PSEUDO-NORMAL OSMOLAL AND ANION GAPS FOLLOWING SIMULTANEOUS ETHANOL AND METHANOL INGESTION

Methanol, ethylene glycol, and isopropyl alcohol are associated with a cute intoxication. The diagnosis is dependent upon high anion-gap meta bolic acidosis, and an osmolal gap between the calculated and the meas ured osmolality. Normal anion gap has been reported in some cases of c oncomitant methanol and ethanol ingestion, where the high serum levels of ethanol inhibited the metabolism of methanol by alcohol dehydrogen ase. The osmolal gap in these cases was higher than expected for metha nol, and served as a constant marker for a metabolic derangement. Here with, we present a patient who presented with normal osmolal and anion gaps 36 h after ethanol and methanol ingestion, yet progressively dev eloping ocular toxicity. Normal anion and osmolal gaps should not rule out earlier methanol poisoning.