Urinalysis Flashcards
Serum creatinine and BUN rise after glomerular filtration rate falls below __________.
40 ml/min
Why is creatinine a good indicator of GFR?
Because it is not reabsorbed (mostly)
It is not bound to plasma proteins
It is only partially secreted by the peritubular capillaries
Urine must be analyzed within _____ hours to be accurate.
two (if you need to wait longer than two hours, then the sample must be refrigerated)
Polyuria is roughly defined as ____________.
greater than 2 liters of urine in 24 hours
For urine cultures, incubation must be done for longer if the patient ___________.
is receiving antibiotics
What are 24-hour samples used for?
Hormone detection, protein electrophoresis, and electrolyte analysis
Anuria is defined as less than __________.
100 ml of urine over 24 hours
List the colors of some common urine abnormalities.
Bile: yellow/green/brown
Urobilinogen: orange/red/brown
Blood and hemoglobin: red/pink
Methemoglobin, L-dopa, rhabdomyolysis: black
Reagent strips must be ____________.
kept in a cool, dry space with a tight lid
Reagent strips should be placed into urine for no longer than ________.
one second
Alkaline urine is a hallmark of __________.
renal tubular acidosis
Normally, there is less than _______ grams of protein in a day’s worth of urine.
0.5
What are some patient characteristics that might increase protein content in the urine?
Age (i.e., the elderly)
Posture (standing makes you have more protein in the urine)
Nephrotic syndrome
Multiple myeloma
What two proteins account for most of the urinary protein?
Albumin and Tamm-Horsfall
Proteinuria is defined as __________.
greater than 150 mg/dl
Glucose is normally _________ in urine.
undetectable
Four conditions can lead to glucose in the urine. What are they?
Diabetes, endocrine disorders, pregnancy, and pancreatic disorders
__________ are indicative of Gram-negative bacteria in the urine.
Nitrites
Even refrigerated urine samples cannot be analyzed after ________.
24 hours
Oliguria is defined as __________.
less than 500 ml of urine in 24 hours
Do not spin urine samples for ________ testing.
dipstick
High specific gravity in a patient with oliguria indicates ____________.
a pre-renal disorder
What would the urine pH be in metabolic or respiratory acidosis?
low
What organism can cause markedly high pH in a UTI?
Proteus
We normally excrete less than ______ grams of protein per day.
0.5
On the +1 to +4 scale, what is proteinuria?
At least +3 (+3 is 200 mg/dl, and you need greater than 150 mg/dl to qualify as having proteinuria)
The dipstick glucose tests only detect _________.
glucose–no other forms of sugar will be detected
If microscopy reveals no RBCs, but the sample tests positive for blood, what is the conclusion?
Presence of hemoglobin!
Free RBCs indicate _____________.
post-renal injury
___________ is an indicator of neutrophils in the urine.
Leukocyte esterase
What can you collect in centrifuged samples?
CCCO Cells Casts Crystals Organisms
Having a few hyaline casts is normal, but more indicate ______________.
dehydration, fever, or renal injury
Matrix casts are indicative of ___________.
chronic renal failure
Uric acid crystals are nonspecific, but increased numbers suggest _____________.
increased cell turnover (such as in chemotherapy) or Lesch-Nyhan disease
Dysmorphic RBCs indicate _________ origin.
glomerular
The __________ void is the preferred for analysis.
first morning
What else (other than DKA) can cause ketones in the urine?
Alcoholism
Cirrhosis
Fasting
Prolonged exercise
