333.2 🩺 國考版

333.2.1 高頻考點

333.2.1.1 KDIGO 2012 AKI Definition (MEMORIZE)

  • ↑ SCr ≥ 0.3 mg/dL in 48 h
  • ↑ SCr ≥ 1.5× baseline in 7 d
  • UO < 0.5 mL/kg/h × 6 h

333.2.1.2 Pre-Renal AKI

  • BUN/Cr > 20:1
  • FENa < 1%
  • U Na < 20
  • U Osm > 500 (concentrated urine)
  • Hyaline casts
  • Reversible with volume

333.2.1.3 ATN

  • BUN/Cr < 20
  • FENa > 2%
  • U Na > 40
  • U Osm 300-350 (isothenuric)
  • Muddy brown granular casts
  • Tubular epithelial cells

333.2.1.4 Common ATN Drugs

  • Aminoglycosides
  • Vancomycin
  • Contrast
  • Cisplatin, ifosfamide
  • Tenofovir
  • Amphotericin B
  • Calcineurin inhibitors

333.2.1.5 AIN (Acute Interstitial Nephritis)

  • Drugs (PPI, NSAID, penicillin, ICI)
  • Eosinophilia
  • WBC casts, urine eosinophils
  • Fever, rash variable

333.2.1.6 Common AIN Drugs

  • Penicillins, cephalosporins
  • NSAIDs
  • PPIs
  • Sulfonamides
  • Allopurinol
  • ICIs (pembrolizumab, etc.)

333.2.1.7 Post-Renal AKI

  • Obstruction (bilateral or solitary kidney)
  • US: hydronephrosis
  • BPH, stones, malignancy, retroperitoneal fibrosis

333.2.1.8 FENa Calculation

  • FENa = (UNa × PCr) / (PNa × UCr) × 100
  • < 1% pre-renal

  • 2% ATN

  • Less reliable in CKD, diuretics, sepsis early
  • FEUrea more useful on diuretics (< 35% pre-renal)

333.2.1.9 Hepatorenal Syndrome

  • Cirrhosis + AKI, no other cause
  • Terlipressin + albumin (FDA 2022)
  • Norepinephrine + albumin
  • Liver transplant definitive

333.2.1.10 Rhabdomyolysis

  • CK > 5000
  • Myoglobin tubular obstruction + toxicity
  • Aggressive IV fluids
  • Urine output > 200-300 mL/h target

333.2.1.11 TLS

  • Hyperuricemia + hyperphosphatemia + hyperkalemia + hypocalcemia
  • AML, ALL, lymphoma at risk
  • Rasburicase for severe

333.2.1.12 Contrast-Associated AKI

  • Within 24-48 h post-contrast
  • Hydration prevention
  • Incidence lower with modern contrast

333.2.2 易混淆比范

Type BUN/Cr FENa U Na U Osm Sediment
Pre-renal > 20 < 1% < 20 > 500 Bland, hyaline
ATN < 20 > 2% > 40 300-350 Muddy brown granular
AIN Variable Variable Variable Variable WBC casts, eosinophils
GN Variable Variable Variable Variable RBC casts, dysmorphic RBC
Obstruction Variable Variable Variable Variable Variable; hydronephrosis on US

333.2.3 Special Topics

333.2.3.1 CIN vs PC-AKI vs CA-AKI

  • Contrast-induced nephropathy (CIN): historical
  • Post-contrast AKI (PC-AKI): temporal
  • Contrast-associated AKI (CA-AKI): current term
  • Causality less certain than thought
  • Modern low-osmolar / iso-osmolar contrast safer

333.2.3.2 Sepsis-AKI Pathophysiology

  • Not just hypoperfusion
  • Microcirculatory dysfunction
  • Tubular cell stress (not necrosis classically)
  • Cytokines, immune