Multiorgan Failure Secondary to Intentional Acetaminophen Overdose-Induced Methemoglobinemia

Although acetaminophen toxicity has been reported to cause methemoglobinemia, its recognition remains limited in the clinical literature. Methemoglobinemia often necessitates a high index of clinical suspicion, as it may contribute to lactic acidosis and multiorgan dysfunction due to impaired tissue oxygenation. A 21-year-old man presented to the emergency department (ED) via emergency medical services (EMS) with reports of an intentional overdose of an unknown amount of bupropion, two pill bottles of acetaminophen, and an unknown amount of bleach. The patient was emergently intubated. Despite reported bleach ingestion, esophagogastroduodenoscopy (EGD) revealed no evidence of caustic injury or esophagitis. The poison center was contacted, and the patient was started on N-acetylcysteine (NAC). The exact time of acetaminophen ingestion was unknown; however, liver function tests were normal at presentation. Transaminases became abnormal 48 hours later (well after NAC administration had begun). Persistent lactic acidosis in the context of normal initial transaminase levels raised clinical suspicion for methemoglobinemia, given the potential for tissue hypoxia. Methemoglobin levels were confirmed to be elevated, potentially explaining tissue ischemia. The patient received methylene blue as the antidote. The liver transplant team was consulted and agreed with the poison center's recommendation of excluding acetaminophen-induced liver injury. Due to unexplained elevated lactic acid and multisystem organ failure, the family elected for a Do Not Resuscitate (DNR) status. The patient expired four days later with multisystem organ failure.