renal testing Flashcards
what enzymes/hormones do nephrons secrete (3)
- hemodynamics regualtors (renine)
- EPO
- Vitamin D
Measures amt nitrogen in blood in the form of urea
BUN
urea is ___by liver and ___by kidneys
excreted by liver and removed from blood by kidneys
incr in BUN is?
azotemia
the sum of filtration rates in all functioning nephrons
GFR
normal amt filtered by glomeruli
150-180 liters
Cr is lowest____and highest____
in AM; at night
BUN:Cr ratio > 20:1 indicates that problem is where
pre renal
BUN:Cr ratio 10-20:1
normal or post renal
Bun:Cr ratio
renal
as your Cr incr, what happens to your GFR?
decr
UTI or citrus fruit can lead to what change in pH in urine
incr
dehydration, cranberries can lead to what change in pH in urine
decr
normal urine pH
4.5-8
when the kidney can’t reabsorb filtered glu in PCT despite normal plasma levels
renal glucosuria
low sp gravity can indicate
- overhydration
2. renal disease
high sp gravity can indicate
dehydration
UA component associated with high false positive rate
leukocytes
UA component associated with high false negative rate
nitrites
what can lead to false positives on UA blood (4)
- alkaline urine
- contamination with oxidizing agents
- semen
- myoglobin
if blood is 1-4+ what is f/u?
microscopy
alb detection that is greater than normal but wouldn’t be detectable on dipstick
urine microalbumin
urine microalbumin is seen with?
DM, HTN
typical MA/Creatinine ratio
0-30 mg/g
if glomerular issue is cause of proteinuris, expect Up:Ucr ratio ____
> 3
definition of pyuria
> 4 WBC/HPF
if epithelial cells are detected in casts, then?
tubular origin
RBC casts
glomerulonephritis
WBC casts
pyelonephritis, acute tubular necrosis
fatty casts
nephrotic syndrome
waxy, broad casts
advanced renal failure
calcium oxalate crystals + acute renal failure
think ethylene glycol poisoning
struvite crystals
proteus infxns
fractional excretion of Na under 1%
prerenal disease
fractional excretion of Na >2%
acute tubular necrosis
what is the most common intrinsic cause of acute renal failure in hospitalized patients?
acute tubular necrosis
high uric acid with recent chemo
tumor lysis syndrome