AKI Flashcards
What are the KDIGO criteria for an AKI?
- increased serum creatinine by > 0.3 mg/dL within 48 hrs
- increase in serum creatinine by > 1.5x baseline (must be a known or presumed value within the last 7 days)
- urine volume < 0.5 mL/kg/h for 6 hours
How do AKIs affect extracellular volume? What are the systemic effects of this?
They lead to extracellular volume expansion; this causes hypertension, CHF, pulmonary/peripheral edema
AKI can lead to ____kalemia
AKI can lead to hyperkalemia
AKI can lead metabolic _____osis
AKI can lead to metabolic acidosis
AKI can lead to _____phosphatemia
AKI can lead to hyperphosphatemia
What are four categories of pre-renal AKIs?
- decreased CO
- hypovolemia
- peripheral vasodilation
- selective renal ischemia
What is the definition of a pre-renal AKI?
A reduction in the GFR as a result of decreased renal perfusion that is reversed with restoration of perfusion and is not associated with structural kidney damage
What is the expected BUN/Creatinine ratio in pre-renal AKI?
> 20 (indicates hypoperfusion of the kidneys and reduced BUN reabsorption)
What is the expected FENa associated with pre-renal AKI?
< 1% (aka the kidneys are responding normally to decreased renal perfusion and thus are not damaged)
What is the FENa associated with acute tubular necrosis?
> 2%
What is the expected urine sodium associated with pre-renal AKI?
< 20 mmol/L (low)
What is the mechanism of AKI associated with acute tubular necrosis?
Reduced renal blood flow due to ischemia or nephrotoxicity leads to tubular injury and casts obstructing urine
What types of urine sediments are associated with ATN?
Muddy brown casts
What urine sediments are associated with acute interstitial nephritis?
WBC casts, eosinophils in urine
What urine sediments suggest a glomerularnephritic etiology of AKI?
RBC casts
