Acute Kidney Injury / Failure Flashcards
General pre-renal fast facts
Hypoperfused kidneys from shock, volume depletion, diuretics, or third spacing.
UNa 20:1
Hyaline casts
Uosm >500 bc of inc ADH to conserve H2O
Hepatorenal syndrome fast facts
Cirrhosis leads to portal hypertension, decreasing ECFV and increasing RAAS and renal Na absorption/VASOCONSTRICTION.
Pres: hypotensive despite inc ECFV
UNa <10
DDx: try volume infusion to see if corrects
Bilateral renal artery stenosis - how can patients with it get AKI?
When on ACE inhibitors
Bilateral artery stenosis w/ ACEi fast facts
Low ATII prevents efferent constriction to regulate GFR and RPF
Take off of ACEi
Pre-renal failure with NSAID use fast facts
Lack of PGs means no afferent arteriole dilation, causing inc RPF
Leads to AKI in pts with volume depletion, CHF, cirrhosis
Take them off of NSAIDs
COX2 inhibitors do this too
Intra-renal fast facts and locations
Structural defect/damage within kidney causes loss of function
Glomerular
Tubular
Vascular
Acute tubular necrosis fast facts
Due to diffuse ischemia or toxic injury (contrast, lead, etc.)
Energy-dep parts of tubule (thkALH & PT) die and shed cells into urine–>MUDDY BROWN GRANULAR CASTS
UNa >20
FeNa >1%
Tx: dialysis, supportive, avoid nephrotoxins
Intra-renal from therapeutic agents fast facts
Ampho B, AMINOGLYCOSIDES accum in prox tubule and inhibit lysosome fxn
-OR-
Contrast causes vasoconstriction/toxicity
Pres 2-3 days after contrast or antibiotics
prevent with 1/day amino glycosides and treating hypovolemia before doing image
Acute interstitial nephritis fast facts
Allergic reaction to penicillins/cephalosporins, NSAIDs 3-4 days after administration that causes granulocyte infiltration of kidneys, esp. eosinophils
Pres: fever, rash, joint pain, eos on CBC
Rule out obstruction with Foleys and ultrasound
