Acute Kidney Injury

Nephrology

Abrupt decline in kidney function — KDIGO ≥0.3 mg/dL Cr rise in 48 h, ≥1.5× baseline in 7 d, or oliguria.

Causes

  • Pre-renal: hypovolaemia, sepsis, HF, NSAID/ACEi
  • Renal: ATN, GN, interstitial nephritis, contrast
  • Post-renal: obstruction

Investigations

  • U&E, urinalysis (blood, protein, casts)
  • USS renal tract (urgent if obstruction)
  • FENa, urine Na, osmolality
  • Bloods: FBC, CK, immunology if intrinsic

Management

  • Stop nephrotoxins (NSAID, ACEi/ARB, gent)
  • Optimise volume + perfusion
  • Relieve obstruction (catheter, nephrostomy)
  • Treat cause; RRT if AEIOU criteria

Complications

  • Hyperkalaemia, acidosis, fluid overload
  • CKD progression

Clinical pearls

  • AEIOU for dialysis: Acidosis, Electrolytes (K), Intoxication, Overload, Uraemia
  • Urine output is the cheapest monitoring tool

Educational — verify locally.

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WardRound

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