Exam 3: AKI Flashcards
The term Acute renal failure (ARF) is now reserve for severe ** and implies the need for **.
AKI
Dialysis
What is it called when you have abrupt loss of kidney function resulting in retention of urea and other nitrogenous waste products, as well has dysregulation of volume status and electrolytes?
AKI
What is the diagnosis of AKI based on?
Based on serum creatinine levels or a decrease in patients urine output
What are the potential problems of diagnosing AKI using creatinine?
- in early AKI, serum creatinine may be low even low GFR is markedly reduced
- Creatinine is removed by dialysis so it is not possible to assess kidney function using creatinine when on dialysis
- There is no consensus on what creatinine level actually indicated AKI
What is the diagnostic levels used to confirm AKI?
- Increase in serum creatinine by >0.3 within 48 hours
- Increase in serum creatinine to >1.5 times baseline
- Urine volume < 0.5ml/kg/hr for six hours
If patient has creatinine around 1.9 x their baseline, what stage of AKI are they?
Stage 1
If patient has anuria for <12hrs, what kind of AKI stage are they?
Stage 3, needs dialysis
AKI develops in up to *** of ICU patients?
60%
What are the 3 etiologies of AKI?
- prerenal (decreased renal perfusion)
- Intrinsic renal ( pathology of vessels, glomeruli, or tubules)
- postrenal (obstructive)
AKI in the hospital is most often from ** disease or **.
Prerenal or acute tubular necrosis (ATN)
What is the most commo cause of AKI?
ATN with prerenal being next
What is the least common cause of AKI?
Obstructive (10%)
What are the 5 causes of prerenal disease?
- True volume depletion (GI loss, burns, respiratory loss)
- Hypotension (shock)
- Edematous states (HF, cirrhosis)
- Selective renal ischemia (bilateral renal artery stenosis)
- Drugs affecting GDR (NSAIDS and ACE inhibitors)
What are the causes of intrinsic renal disease?
- Renal ischemia
- Sepsis
- Nephrotoxins (IV CONTRAST)
How does IV contrast cause Intrinsic renal disease?
It causes renal tubular epithelial cell toxicity and renal medullary ischemia from vasoconstriction
What are the risk factors for Contrast induced ATN?
- Preexisting renal disease
- volume depletion
- repeated doses of contrast
- DM, CHF, and age
What is the prevention of contrast induced ATN?
- Hydration
- Low osmolal agents at low dose
- avoid repetitive doses
- Avoid nephrotoxic drugs
What is the cause of post renal disease and what are common examples?
- Obstruction of the flow of urine
- prostatic disease (cancer or hyperplasia), metastatic cancer, and neurologic disease (neurogenic bladder and urinary retention)
If patient has a reduction in GFR and no intrinsic renal disease, what does this mean?
There needs to be BILATERAL obstruction. One kidney stone wont decrease GFR because the other kidney will take over
What is considered nonoliguric?
> 400ml/24hrs usually 1-2 L/day
What is considered oliguric?
<400mL/24hrs
What is considered anuric?
<50 to 100ml/24 hours
What labs do you want to order in a patient with AKI?
- Urinalysis
- Serum metabolic panel (creatinine, GFR, and fractional excretion of Na+ (FENa)
What imaging is commonly helpful in AKI?
Renal US
What are the 3 components of urinalysis?
- Gross eval
- Dipstick analysis
- Microscopric examination