biochemical markers Flashcards
ideal marker of GFR
- appear at a constant rate
- be freely filtered by the glomerulus
- not be reabsorbed by the renal tubule
- not be secreted by renal tubule
- not undergo extra-renal elimination
what does measuring inulin do
give you a good assessment of GFR
what is urea
end product of protein metabolism
does urea appear at a constant rate
no
what will using urea to measure GFR do
underestimate GFR
what is creatinine
product of muscle metabolism
-people with more muscle will release more
how good is creatinine at measuring GFR
in renal failure is creatinine high or low
very high
what is the problem with using creatinine as a GFR marker
creatinine isnt sensitive to changes in GFR until GFR is quite low
what is urinary creatinine clearance
the volume of blood thats cleared of creatinine per minute by glomerular filtration
calculation for urinary creatinine clearance
how many stages of CKD are there
5
what is eGFR for CKD 5
0-20
why is eGFR not perfect way to measure
not very accurate at higher GFR
what is the validated reference standard for accurate assessment of GFR
Cr-EDTA
if protein is >150mg/day what does this mean
significant glomerular damage
how do you measure proteinuria
24-hour collection
do you see proteinuria in multiple myeloma
yes
proteinuria in nephrotic syndrome?
yes
what happens in nephrotic syndrome
less albumin in blood so water goes out and causes oedema
what does a positive bence jones proteinuria suggest
multiple myeloma
what is microalbuminuria
excretion of albumin in abnormal quantities but still below the limit of protein detection by dipstick
what is microalbumminuria and early detection of
diabetic nephropathy
ways of expressing proteinuria
what does osmolality tell you
how concentrated or dilute a biological fluid is
