaleric acidemia, presence of buytric or hexanoic acid in urine
What are the specific gravity values
- Random urine: 1.003 - 1.035
- 24-hour urine: 1.015 - 1.025
For chemical analysis, normal urine is negative for what
Negative for:
- Glucose
- Ketones
- Occult blood
- Bilirubin
- Protein
- Nitrite
- Leukocyte esterase (LE)
What is Glucosuria and what is the threshold level
Appears in the urine once the threshold of 160-180 mg/dL in the blood is exceeded
May indicate diabetes Melkite’s or any condition that causes hyperglycemia
What is Ketonuria
Presence of ketones in the urine as a result of incomplete fatty acid utilization
What is Ketosis
An increase of ketones in the blood and urine
What conditions are associated with Ketosis
Starvation (decreased intake of carbs)
Diabetes mellitus (decreased utilization of carbs)
High fat, low carb diets (digestive disturbances or dietary imbalance)
Eclampsia (HTN during pregnancy)
Prolonged vomiting
Diarrhea
Intact RBC’s present in the urine may indicate what
- Damage/trauma to the kidney or urinary tract
- Renal diseases such as: *glomerulonephritis, malignant hypertension, poly cystic kidney disease
- May also be due to menstrual contamination or excercise
*sample may appear red and smokey (blood in urine is hematuria)
What does bilirubin indicate in the urine
Any condition that causes jaundice
Bilirubinuria indicates: Hepatocellular disease, Intra or extra-hepatic biliary obstruction
How does Urobilinogen normally present in the urine
In concentration of 1EU or less
Any increase indicates liver disease and hemolytic disease
What is the range for pH in the urine
4.6 - 8.0
*usually averages around 6.0 (slightly acidic)
What are the pathological conditions that may cause acidic urine
Respiratory and metabolic acidosis
UTI by E. Coli
Uremia
Severe diarrhea
Starvation
What are the pathological conditions that cause alkaline urine
UTIs caused by Proteus and Pseudomonas species
Respiratory and metabolic alkalosis
What does protein in the urine indicate
Renal disease
Proteinuria mainly occurs by what mechanisms
Glomerular damage
Defect in the reabsorption process of the tubules
Associated disease due to minimal proteinuria
<0.5 g/day
Polycystic kidneys
Chronic pyelonephritis
Inactive chronic glomerulonephritis
Benign orthostatic proteinuria
Associated disease due to Moderate proteinuria
0.5-3.5 g/day
Malignant hypertension
Pyelonephritis with hypertension
…. A lot of other ones but not enough to narrow down
Associated disease due to severe proteinuria
> 3.5 g/day
Glomerulonephritis (side note: common thing that keeps popping up)
Lupus nephritis
How is nitrite formed
Formed by breakdown of nitrates by organisms that cause UTIs - E. Coli
What is bacteriuria and what chemical analysis is it a part of
Presence of bacteria in urine, indicative of UTI and is associated with Nitrites
What is esterase
An enzyme
What is leukocyturia
associated with an inflammatory process in or around the urinary tract
UA is a clinical tool for the evaluation of what
Various renal and nonrenal problems
Most UA consist of what
Macroscopic analysis (appearance)
Chemical analysis (dip stick)
Microscopic analysis looking for formed elements
What is the purpose of Rapid Plasma Reagin (RPR)
It is a non-treponemal test for serologic detections of the antibody Reagin
Why is Reagin produced
It is produced in response to an infection of syphilis caused by T. Pallidum (Treponema)
What kind of test is the RPR and what is it mixed with
Screening test/ antigen is mixed with a serum/plasma sample
What does it mean if flocculation is present in the screening test
The test is reactive
What does it mean if there is no flocculation present in the screening test
The test is non-reactive
What is the confirmatory test for RPR testing
Fluorescent treponemal antibody-absorbed test (FTA-ABS)
How are serum sample or plasma sample collected
Collect VENOUS blood in tubes without anticoagulant (Red/SST) for serum and with anticoagulant (Purple top) for plasma
How should serum appear after centrifugation
Serum should be clear and non-hemolyzed to be an acceptable sample
How should RPR be mixed prior to opening the sample
By shaking vigorously for 10-15 seconds
For RPR, test card and controls should be placed on the rotator for how long
8 minutes at 100 revolutions per minute (rpm)
How can you differentiate non-reactive from weakly reactive results
Rotate and tilt card briefly, by hand (3 or 4 to-and fro-motion)
How is RPR exam test card read
MACROSCOPICALLY (seen visually)
How are RPR results read
Reactive or non-reactive
Reactive test results shows flocculation ranging from what
- Slight but definite
- Minimum to moderate
- Marked and Intense
Quality control for RPR is divided into what two sections
Equipment quality control and Reagent quality control
The mechanical rotator is calibrated to what
100 rpm
What is the antigen needle calibrated to
60 drops per 1 mL
What test is used to detect infectious mononucleosis
The Monospot test
What is infectious mononucleosis
A self-limiting disease caused by the Epstein-Barr virus (EBV)
The age group seen with mononucleosis
Seen in young adults and children less than 5 years of age
What is a heterophile antibody
An antibody that is structurally similar to the antibody that is specifically produced as a response to antigen stimulation
For mono, serum samples should be collected how
Collect venous blood in tubes with or without anticoagulant/ after centrifugation, serum or plasma should be clear and non-hemolyzed
The testing procedures for mono
Allow the Latex Reagent and controls to reach room temperature (20 - 30 degrees C)
GENTLY SHAKE (Vigorous shaking should be avoided) vial to disperse and suspend the latex particles in the buffer solution
GENTLY rotate the slide for 3 minutes manually or on a rotator shaker set at 60-100 rpm
How do Monospot test results present
Positive and Negative
Positive results show agglutinations
Negative results demonstrate a smooth, homogenous solution. NO AGGLUTINATION.