Acute Kidney Injury Flashcards
What is Acute Kidney Injury defined by?
1) Increase in SCr by 0.3 mg/dl ( 26 mol/l) within 48 hours; or
2) Increase in SCr to 1.5 times baseline, which is known or presumed to have occurred within the prior 7 days;
or
3) Urine volume <0.5 ml/kg/h for 6 hours.
What is AKI?
-The sudden, acute drop in function occurring over a period of hours, days or weeks
Is AKI reversible?
Depends on cause, or may lead to permanent renal failure
What is AKI characterized by?
Fluid, electrolyte and acid-base imbalances and wasting
What are some exposures which may lead to AKI?
- Sepsis
- Critical illness
- Circulatory shock
- Burns, Trauma
What are some susceptibilities which may lead to AKI?
- Dehydration or volume depletion
- Advance age
- Female gender
- Black race
- Diabetes mellitus
What is prerenal AKI?
-Impaired blood flow to the kidneys resulting in decreased urine output and retention of N waste products
What causes prerenal AKI?
Hypovolemia due to haemorrhage, burns, diarrhea, vomiting, inadequate fluid replacement and decreased cardiac output
Dietary intervention in prerenal AKI?
Minimal dietary intervention req, will be resolved if underlying problem is treated
What is intrinsic AKI?
Damage within the kidney cells (kidney parenchyma or acute tubular necrosis)
What are the causes of intrinsic AKI?
- Exposure to toxins such as antibiotics, chemo, contrast dyes
- Systematic inflammatory conditions such as sepsis, acute infections (glomerulonephritis)
When is nutritional management critical?
During intrinsic AKI
What is postrenal (obstructive) AKI?
-Obstruction in the urine flow (UT obstruction)
Causes of postrenal AKI?
-Bladder cancer, benign prostate hyperplasia, strictures, blood clots, kidney stones
Dietary intervention in postrenal AKI?
Minimal, as issue will be resolved if underlying problem is corrected
How does KDIGO classify severity?
SCr and urine output
How does RFLE classify severity?
-Risk, injury, failure and loss of function
AKI Stage 1 Sr. Ceat?
-1.5-1.9 x baseline or >0.3 mg increase
AKI Stage 1 u/o?
<0.5 ml/kg 3 hr for 6-12 hours
AKI Stage 2 Sr. Cr?
2.0-2.9 x baseline
AKI Stage 2 u/o?
<0.5 ml/kg/ 3 hr for >12 hours
AKI Stage 3 Sr. Cr?
1) 3.0 x baseline
OR
2) >4 mg/dl increase in sr.cr
OR
3) Initiation of renal replacement therapy
OR
4) In patients <18 yrs, decrease in eGFR to <35 ml/min
Stage 3 AKI u/op?
1) <0.3 ml/kg/3h >24 hours
OT
2) Anuria for >12 hours
Symptoms and signs of AKI?
- fluid retention/overload
- Metabolic acidosis
- Electrolyte abnormalities
- Anemia
Which electrolytes are often high in AKI?
-K, Mg and Na
Complications of AKI
-hematuria
-reduced u/o
-dehydration
uremia
-side/lower back brain (obstructed urinary tract)
What are some metabolic complications of AKI?
- Decrease pro synth, increased breakdown
- Insulin resistance
- Azotemia
- Anemia
- HTN
- High TG/Cholesterol
AKI nutritional goals?
- Minimize uremia and maintain the chemical compostions of the body as close as possible
- Preserve LBM
- Maintain electorlyte/acid base homeostasis
- NS if indicated
General dietary guidelines for AKI?
- Controlled protein, phos, Na, K and fluid
- Energy to meet req and minimize LBM breakdown
- Consider supplementation of water soluble vitamins due to losses in dialysis
Energy in AKI?
25-30 kcal/kg based on ABW (IBW if obese)
Protein in AKI?
1.2-2 g/kg/day ABW
Protein in CRRT?
2.5 g/kg/day ABW
Minerals, electrolytes and trace elements?
Maintain serum level
Fluid requirements?
Output + 400-500 ml
What weight gain may indicate fluid retention?
Gain of >0.5-1kg/day could be fluids
What should be monitored in AKI?
- Daily intake/output
- Serum electrolytes
- BP
- Weight gain or loss
