Acquired methemoglobinemia after application of prilocaine

Abstract

Prilocaine is a local anesthetic agent and is widely used in most of ambulatory procedures, but it can cause methemoglobinemia which is a life-threatening condition. Methemoglobinemia may cause hypoxia of tissue because methemoglobin has less oxygen carrying capability than hemoglobin. A 54-day-old boy who developed cyanosis around his mouth, on his hands and toes two hours after the circumcision operation was admitted to the emergency department. No abnormality was established on his physical examination except for cyanosis. Cyanosis did not improve with oxygen administration and the patient was admitted to intensive care unit. His history revealed that prilocaine hydrochloride (2 mg/kg) was administered subcutaneously as local anesthesia prior to circumcision operation. Diagnosis of methemoglobinemia was established in the patient in whom saturation levels were low in spite of the oxygen therapy and in whom methemoglobinemia level was 24.7%. His cyanosis completely disappeared after administration of intravenous ascorbic acid (300 mg/kg/dose) and he was discharged after a 24-hour follow-up period with recovery. Methemoglobinemia should be considered in cases with cyanosis and inconsistency between oxygen saturation and partial arterial oxygen pressure. These cases should be monitored in pediatric intensive care units for lethal complications.