An unusual case of toluene-induced metabolic acidosis

We used gas chromatography-mass spectrometry to analyze serum specimens from a patient whose metabolic ketoacidosis resulted from sniffing a toluene-containing substance; we also analyzed a sample of the abused substance itself and a serum specimen from a normal subject. The blood samples from the patient showed abnormally high concentrations of acetoacetic, azelaic, benzoic, and 3-hydroxybutyric acids, and a smaller amount of hippuric acid than in the control serum. The ketone bodies and benzoic acid appeared to be factors contributing to her acidosis and ketosis. Analysis for volatile solvents in the patient's serum revealed a low concentration of methyl acetate, in contrast to the high concentrations of toluene and bis(2-ethylhexyl) phthalate and the trace concentration of xylene in the abused substance. We consider this case unusual because the presence and concentration of specific ketoacids was unexpected in light of what was known about the patient.