Diagnosis and misdiagnosis of poisoning with the cyanide precursor acetonitrile: nail polish remover or nail glue remover?

Accurate diagnosis of acetonitrile ingestion is critical to management. Often this involves differentiating nail polish remover (acetone) from nail glue remover (acetonitrile). Initial symptoms of acetonitrile ingestion are indistinguishable from those of acetone and common alcohols. However, acetonitrile is metabolized to cyanide, producing severe delayed toxicity. Acetonitrile produced increased serum osmolality and osmolal gap, but these findings are non-specific and normal values cannot rule out potentially fatal exposure. Acetone, but not acetonitrile, was detectable in urine or serum with Acetest tablets; both were unreactive with a ketone dipstick. Acetone and acetonitrile could be detected with routine gas chromatography methods for alcohols. Both substances had identical retention times on the widely used stationary phase, 5% Carbowax 20M on graphitized carbon, and with GasChrom 254. Three other systems afforded unique retention times, but acetonitrile was easily mistaken for ethanol in two. Physicians and laboratories must take care to avoid misdiagnosis of acetonitrile ingestion as exposure to acetone, ethanol or another alcohol.