1-2 Flashcards
The kidney serves to eliminate what waste products?
Urea
Cr
Uric acid
Kidney failure is characterized by a GFR of ____. It is stage ___ of CKD.
<15
5
CKD is defined as either of the following:
- Kidney damage for at least 3 months (with or without decreased GFR)
- GFR <60 mL/min/1.73m^2 for at least 3 months (with or without kidney damage)
- What is uremia?
- When will you see symptoms?
- What are the symptoms?
- Retention of nitrogenous waste products
- When GFR<15 mg/min
- Confusion, encephalopathy, dizziness, nausea, vomiting
Exogenous filtration markers:
Inulin
Iothalamate
EDTA
Iohexal
Endogenous filtration markers:
Creatinine
Cystatin C
- Creatinine overestimates GFR by about ____.
2. What inhibits creatinine secretion? (Without affecting GFR)
- 10-40%
2. Trimethoprim and cimetidine
Generation of creatinine is higher in:
Men Young Black Muscular Those who eat cooked meat
Extra-renal excretion of Cr is ___ in pts with CKD
Higher
Factors that increase serum Cr:
Kidney disease Cooked meat Trimethoprim cimetidine Flucytosine Some cephalosporins Ketoacidosis
Factors that decrease serum Cr:
Reduced muscle mass
Malnutrition
The Crockcroft-Gault equation is used to estimate ___. What is it?
Cr Clearance
CCr= ((140-age)•lean body weight)/ Cr•72
Creatinine production ____ with age and ____ with increasing body mass.
Decreased
Increases
What does the MDRD account for that the Crockcroft-Gault equation does not?
Body surface area
In the MDRD equation, GFR is measured by ___
Urinary Clearance of 125I-Iothalamate
Both the MDRD and the Crockcroft-Gault equations are less accurate in ____ but fairly accurate ___. Both overestimate in ____ populations.
- Obese patients
- Across age ranges (CG overestimates a little in both younger and older)
- Asian
How is BUN related to GFR? Is it more or less accurate than Cr? Why?
Inversely
Less
Urea production is less constant.
About ___% of filtered urea is passively reabsorbed in the proximal tubule
50
Urea production is increased with ___
And decreased with ___
I: high protein diet, corticosteroids, hemorrhage, trauma, and tissue breakdown
D: liver disease and low protein diet
Cystatin C has a low molecular weight (13 KD) and is freely filter by the kidneys. It is then reabsorbed and catabolized by ____. Very little is excreted in the urine, so it cannot be measured for urinary clearance.
Tubular epithelial cells
___ is the most common protein found in proteinuria. Normal excretion is about ____
Albumin
10mg/day
Normal total protein excretion is __.
____ samples are best
Less than 50 mg/day
First morning
___ is recommended for pts with, or at risk for CKD.
Urine sediment
Stage 1 CKD
Kidney damage
Normal or increased GFR >90
Treat coexisting conditions
Slow progression
