Methanol toxicity secondary to inhalant abuse in adult men

Abstract

Background. The purpose of this report is to evaluate the presentation, treatment, and outcomes of adults with methanol toxicity from inhalation of carburetor cleaning fluid fumes. Methods. Retrospective chart review of adults with positive serum volatile screen for methanol and history of carburetor cleaning fluid fume inhalation. Results. Sixteen patients were admitted 68 times. Eleven Native American patients accounted for 90% of admissions. Sixty-five cases presented with nausea/vomiting; 27 with intoxication or altered mental status; 21 with specific visual complaints. About 93% had a pH <7.35, 96% had serum bicarbonate <20 mEq/L, 81% had osmolal gap ≥10 mOsm/L, and 69% had anion gap >16. Ten had an initial serum methanol level <20 mg/dL, 29 cases 20–49 mg/dL, 19 cases ≥50 mg/dL. Six patients had a measurable serum ethanol level. Of the 29 patients with a methanol level of 20–49 mg/dL, 20 received intravenous antidote (ethanol or fomepizole); three received an antidote and hemodialysis. All who presented with a serum methanol level ≥50 mg/dL received intravenous ethanol or fomepizole. All visual symptoms resolved before discharge and all patients survived without sequelae. Discussion. This is the largest reported number of cases of methanol toxicity from the inhalation of carburetor cleaning fluid fumes and demonstrates a problem with recurrent abuse among some older Native American men. Conclusion. Intentional inhalation of methanol fumes may produce toxicity. Clinicians need to question patients, especially older Native American men, regarding the possible inhalation of carburetor cleaning fluid fumes in those who present with an unexplained metabolic anion gap acidosis.