Renal function

Fractional excretion of Na (FENa)

Pre-renal vs intrinsic AKI distinction. Not reliable on diuretics — use FEUrea.

AKIpre-renal

Required inputs

  • Urine Na mEq/L
  • Serum Na mEq/L
  • Urine creatinine
  • Serum creatinine

Equation or source

Espinel CH. JAMA 1976;236:579.

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