AKI Flashcards
What must be present to confirm an AKI?
- SCr increase >/= 0.3 mg/dL within 48 h
- SCr increase by at least 1.5 times baseline in 7 days
- decrease in volume to less than 0.5 ml/kg/h
What is a stage 1 AKI?
- SCr increase >/=0.3 OR
- 1.5-1.9 fold increase in SCr from baseline OR
- <0.5 ml/kg/h for >/= 6-12 h
What is a stage 2 AKI?
- SCr increase 2-2.9 fold from baseline OR
- <0.5ml/kg/h for >/=12h
What is a stage 3 AKI?
- SCr > 3 fold increase from baseline OR
- SCr >/= 4mg/dl OR
- need for RRT OR
- eGFR <35 in patients < 18 years old OR
- anuria >/= 12h
Who made the stages for AKI?
KDIGO
How long does it take for SCr to increase after the start of an AKI?
1-2 days
What are the causes of a prerenal AKI?
- hypovolemia
- reduced cardiac output
- systemic vasodilation
- renal vasomodulation/ shunting
What are the causes of an intrinsic AKI?
- vascular/microvascular
- glomerular injury
- tubulointerstitium (obstruction)
What are the causes of postrenal AKI?
- bladder outlet obstruction
- ureteral obstruction
- kidney stones
- swelling of abdomen
- cancers
What is a diagnostic tool for differentiating AKI?
Fraction Excreted Na (FENA)
What type of AKI has characteristics of low urine sodium and a FENA of <1% ?
prerenal
What type of AKI has characteristics of elevated urine sodium and a FENA of 2-3% ?
intrinsic
What are clinical presentations of an AKI?
- decreased urine output
- urine discoloration
- sudden weight gain
- severe abdominal or flank pain
What labs indicate an AKI?
- elevated BUN
- increased SCr
- BUN:Cr ratio
- FENA
What can alter the accuracy of FENA equation? What should be done?
- diuretic use
- see how long the drug lasts
What is the mechanism of prerenal AKI?
decreased renal perfusion usually due to volume depletion
What is the mechanism of intrinsic AKI?
structural damage to the kidney tissue usually due to ischemia or toxins
What is the mechanism of post renal AKI?
obstruction of urine flow downstream
What is the most common type of hospital/ ICU aquired AKI?
intrinsic
What FENA, BUN/SCr, specific gravity indicates prerenal AKI?
- FENA: <1
- BUN/SCr : >20 (dehydration)
- urine specific gravity: >1.018
What FENA, BUN/SCr, specific gravity indicates intrinsic AKI?
- FENA: >2
- BUN/SCr : ~15
- urine specific gravity: <1.012
What FENA, BUN/SCr, specific gravity indicates postrenal AKI?
- FENA: variable
- BUN/SCr : ~15
- urine specific gravity: variable
How do we prevent AKIs?
- review medications for nephrotoxicity
- adjust renally cleared meds
- optimize hemodynamics
- hydration
What prevention strategy consistently shows benefit?
hydration
When should hydration be given to patients receiving contrast dyes?
prior to and after receiving contrast dyes
What fluids are options to prevent AKI?
- NS
- sodium bicarbonate
- plasmalyte
- lactated ringers
What is the glycemic target for ICU patient?
140-180 mg/dL
What are nonpharm therapies for AKI?
- fluid boluses with NS
- red blood cell transfusions
- elimination of meds associated with kidney damage
- electrolyte management
- improve cardiac output
- RRT
What are treatments to manage fluid overload?
- IV loop diuretics
What is the mechanism of diuretic resistance?
1.decreased diuretic secretion into the tubular lumen
2. severe hypoalbuminemia
What are treatment options for diuretic resistance?
- high dose IV bolus doses
- continuous infusion of diuretics
- 25% albumin and loop
- loop and thiazide
What are the indications for RRT?
A: acid/base abnormality
E: electrolyte imbalance (hyperkalemia, hypermagnesemia)
I: intoxications
O: fluid overload
U: uremia
What drugs can lead to RRT?
- salicylates
- lithium
- methanol
- ethelyne glycol
- theophylline
- phenobarbitol
The use of what fluids are associated with having proinflammatory effects and can activate leukocytes if used for fluid management of AKI?
LR
