Diagnostic Laboratory Medicine Exam 1 Flashcards
Urine Testing, Stool Testing, and Other Common Medical Tests
What is a Urine Culture (C&S)? What is it used for?
Culture & Sensitivity, used to see what bacteria are growing
What test would you order to see if E. coli is in the urine?
Urine culture
What is a Routine UA?
Urinalysis that is a rapid tests to test for many different things = Macroscopic
How long does it take for a urine culture to come back? UA?
Culture = 24-48 hrs, UA = rapid, 2 mins
Why would you order a Microscopic UA?
gives rapid cell count
Urine Pregnancy tests are (quantitative/qualitative)
QUALitative (yes/no)
T/F - Random collections must be taken in the morning
False, they can be taken anytime of day
Random collections are (sterile/nonsterile)
Non-sterile
T/F - Pregnancy tests are most accurate during the (night/morning)
Morning
What test reflects the ability of the kidney to concentrate urine during dehydration?
Early morning collection
What is a timed urine test? Why would it be used? Should it be refrigerated?
24 hour urine collection that looks at renal and endocrine problems. Yes, refrigerate!!
T/F - A patient can touch the inside of the lid for a clean-catch midstream urine specimen
False, this provides contamination
What is the most sterile way to obtain urine through the urethra? Through a needle?
Catheterization, Suprapubic transabdominal needle aspiration
What is the most common microorganism in a UTI?
E. coli
If a urine specimen is left out, what should you do with it?
Refrigerate
What is the MIC?
Minimum Inhibitory Concentration (Least amount needed to kill bacteria)
A positive urine culture is at or above what number?
1 x 10^5 CFU/mL (100,000)
What are some positives of a Macroscopic UA? What is another name for it?
URINALYSIS, Inexpensive, readily available, useful indicator of body’s major metabolic functions, uses disposable strips
How long does the test for a Macroscopic UA take? Is it time sensitive?
2 minutes, yes!!
What is the first part of UA? What is normal?
Direct visual observation, normal, fresh urine is pale to dark yellow and clear (not cloudy or turbid)
What causes cloudiness or turbidity?
Excessive cellular material or protein in the urine, may develop if it sat too long
Give the reasons for a red or red-born color of urine
Beets, food dye, a drug or multivitamin, presence of hemoglobin or myoglobin, or possibly from menstrual drips
(If many RBC, will be red and cloudy)
What are some benefits to using an automated UA?
Accurate, easier
T/F - There’s a variety of dipstick types that test for different things
True
Name 10 things that the Urine Dipstick tests for
pH, ketones, glucose, protein, specific gravity, nitrites, bilirubin, urobilinogen, blood, and leukocytes
When something is bold on a UA result, what does that mean?
It is abnormal
Give the range for a urinary pH
4.5-8.0
Give reasons for a high urine pH or low urine pH. What is it important in managing?
High: -UTI
-Kidneys not properly removing acids from bloodstream
Low: -Diarrhea -Starvation
Important in management of bacteriuria, renal calculi, drug treatment
What does specific gravity measure?
urine density, or the ability of the kidney to concentrate or dilute the urine over that of plasma
Give a normal specific gravity range
1.002-1.035
Name some reasons for a high SG or a low SG
High: Dehydration, Diabetes Mellitus, CHF, nephrosis
Low: Severe renal damage, diabetes insipidus, over hydration
T/F - Healthy urine contains some protein
False, should contain none or trace amounts
Proteinuria is seen with what illnesses?
Glomerular damage or diminished tubular reabsorption
What does a large number of leukocytes + proteinuria indicate?
Infection at some level of urinary tract: UTI, pyelonephritis (bacterial infection), nephrolithiasis (kidney stones)
Glucose is primarily present in urine with which condition? What else could be the reason?
Diabetes mellitus, can also be present with endocrine, liver, or pancreas disease
If you see POSITIVE ketones + POSITIVE glucose in urine, what should you suspect?
Diabetic ketoacidosis, BGL is VERY high if glucose is spilling into urine
T/F - Ketones should be found in some amounts in the urine
False, they are completely metabolized, so normally only negligible amounts should be found in urine
What organ makes ketones?
Liver
Ketonuria (high levels of ketones) indicates that a person is in a (anabolic/catabolic) state and is breaking down (carbs/fat/protein)
Catabolic, fat
What suspicions should you have for someone with ketonuria?
UNDIAGNOSED EATING DISORDER (altered carb. metabolism from starvation), acute illness, diabetes mellitus that is at risk for diabetic ketoacidosis
What does a POSITIVE nitrite test indicate?
Bacteria may be present in significant numbers in the urine
Positive Nitrite + Leukocytes should cause a suspicion of ?
UTI
What are leukocytes?
