Delayed admission for ethylene glycol poisoning: lack of elevated serum osmol gap

In the absence of an immediately available serum ethylene glycol (EG) assay , the diagnosis of EG poisoning is usually based on anamnesis, clinical fin dings and presence of metabolic acidosis with elevated serum anion gap, ele vated serum osmol gap, hypocalcemia and crystalluria. We report two cases o f EG poisoning, both presenting without an elevated serum osmol gap and we discuss conditions which facilitate such a presentation, especially delayed hospital admission. Finally, we confirm the fact that determination of the osmol gap can fail as a screen for EG poisoning.