Severe methemoglobinemia caused by continuous lidocaine infusion in a term neonate.

Neonates and young infants are especially prone to develop drug-induced methemoglobinemia. Therefore, lidocaine is not licensed as local anesthetic in children below the age of 3 months. However, its systemic use is advocated for neonatal seizures. Cardiac arrhythmia has been reported as sole major side effect. Here we report a case of severe methemoglobinemia caused by continuous infusion of lidocaine in a term neonate with neonatal seizures. The increase of methemoglobin up to 13.8% was accompanied by hypoxemia and cyanosis, necessitating additional inspired oxygen and CPAP ventilation. After stopping lidocaine infusion methemoglobin levels fell and the neonate could be weaned from ventilation. Neonates treated with lidocaine for seizures must be monitored for the occurrence of methemoglobinemia.