Specimen Name Result Units Range

Plasma Sodium 157 mmol/L (135-145)
Potassium 4.8 mmol/L (3.5-5.5)
Chloride 126 mmol/L (100-109)
Bicarbonate 26 mmol/L (22-32)
Anion Gap 10 mmol/L (7-17)
Glucose 5.4 mmol/L (3.8-5.5)
Urea 4.1 mmol/L (2.7-7.2)
Creatinine 100 μmol/L (60-110)
Osmolality 322 mmol/kg (275-295)

Urine Sodium 75 mmol/L (> 20)
Osmolality 678 mmol/kg

33yo female.

Longstanding psych. issues, with multiple admissions ∝ O/D


Exogenous NaCl Ingestion
  • hypernatraemia usually seen with uraemia ∝ hypovolaemia
  • normal urea suggests normovolaemia
  • ∴ possible causes:
    • IVT with hypertonic NaCL
    • IVT with N-saline & ongoing H2O losses
    • drugs with high salt load - NaHCO3, ABx (beta-lactams)
    • mineralocorticoid excess → usually with hypokalaemic alkalosis
      ** unlikely as urinary [Na+] would be low
    • TPN