URI Ch 1-4
What are some safe activities to do when removing the source of an electric shock?
*Turn off circuit breaker *Use glass container to move instrument *Unplug instrument DO NOT TOUCH THE PERSON BEING SHOCKED
During lab accreditation inspections, procedure manuals are examined for the presence of;
*critical values *procedure references *procedures for specimen preservation
concentration of the tubular filtrate by the countercurrent mechanism depends on all of the following
*high salt concentration in the medulla *water impermeable walls of the ascending loop of Henle *reabsorption of sodium and chloride from the ascending loop of Henle
bicarbonate ions filtered by the glomerulus are returned to the blood;
*in the proximal convoluted tubule *combined with hydrogen ions *by tubular secretion
an advantage to using cystatin c to monitor GFR is;
*it does not require urine collection *it is not secreted by the tubules *it can be measured by immunoassay
What steps are taken when the results of a reagents strip QC are outside the stated confidence limits?
-check expiration date of reagent strip -run a new control -open a new reagent strips container
Advantages of an automated urine analyzer over a manual microscopy are;
-cost effective -centrifugation not required -standardized results
What info is documented when a control is run?
-lot number -expiration date of control -test results
Automated urine particle digital imaging measures
-particle length -particle volume -particle complexity NOT PART DENSITY
Examination variables
-reagent expiration date -constructing a Levy-Jennings chart -calibrating the centrifuge -preventive maintenance -access to manuals
Preexamination variables
-rejecting a contaminated specimen -collecting a timed urine specimen -patient misidentification -wrong test ordered -insufficient urine volume
Post examination variables
-telephoning a positive Clinitest result on a newborn -timely reporting -correcting erroneous results in a timely manner
the specific gravity of the glomerular ultrafiltrate is
1.010
The average daily volume of urine produced by a normal adult is approximately:
1200 mL
After controlled fluid intake, the urine-to-serum osmolarity ratio should be at least
1:1
what is the max length of time a urine specimen can remain unpreserved at room temp before testing
2 hours
a person exhibiting oliguria would have a urine volume of
200 to 500 mL
normal serum osmolarity
270-300 mOsm/L
Urine Output (Polyuria)
3000 mL in 24 hours
The Occupational Exposure to Blood-Borne Pathogens Standard is:
A law enforced by OSHA
Reflectance photometry
A spectrophotometric technique in which light is reflected from the surface of a reaction and used to measure the amount of the analyte.
Lamellar bodies (pulmonary surfactant) are analyzed by
ADVIA 2120i
Reliability
Ability to maintain both precision and accuracy
When combining acid and water what is proper order?
Acid is added to water
Centrifuging an uncapped specimen may produce a bio hazard in the form of:
Aerosols
Which of the following fluids are NOT cleared to be evaluated using XN-Series?
Amniotic
If you observe a red hand rash after removing gloves you should:
Avoid wearing latex gloves in the future
What Urine Chemical Will Deteriorate When Exposed To Light ?
Bilirubin
Formula for creatinine clearance
C=UV/P U=urine creatinine (convert to mL/min) V=urine volume P=serum creatinine **you must convert the time into mins. ex: 2 hrs = 120 mins. so V might be 620 mL for 12 hours (12 hrs = 60 mins) so 620/60 = 10.3 10.3 x V divided by P
What organization publishes guidelines for writing procedures and policies in urinalysis?
CLSI Clinical Laboratory Standards Institute
Name an example of a chemical hazard?
Carcinogen Exposure
Exposure to toxic, carcinogenic, or caustic agents is what type of lab safety hazard?
Chemical
The primary inorganic substance found in urine is
Chloride
The classification of a fire that can be extinguished with water is:
Class A
name a complete automated UA system
Clinitek AUWi Pro System
Which urine elements, if flagged by auto microscopy, would need to be confirmed by manual exam?
Crystals
When a new bottle of QC material is opened, what info is placed on the label?
Date and lab workers initials
patient presenting with polyuria, nocturia, polydipsia, and a low urine specific gravity is exhibiting symptoms of
Diabetes insipidus
What mode of infection transmission can occur through a sneeze?
Droplet
Sodium fluoride used as a preservative for UA bests protects
Drugs
T or F Semiautomated instruments are operator free.
False
The acronym RACE is used during what circumstance and what does it stand for?
Fire Rescue - anyone in immediate danger Alarm - activate fire alarm system Contain - close all doors to affected areas Extinguish/Evacuate - attempt to extinguish the fire or evacuate
Two technologies used for urine sediment analysis
Flow Cytometry and digital imaging
Urinalysis lab personnel should wear coats that are:
Fluid resistant
Employers are required to provide free vaccines for;
HBV
What is the most effective way to break the link in the chain of infection?
Hand washing
What is not an advantage of automated microscopy?
