List 3 causes for the following combination of findings observed on a serum sample.
Test |
Value |
Normal Range |
Measured osmolality* |
340 mOsm/kg |
(280 – 290) |
Sodium |
138 mmol/L |
(135 – 145) |
Potassium |
4 mmol/L |
(3.5 – 5.0) |
Chloride |
98 mmol/L |
(95 – 105) |
Bicarbonate* |
15 mmol/L |
(22 – 32) |
Glucose |
6 mmol/L |
(4 – 6) |
Urea |
8 mmol/L |
(6 – 8) |
• Raised osmolar gap with raised AG
• Methanol
• Ethylene glycol
• Ethanol
• Lactic acidosis can lead to a raised OG and AG, however, the osmolar gap does not reach the levels seen here.
These biochemistry results are provided without any history.
Let us dissect them systematically.
Thus, this high anion gap metabolic acidosis is also associated with a raised osmolar gap.
Most likely differentials:
Less likely differentials (osmolar gap is probably a bit too high for these to be realistic differentials):
Jacobsen, Dag, et al. "Anion and osmolal gaps in the diagnosis of methanol and ethylene glycol poisoning." Acta Medica Scandinavica 212.1‐2 (1982): 17-20.