Flashcards in GFR & Proteinuria Labs - Cohen Deck (14):
What are symptoms of kidney failure? What causes them?
Frequency or Nocturia- large urine output
Edema- protein loss
Foamy Urine- protein loss
Uremia- waste product retention
What are the formulas for filtration and excretion?
What is the formula for calculating GFR based off of this?
Q_filt= GFR * [serum]
Q_excr= UFR * [urine]
GFR= (UFR*[urine]) / [serum]
What is used to measure the GFR? Why?
Creatine; it assumed to be neither excreted or resorbed
Another option is inulin, but that is not produced endogenously.
What is the normal range for serum creatinine?
0.9-1.3 mg/dL for men
0.8-1.0 mg/dL for women
0.5-1.0 mg/dL for kids
These are all HIGHLY variable.
What are the stages of kidney failure?
Stage I- 100-90 ml/min
Stage II- 89-60 ml/min
Stage III- 59-30 ml/min
Stage IV- 29-15 ml/min
Stage V- less than 15 ml/min
What three factors can affect serum creatinine calculations?
Age (older people produce less creatinine)
Gender (females produce less creatinine)
Race (blacks produce more creatinine)
What is the Cockcroft-Gault equation?
this is multiplied by 0.85 in women
What are some limitations with calculating creatinine clearance?
Depending on the formula used, there can be a lot of variability.
Is not useful for acute kidney injury
How is proteinuria measured? What is the accuracy?
Collected urine has a dipstick, which changes color according to protein content.
How can urine be collected for proteinuria testing?
24 hour collection
spot collection (less accurate)
How is proteinuria quantified?
Do healthy people have protein in their urine?
Yes, tubular proteins
What is micro-albuminuria?
A moderate increase in albumin in the urine
30-300 mg albumin in 24 hours
20-200 ug albumin per minute