Specimen Name Result Units Range
Plasma Sodium 153 mmol/L (135-145)
Potassium 3.7 mmol/L (3.5-5.5)
Chloride 117 mmol/L (100-109)
Bicarbonate 27 mmol/L (22-32)
Anion Gap 12 mmol/L (7-17)
Glucose 5.0 mmol/L (3.8-5.5)
Urea 15.0 mmol/L (2.7-7.2)
Creatinine 180 μmol/L (60-110)
Osmolality 326 mmol/kg (275-295)
Urine Sodium 12 mmol/L (> 20)
Osmolality 620 mmol/kg
Creatinine 10 μmol/L

Comatose 75yo female.
Dehydration : Pre-Renal AKI
  • Hyperosmolar hypernatraemia

 

Hypernatraemia & uraemia suggests hypovolaemia

  • extrarenal fluid loss:
    • ∝ vomiting, diarrhoea, fistulae
    • + inadequate fluid intake → hypertonic urine
  • renal fluid loss:
    • diabetes insipidus → hypotonic urine
    • polyuric renal failure → ≈ isotonic urine

 

Note : Could suggest impaired renal concentrating ability:

  • osmolality : [plasma] > 320 → [urine] ≈ [urine]max ≈ 1200-1400mmol/kg
  • though, at age 75 [urine]max will be lower.

 

H2O Deficit Estimation