High variation of results
An employee who accidentally spills acid on his arm should immediately:
Hold the arm under running water for 15 minutes
Renal tubular acidosis can be caused by
Inability to produce an acidic urine due to impaired production of ammonia
A color change indicating that a sufficient amount of a patient's specimen or reagents is added correctly to the test system would be an example of;
Internal QC
What should a coefficient of variation be
Less than 5%
In a fully automated analyzer, clarity is measured by
Light scatter
which cells need further intervention when analyzed by automated body fluid instruments?
Malignant cells
The system used by firefighters to assess the risk potential when a fire occurs in a lab is?
NFPA
Clinical osmometers use NaCl as a reference solution because:
NaCl is partially ionized, similar to the composition of urine
What should a firefighter check for before using a water hose on a burning chemical cabinet?
National Fire Protection Association (NFPA) symbol
Are biohazards listed on NFPA?
No
Are reagent strips dipped into urine in fully automated urine chemistry analyzers?
No
Do urine specimen containers need to be disposed of in the biohazard waste container?
No
What should you do if you receive a specimen and requisition form that do not match?
Notify the personnel who collected the specimen
An employer who fails to provide adequate protective gloves can be fined by:
OSHA
a 1st morning specimen is frequently requested to confirm
Orthostatic proteinuria
Acceptable method for disposing of urine specimens?
Pouring down the sink followed by copious amounts of water
Obtaining the same result after testing the same specimens three times is called test:
Precision
Who should NOT work with radioisotopes?
Pregnant women
the testing of a specimen from an outside agency and the comparison of results with participating labs in called;
Proficiency testing
What does PASS stand for?
Pull, Aim, Squeeze, Sweep The operation of a fire extinguisher
which urine sediment particles cannot be autovalidated but will be flagged and must be reviewed by laboratory personnel?
RTE's renal tubular epithelial cells
Lab personnel wear special monitoring badges when working with what hazard?
Radioactive
principle commonly used to measure the concentration of a particular analyte in the chemical examination of urine
Reflectance photometry
Lab equipment and other inanimate objects serve as what in the chain of infection?
Reservoirs
One can learn the carcinogenic potential of potassium chloride by consulting:
Safety Data Sheet
An acceptable disinfectant for the decontamination of blood and body fluids is:
Sodium hypochlorite
In the urinalysis lab, the primary source in the chain of infection would be:
Specimens
Which guideline states lab personnel should consider all patients as possible carriers of blood borne pathogens?
Standard precautions
The Globally Harmonized System is:
The handling and use of hazardous chemicals
T or F Automated urine particle digital imaging measures the total amount of nucleic acid contained within a particle.
True
T or F centrifugation of the urine is needed when using semiautomated analyzers
True
T or F reflectance photometry uses the principle that light reflection from the reagent test pads decreases in proportion to the intensity of the color produced.
True
T or F scattergrams for microscopic analysis use forward scatter, side scatter, and fluorescence
True
The most commonly available fire extinguisher in a hospital is what?
Type ABC
A major advantage of a fully automated analyzer vs. semi is?
Walk away capability
When should one use a plexiglass shield in the lab with urine tube specimens?
When they are uncapped for analysis.
if a substance is completely filtered by the glomerulus and then completely reabsorbed by the tubules the clearance of the substance will be;
Zero
order of blood flow through the nephron
afferent arteriole, efferent arteriole, peritubular capillaries, vasa recta
a patient with oliguria might progress to having
anuria
Water is passively reabsorbed in all parts of the nephron except the:
ascending loop of Henle
Which of the tubules is impermeable to water?
ascending loop of henle
increased turbidity in urine stored at room temperature is usually caused by
bacterial growth
the primary cause of unsatisfactory results in an unpreserved routine specimen not tested for 8 hours is
bacterial growth
If ammonia is not produced by the distal convoluted tubule, the urine pH will be
basic
when will glucose appear in the urine
blood level of glucose is 200 mg/dl Tm for glucose is reached renal threshold for glucose is exceeded
Failure to empty the bladder before beginning the collection of a timed urine specimen will:
cause falsely increased results
documentation of appropriate handling of specimens for drug analysis is provided by the
chain of custody form
the provide an accurate measure of renal blood flow, a test substance should be completely;
cleared on each contact with functional renal tissue
Source, method of transmission and host are all deemed:
components of the chain of infection
where should labels on urine specimen containers be placed
container
reasons a urine specimen may be rejected
contains toilet paper label and req form dont match outside of container is contaminated with feces
bacterial growth in an unpreserved specimen will
decrease clarity
prolonged exposure of a preserved urine specimen to light will cause
decreased bilirubin
what is the physical property measured by a vapor-pressure osmometer
dew point temp
A class ABC fire extinguisher contains?
