The most likely diagnosis is pyroglutamic acidosis. Pyroglutamic acidosis, which presents with mental status changes and an increased anion gap, occurs in selected patients receiving therapeutic doses of acetaminophen on a chronic basis. Susceptible patients are those with critical illness, poor nutrition, liver disease, or chronic kidney disease, as well as those on a strict vegetarian diet. In this context, acetaminophen leads to depletion of glutathione, altering the γ-glutamyl cycle to overproduce pyroglutamic acid (also known as 5-oxoproline). Diagnosis can be confirmed by measuring urine levels of pyroglutamic acid.
