Caster- Approach to AKI Flashcards
Does Cr clearance over- or under-estimate GFR? by how much? and why?
it over estimates it by 10-15% because that much is secreted by the PCT
Cr is derived from what?
mtb of creatine in skeletal muscle
What is required for accurate Cr level measurement
steady state
Cr level depends on what 3 things?
Age,
Muscle Mass/weight,
Gender
Cr levels are higher in what race
AA
The most dangerous/extreme changes in kidney function occur when Cr increases from what to what?
1-2
What is normal serum level for Cr?
0.6 - 1.2
define AKI
decline in renal function that occurs over hours-days
serum Cr increase 1–> 2 represents what % decrease in GFR?
50%
serum Cr increase 2 –> 3 represents what % decrease in GFR?
17%
What 4 tyhings are you unable to do in AKI
- excrete waste
- regulate volume
- Manage electrolytes
- make bicarb
What is stage one of AKIN criteria designed to catch and how
it catches early changes in kidney function by being the stage that occurs if sCr increases >0.3mg/dl
both RIFLE and AKIN criteria for AKI measure what two criteria (either of which can be used)
Serum Cr or Urine Output can be used
4 risk factors for AKI
CKD
DM
Heart or Liver dysfunction
Age >50
define azotemia
increased BUN and Cr
3 presenting things with AKI
Azotemia
Oliguria
Electrolyte Imbalance
define Oliguria
< 400 ml/day
define Anuria
< 50 ml/day
3 major causes of AKI
pre-renal
intra-renal
post-renal
What are the four intra-renal locations of AKI
tubular
Interstitial
GLomerular
Vascular
What are 2 indications for doing a renal biopsy on AKI pt?
1) Acute glomerulonephritis suspected (proteinuria, hematuria, RBC casts)
2) If etiology of AKI unclear or recovery is not as expected
Urinalysis shows muddy brown casts = what dx?
ATN
pre-renal AKI is caused by hypoperfusion cuased by what two things?
hypovolemia- (improves with fluids)
Decreased effective BV
What 3 conditions cuase decreased effective BV?
CHF
Cirrhosis
Sepsis