Context: Manganese-associated parkinsonism is well described in occupational settings, in chronic methcathinone users, and in patients receiving long-term total parenteral nutrition. We present a unique case of acute intravenous manganese poisoning with a systematic evaluation of hemodialysis efficacy.
Case details: A 52-year-old woman was inadvertently administered a single intravenous dose of 800 mg compounded manganese chloride at an outpatient chelation center. In an attempt to minimize central nervous system (CNS) manganese deposition, she underwent urgent hemodialysis followed by five days of therapy with calcium disodium EDTA (1 g/m(2) over eight hours daily). Her initial whole blood manganese concentration, obtained six hours after exposure and prior to treatment, was 120 mcg/L (2.19 micromol/L); normal <5 mcg/L (< 0.09 micromol/L). Following the first four-hour hemodialysis session her blood manganese concentration decreased to 20 mcg/L (0.36 micromol/L). Despite the fall in her blood manganese concentration, analysis of dialysate revealed a total elimination of only 604 mcg (11 micromol) manganese (∼1.4% of manganese burden). Although she remained asymptomatic, an MRI on hospital day two revealed T1 hyperintensities within the bilateral globus pallidi, consistent with manganese exposure.
Discussion: Manganese poisoning is associated with irreversible neurologic toxicity. Hemodialysis did not appear to significantly enhance elimination in this case of acute intravenous manganese toxicity, beyond supportive care and calcium disodium EDTA chelation.
Keywords: Adverse drug event; compounding; hemodialysis; manganese; parkinsonism.