Methemoglobinemia after Intravenous Lidocaine for Rapid Sequence Intubation

Lidocaine is widely used during rapid sequence intubation to decrease the airway resistance and intracranial pressure that occur in general anesthesia. Common side effects of lidocaine include arrhythmia, agitation and bronchospasm. Although lidocaine induced methemoglobinemia tends to be clinically insignificant, it does carry the risk of life threatening hypoxemic respiratory failure. Herein we report a 38-year-old woman who developed acute methemoglobinemia after intravenous lidocaine administration during rapid sequence intubation. Her methemoglobin level reduced and cyanosis resolved after intravenous methylene blue infusion (a total of 3 mg/kg). A discrepancy in pulse oximetry and the blood gas analysis result is the hallmark of this treatable, but life-threatening clinical condition and should be recognized for a timely treatment.