Tests of renal function and hyrdation status Flashcards
1
Q
Renal function
A
- Excretion - urea
- Regulation - Homeostasis, water, acid base
- Endocrine - renin, erythropoietin
2
Q
Use of Renal function tests
A
- Detect renal damage
- Monitor functional damage
- distinguish between impairment and failure
3
Q
Pre-renal kidney failure
A
- poor perfusion of nephrons, which in turn leads to a decrease in the GFR
- Decreased ECFV or MI
4
Q
Renal kidney failure
A
- unable to filter waste products from your blood
- Waste accumulates
- Acute tubular necrosis
5
Q
post-renal kidney failure
A
- obstruction in the urinary tract below the kidneys causes waste to build up in the kidneys
- Ureteral obstruction
6
Q
Anuria
A
- Failure of the kidneys to produce urine
7
Q
Oliguria
A
- Oliguria is defined as a urine output that is less than 400 mL/24 h or less than 17 mL/h in adults
8
Q
Polyuria
A
- Polyuria is a condition characterized that there is large volumes of urine (at least 3000 mL over 24 h)
9
Q
Normal urine volume
A
- Normal volume is 750-2000 mL/24h
10
Q
Plasma urea
A
- Wide reference range 3-8mmol/L
- Increased in GI bleed, trauma
11
Q
Urea excretion
A
- Urea filtered by glomerulus - 40% reabsorbed by renal tubules
12
Q
Renal hypoperfusion
A
- More urea reabsorbed if rate of tubular flow is slow Causes: - RA stenosis - decreased RBF due to MI - Fluid loss
13
Q
Plasma creatinine
A
- Normal = 50-140
- Increases in conc as GFR decreases
- Not proportional to renal damage
- High muscle mass means more creatine
14
Q
GFR measurement
A
- Measured for donors and chemotherapy patients to calculate drug dosage required
- radioactive substances used
15
Q
eGFR
A
- 90+ = normal
- 60-90 = mildly reduced kidney function – control BP and risk factors
- 30-59 = moderately reduced kidney function – control BP and risk factors
- 15-29 = severely reduced kidney function – planning for end stage renal failure
- <15 or on dialysis = very severe, endstage/established renal failure – transplant/ dialysis
