AKI Flashcards
AKI
Sudden decrease/impairment in renal function
Kidney Risk
Increase Cr x1.5 or GFR >25%
UO < 0.5ml/kg/hr x 6 hours
Kidney Injury
Increase Cr x 2 or decrease GFR >50%
UO < 0.5ml/kg/hr for 12 hours
Kidney Failure
Increase Cr x3 or decrease GFR >75%
UO < 0.3ml/kg/hr x 24 hours or Anura x 12 hours
Kidney Loss
Complete loss of kidney function > 4 weeks
ESKD
Complete loss of kidney function > 3 months
Prerenal
Causes by conditions that impair renal perfusion such as shock, dehydration, cardiac failur, burns, diarrhea, vasodilation/sepsis
Only if it is reversed when the underlying caused of hypoperfusion is corrected
No damage to renal tubules
Intrarenal
Caused by disorders that directly affect the renal cortex or medulla such as hypersensitive (allergic disorders, obstruction of renal vessels (embolism or thrombosis)
** Nephrotoxic agents most common cause
Mismatched blood transfusions
Results in nephron damage: Damage to the tubular portion of the nephron is the most common cause (acute tubular necrosis)
Post Renal
Results in urine flow obstruction
Causes:
Mechanical: Calculi, tumors, urethral stricture, BPH
Functional: Neurogenic bladder, diabetic neuropathy
PreRenal Lab/Diagnostics
BUN:Cr Ratio >10:1 Urine sodium <20 SG >1.015 Urine Sediment Normal FENa <1
Intrarenal Lab/Diagnostics
BUN:Cr Ratio 10:1 Urine Sodium >40 SG <1.015 Urinary sediment: granular/ white casts FENa >3
PostRenal Lab/Diagnostics
BUN: Cr Ratio 10:1 Urine sodium: usually >40 SG <1.015 Urinary Sediment: normal FENa: usually >3
AKI Management
Prerenal: Expand intravascular volum
Intrarenal: Maintain renal perfusion, stop nephrotoxic drugs, renal replacement therapies as indicated
PostRenal: Remove source of obstruction - check foley, renal US, CT
Criteria for Dialysis
A: Acidosis (metabolic) E: Electrolyte imbalances I: Intoxication (personality change) O: Oliguria (UO<400ml/24 hours) Anuria < 100/24hrs U: Uremia