dry chemicals
Performing a clearance test using radionucleotides
eliminates the need to collect urine, provides visualization of the filtration
substances that may interfere with freezing point measurement of urine and serum osmolarity include
ethanol lactic acid lipids
a technical error that could cause a discrepancy between freezing point and vapor pressure osmometry readings is;
failure to separate cells and serum
T or F both low and high cell counts can be done by using automated body fluid analysis
false
recommended urine containers should have;
flat bottom capacity of 50 mL disposable
a method of performing automated urine sediment analysis is
fluorescence light
an unpreserved urine specimen left at room temp overnight will have decreased
glucose and ketones
Following fluid deprivation, a patient has a serum osmolarity of 276 mOsm and a urine osmolarity of 1000 mOsm. This patient:
has normal concentration ability
The GHS (Globally Harmonized System) requires the following on a chemical label:
hazard pictogram, signal words, hazard statement
Kidneys with impaired production of ammonia will consistently produce urine with a:
high pH
A procedure with a coefficient of variation of 10% is considered:
imprecise
largest source of error in creatinine clearance tests
improperly timed urine specimens
the enzyme renin is produced by the kidney
in response to low plasma sodium levels
renal tubular acidosis can be caused by the
inability to produce an acid urine due to impaired production of ammonia
the results of a serum osmolality performed by both freezing point and vapor pressure osmometry do not agree. a possible cause of the discrepancy would be;
increased ethanol
increased production of aldosterone causes
increased plasma sodium levels
Urine from a patient with diabetes insipidus has:
increased volume and decreased specific gravity
chain of infection model
infectious agent - bacteria, fungi, viruses, etc. reservoir - humans, animals, insects, fomites, body fluids portal of exit - nose, mouth, mucous mem. Specimen means of transmission - droplet, airborne, contact, vector, vehicle portal of entry - nose, mouth, skin, unsterile equipment, mucous susceptible host - patients, elderly, newborn, immunocompromised, workers
which of the following would not be given to a patient before the collection of a midstream clean catch specimen?
iodine cleanser
The specimen of choice for routine UA is 1st morning because
it is more concentrated to better detect abnormalities
The type of nephron responsible for renal concentration is the
juxtaglomerular
the secretion of renin is stimulated by
macula densa cells
what does a fully automated analyzer provide that a semiautomated analyzer does not?
minimal specimen handling
For active transport to occur, a chemical:
must combine with a carrier protein to create electrochemical energy
Clearance tests used to determine the glomerular filtration rate must measure substances that are:
neither reabsorbed nor secreted by the tubules
Measurement of urine osmolarity is a more accurate measure of renal concentrating ability than specific gravity because:
osmolarity is influenced equally by small and large molecules
urine specimen collection for drug testing requires the collector to do all of the following except
perform reagent strip testing
Persons taking diuretics can be expected to produce:
polyuria
decreased production of ADH
produces a high urine volume
decreased production of aldosterone
produces a high urine volume
what would be least affected in a specimen that has remined unpreserved at room temp for more than 2 hours?
protein
What is urea a product of?
protein and amino acid metabolism
the glomerular filtrate is described as a
protein-free ultrafiltrate of plasma
As the supervisor of the urinalysis lab, you have just adopted a new procedure. You should
put a complete, referenced procedure in the manual
Quality management refers to;
quality of specimens and patient care
For general screening the most frequently collected specimen is a
random one
the function of the peritubular capillaries is
reabsorption and secretion
In automated UA the specific gravity is measured by
refractometry
a cloudy specimen received in the lab may have been preserved using
refrigeration
in the lab the preferred method of urine preservation is
refrigeration
Normal functions of the kidney include
regulating body hydration elimination of nitrogenous wastes regulating electrolyte balance
the p-aminohippuric acid (PAH) test is used to measure
renal blood flow
An employee who is accidentally exposed to a possible blood borne pathogen should immediately:
report to supervisor
Before analysis, a refrigerated urine specimen must be:
returned to room temp
A possible physical hazard in the hospital is;
running to answer the telephone
the primary chemical affected by the renin-angiotensin-aldosterone system is
sodium
the hormone aldosterone is responsible for
sodium retention
the osmotic gradient of the medulla
stimulates sodium reabsorption in the proximal convoluted tubule
The least contaminated specimen for bacterial culture is the:
suprapubic aspiration
If a routine urinalysis and a culture are requested on a catheterized specimen, then:
the culture is performed first
Filtration of protein is prevented in the glomerulus by
the glomerular filtration barrier
ADH regulates the final urine concentration by controlling
tubular permeability
the renal function that is most frequently the first affected by early renal disease is;
tubular reabsorption
endogenous clearance test substances
urea creatinine Beta2 microglobulin NOT INULIN
and unidentified fluid is received in the lab with a request to determine if the fluid is urine or another body fluid. which substances would determine that the fluid is most probably urine
urea and creatinine
following administration of oral ammonium chloride, a patient with renal tubular acidosis will produce
urine with a high pH
the renin-angiotensin-aldosterone system is responsible for;
vasoconstriction of the efferent arteriole reabsorbing sodium releasing aldosterone
a solute dissolved in a solvent
will lower the freezing point
Lab accrediting organizations
§The Joint Commission (TJC) §College of American Pathologists (CAP) §American Association of Blood Banks (AABB) §American Osteopathic Association (AOA) §American Society of Histocompatibility and Immunogenetics (ASHI) §Commission on Laboratory Assessment (COLA)
