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

  • inadequate fluid intake - hypertonic urine
  • extrarenal fluid loss - vomiting, diarrhoea, fistulae
  • diabetes insipidus - hypotonic urine

Note : Could also suggest impaired renal concentrating ability:

  • osmolality : [plasma] > 320 → [urine] ≈ [urine]max1200-1400mmol/kg
  • though, at age 75 [urine]max will be lower.

H2O Deficit Estimation