White Blood Cells as a whole or as lysed cells
What is the next step if someone tests positive for nitrites and leukocytes?
Order a culture for bacterial identification
What would cause a false positive on a UA?
Leaving urine out at room temp. too long, causing bacteria to multiply
What is pyuria?
When urine sample contains elevated WBCs and pus
What is hematuria?
Blood in the urine
T/F - Hematuria can only be macroscopic
False, can be MACRO and MICRO scopic
The UA dipstick can detect hematuria with a sensitivity of 90% with more than _____ RBCs/HPF
3
What causes hematuria?
Damage to the bladder, kidneys, or urinary tract. Can also be from menstruation. UTI, Kidney stones, Exercise, Trauma, Endometriosis.
IN ELDERLY PTS, BLADDER, KIDNEY, OR PROSTATE CANCER
Bilirubin and urobilinogen will appear in the urine before other signs of which organ dysfunction?
Liver
What does a elevated bilirubin and urobilinogen levels possibly indicate?
Early sign of possible hemolytic disorders (pernicious anemia)
What is the term for abnormally shaped cells from kidney issues?
Casts
Give examples of what a MICROscopic UA might contain
RBCs
WBCs
Bacteria
Yeast
Casts
Crystals
Sperm
Misc
Name the 2 types of Serum pregnancy tests and their levels
Qualitative (5-10 IU/L), Quantitative (1-2 IU/L) to test how much hCG
What hormone is a pregnancy test testing for?
hCG
T/F - After abortion or miscarriage, hCG can still be positive for a period of time
True
How soon can pregnancy be detected on a test?
6-12 days after conception
Reason for false negative and false positive pregnancy tests?
False Neg: performed too soon
False Pos: Preg. lost after implantation
Tool for catching clean stool specimen
Hat
Name the items in a Macroscopic Stool Sample
Color
Amount
Consistency
Odor
Gross blood (Seen)
Mucus, Pus
Name the items in a Microscopic Stool Sample
Occult Blood (Hidden)
Ova/Parasites
Bacteria
Viruses
Yeast
Leukocytes
Fecal Occult Blood Test tests for what?
Blood in stool
What is the replacement for FOBT tests?
FIT (Fecal Immunochemical Test)
-Unaffected by diet or meds, unlike FOBT
-First line rec. Uses a monoclonal or polyclonal antibody
-Superior Sensitivity
Name for the cancer prescreening test at home
Cologuard
T/F - C. diff is spore-forming and is infectious
True
What would you use to assess a wound?
Wound Cultures, testing for MRSA, Staph, etc.
Bacteria are responsible for how much of all pharyngitis cases?
5-10%
What do throat cultures interpret?
Group A hemolytic Streptococci, Neisseria gonorrhoeae, and bordetella pertussis (whooping cough)
What is the most common bacterial etiology of pharyngitis?
Streptococci, or strep throat
The likelihood of a positive Influenza test happens when it is obtained how long from symptom onset?
24-72 hours
When are Influenza results available after rapid antigen test?
10-30 minutes
Mononucleosis, or ___ ___ Virus, is detected how?
Epstein Barr Virus, fingerstick blood test
When is mono testing most accurate?
More than 80 percent sensitive in the SECOND WEEK, 1/3 of cases are missed in the first week
T/F - CBC will show atypical lymphocytes with mono
True, indicative of disease
Name some other onsite rapid tests
HIV, Hepatitis B or C, INR, Hemoglobin A1C
Diabetic with proteinuria (with no other infection or related causes) means there is high risk of ?
Chronic kidney disease
A pt presenting with edema and proteinuria is a symptom of what ? The pt also was later diagnosed with Hepatitis C
Nephrotic syndrome (damage to blood vessels in kidneys that filter waste)
What is the cause associated with over 50% of bladder cancer?
Smoking
Pt presents with lupus (an autoimmune disease that tends to develop kidney issues), fatigue, and peripheral edema. What would be positive in their urine?
Protein, blood - lupus is major clue of kidney issue
T/F - A negative nitrite UA means there is no bacteria in the urine
False. There is still bacteria, but not significant amounts
T/F - A negative leukocyte esterase test means that infx is unlikely and without additional symptoms, urine culture does NOT need to be done to rule out significant bacteriuria
True
T/F - A positive Cologuard result is diagnostic for cancer
False. Could indicate cancer, but need further testing
What is the sensitivity to the rapid strep tests?
70-90%
What organism most commonly causes strep throat
Group A hemolytic streptococci
What organism is responsible for STI gonorrhea? G - or G + ? Shape?
Neisseria Gonorrhoeae
Gram negative coffee bean shaped diplococci
What organism is responsible for whooping cough? G- or G+? Aerobic or anaerobic? Shape?
Bordetella pertussis
Gram -, aerobic, pathogenic, encapsulated coccobacillus
