Lidocaine-induced methemoglobinemia: A clinical reminder

Abstract

Methemoglobinemia is a rare condition in which the iron in hemoglobin is stabilized in the ferric (Fe3+) form, making it unable to bind oxygen and leading to tissue hypoxia and pos-sibly death. The condition may be hereditary or acquired, the latter resulting from ingestion or application of common oxidizing agents such as lidocaine. As management of methemoglobinemia depends on prompt recogni-tion, clinicians who administer or prescribe oxidizing agents must be aware of the clinical symptoms of methemoglobinemia, including cyanosis, pulse oximetry values that do not respond to increased oxygen delivery, and al-tered mental status. Currently, methylene blue is the drug of choice for the management of methemoglobinemia.