Specimen Name Result Units Range
Plasma Sodium 138 mmol/L (135-145)
Potassium 3.9 mmol/L (3.5-5.5)
Chloride 98 mmol/L (100-109)
Bicarbonate 23 mmol/L (22-32)
Urea 16.0 mmol/L (2.7-7.2)
Creatinine 210 μmol/L (60-110)
Osmolality 297 mmol/kg (275-295)
Urine Sodium 51 mmol/L (> 20)
Osmolality 560 mmol/kg
Creatinine 10,700 μmol/L

40yo male with vomiting, diarrhoea & oliguria ≤ 10 mL/hr.
Dehydration : Pre-Renal AKI / Oliguria

High urinary Na+ suggests ATN, however:

  • urine:plasma osmolality > 1.3
  • urine:plasma creatinine > 14
  • FE[Na] < 1.0

    • **suggesting ≈ normal renal concentrating mechanisms.