Urinalysis Flashcards
Joanne has chronic kidney disease with a GFR of about 20 ml/min. What is the specific gravity of her urine?
a. 1.010
b. 1.035
c. 1.005
d. 1.020
a. 1.010
in the urine dipstick, ___ is isoosmolar
less is ___ and more is ___
1.010
hypotonic
hypertonic
what happens in renal tubular acidosis with a LOW pH?
- loss of proximal tubule HCO3 reabsorption
- collecting duct can still acidify/secrete
what happens in renal tubular acidosis with a HIGH pH?
-the collecting duct is unable to secrete acid/generate an H-gradient
the filtration barrier of the kidney usually filters out things that are bigger than ___ kDa
40
where are proteins reabsorbed?
the proximal tubule
how much glucose can the kidney reabsorb?
about 180
how does the dipstick measure cells?
only by measuring cell products like leuk esterase and hemoglobin
how many RBCs are in a normal urine sample?
0-3
how many WBCs are in a normal urine sample?
0-5
if you see…
- a dipstick hemoglobin positive but no RBCs
- or many bacteria but no WBCs
- or many amorphous crystals
- -what is going on?
old urine specimen
what does it mean if there are dysmorphic RBCs in the urine?
there is a glomerular problem (they are getting injured as they squeeze through)
hyaline casts
non-pathogenic, clear
granular casts
non-specific, if there are a lot it can mean there is acute tubular necrosis/acute kidney injury
WBC casts
- pyelonephritis
- interstitial nephritis
epithelial cell cast
-seen in acute kidney injury
active sediment
RBCs and WBCs in the urine, signifies acute glomerular nephritis
what does bacteriuria with a big squamous cell suggest?
contamination (not concerned about UTI unless there are symptoms)
what do triple phosphate (struvite) crystals look like?
coffin lid
what do urate crystals look like?
- birefringent
- rhomboid or rosettes
what do cystinuria crystals look like?
hexagonal
what do indinavir crystals look like?
brushy
what do calcium crystals look like?
envelope, dumbell shape
what measurement is used to stage diabetic nephropathy and predict CV risk?
albumin
what do we measure to predict stone risk?
calcium salts, urate, citrate
what does a low fractional excretion of Na mean?
-you are reabsorbing sodium because you are dehydrated
what is urine sodium if you have a pre-renal problem? what about acute kidney injury?
<20, >40 mEq/L
FE Na in pre-renal problem? what about acute kidney injury?
<1%, > or = 1%
FE Urea in pre-renal problem? what about acute kidney injury?
<35%, >50%
UrineCr/PlasmaCr in pre-renal problem? what about acute kidney injury?
> 40, <20
what is the normal protein/Cr ratio?
< 150 mg/g
what is a normal albumin/Cr clearance?
<30 mg/day
what is microalbuminuria?
albumin/Cr clearance of 30-299
what is macroalbuminuria?
albumin/Cr clearance of >300
what is the recommended daily intake of sodium? how much comes out in the urine?
2300 mg, pretty much all of it
what is a normal protein /day?
<300 mga
what is a normal creatine clearance?
90-130 ml/min
NGAL (neutrophil gelatinase associated lipocalin)
a marker that can demonstrate acute kidney injury earlier than creatinine
-not certain clinical application
