Co-ingestion of methanol and nitromethane: using falsely elevated creatinine as indicator for methanol antidote use.

Objective: To report a case of co-ingestion of methanol and nitromethane in a child in order to heighten the awareness of false elevation of serum creatinine from nitromethane ingestion.

Design: Case report.

Setting: Pediatric intensive care unit.

Patient: A 4-yr-old previously healthy girl ingested an unknown quantity of "Blue Thunder" model-engine fuel, which consisted of methanol and nitromethane. The patient was treated with fomepizole for methanol ingestion using elevated creatinine level as a reason for treatment.

Results: The patient was asymptomatic but her creatinine level increased ten-fold (from 0.4 mg/dL to 4 mg/dL) within 6 hrs. Blood urea nitrogen, anion gap, and osmolar gap remained within normal limits. When the serum creatinine level was measured with enzymatic method instead of Jaffe's method, a normal creatinine level was obtained. The falsely elevated creatinine level was due to nitromethane.

Conclusion: The falsely elevated serum creatinine levels due to nitromethane ingestion can lead to unnecessary therapeutic interventions. We intend to heighten awareness of this potential misstep by reporting this case.