Specimen Name Result Units Range
Plasma Sodium 115 mmol/L (135-145)
Potassium 2.4 mmol/L (3.5-5.5)
Chloride 40 mmol/L (100-109)
Bicarbonate 26 mmol/L (22-32)
Anion Gap 51 mmol/L (7-17)
Glucose 99 mmol/L (3.8-5.5)
Urea 12.3 mmol/L (2.7-7.2)
Creatinine 300 μmol/L (60-110)
Urea/Creat Ratio 41 (35-80)
Osmolality 347 mmol/kg (275-295)
Albumin 36 g/L (34-48)
Total Bilirubin 19 μmol/L (6-24)
GGT 99 U/L (< 60)
ALP 205 U/L (30-110)
AST 18 U/L (< 45)
Lactate 18 mmol/L (< 1.3)
Amylase 71 U/L (20-100)
Beta-hydroxybutyrate 0.33 mmol/L (< 0.09)
Acetoacetate 0.00 mmol/L (< 0.3)
Blood Alcohol 0.00 g/dL (%) (< 0.05)
ABG pH 7.42 (7.36-7.44)
PaO2 43 mmHg (70-100)
PaCO2 57 mmHg (35-45)
HCO3- 38 mmol/L (21-26)

Male 42yo collapsed in the street.

PHx: CAL

Depressed CNS but able to respond to questioning. BP ≈ 60/-
Hyperglycaemic Non-ketotic Coma
  • Hyperglycaemia → diabetic disorder
  • Hyperosmolar 'hyponatraemia' : corrected [Na+] ≈ 145 mmol/L
  • Metabolic ↑AG acidosis : major component ∝ lactate
    • ↑AG ≈ 38 > ↓HCO3- ≈ 21
    • ∴ minimal renal HCO3- loss
    • ??cause ∝ hypovolaemic shock, hypoxaemia
    • all ketones → β-OH-B due to low redox state
      i.e. a marked lactic acidosis will mask a small ketosis where only Ac-Ac is tested.
  • Significant hypoxaemia ∝ aspirated vomitus
  • Pre-renal failure : likely hypovolaemia → U/C ratio ≈ 63

Complicated biochemical picture:

  • pre-existing metabolic alkalosis ∝ ?COPD, alkali ingestion
  • marked hypercalcaemia (not shown) 2° acidosis & liberation from bone
    → normalized by day 4
  • respiratory acidosis ∝ CNS depression / aspiration pneumonitis

 

Hyperosmolar Hyponatraemia:

  1. Glucose
    • DKA, HONC
    • 'Corrected' [Na+] ≈ [Na+]Pl + [BGL-10]/3
  2. Urea:
    • esp. salt-losing nephritis
    • high [K+], creatinine, urea
  3. Others:
    • mannitol
    • glycine port-TURP
    • glycerol, sorbitol, ethanol, methanol

Differential:

  • IVT arm sample - normal osmolality
  • salt-losing nephritis - normal BGL, no ketones