Renal function tests and proteinuria Flashcards
what is the normal threshold of protein in urine
what are some benign proteinuria conditions
normal level: 150mg/DAY
benign condition:
- orthostatic proteinuria: prolonged standing
- transient proteinuria: fever (systemic diseases), infection, exercise
what are the 2 criteria for UTI
- pyuria = leukocyte presence and bacteria presence
2. significant bacteuria: 10^5 cfu
what is renal clearance and under what circumstances can it be used as estimation of GFR
renal clearance: volume of blood that is cleared of a substance per minute
- freely filtered
- not reabsorbed
- not secreted by tubular cells
- not metabolised or synthesised by tubular cells
- kidney must be the sole route of excretion
what is the current standard when wanting to learn about renal function (ie GFR)
- plasma creatinine (instead of eGFR)
- plasma urea
- plasma Cr derived formula: CKD-EPI
why is eGFR not used, and what is the gold standard for GFR analysis
- eGFR not used: error prone, inconvienient (urine 24 hour collection)
- infusion study is the gold standard (inulin)
what are some limitation with regards to creatinine
- largely dependent on muscle mass
= age, ethnicity, diet, body status, drug intake influences it
what is cystatin c
new potential marker for GFR estimation
- reabsorbed at proximal tubule and catabolised
- if present in urine = proximal tubular damage
when should urine protein concentration bemeasured
anything related to renal disease
diabetes
new haematuria, unexplained odema
stip test agent
tetrabromphenol blue + citrate pH buffer
- protein = green colour change
sulfosalicylic acid = turbidity
microalbuminuria
non-detectable by less sensitive tests
- detectable by laboratory tests
- its presence is significant as it signals early intervention before rapid decline in GFR in diabetic patients
myoglobin is toxic to renal tunular cells
tubular injury
