Severe Methemoglobinemia With Unknown Cause – Case Report

Abstract

The aim: Methemoglobina is an oxidized form of hemoglobin, which normally doesn`t exceed 1%. It is stated that the amount of methemoglobin over 70% is fatal. The etiology vary, it might for instance be idiopathic, congenital or caused by toxic compounds. Material and methods: We analyzed the case of patient who had exceeded the fatal level of methemoglobin in a blood. Case report: Medical Air Rescue Team was dispatched to an 80-year-old patient who suddenly lost consciousness at home. Methemoglobin level was measured using Cobas b221 system and amounted to 75%. Given the patient’s advanced age, congenital causes of methemoglobinemia, such as deficiency of cytochrome-b5 reductase or nicotinamide adenine dinucleotide reductase (NADPH-MHb reductase) were excluded a priori. It seems that the only reason for the observed methemoglobinemia in the case of the examined patient was the acquired methemoglobinemia. The patient was treated with methylene blue with good results, her state improved soon. Despite a detailed interview, it was impossible to establish the etiological factor of methemoglobinemia. None of the household members exhibited clinical symptoms of poisoning with methemoglobinogenic substance. Although the methemoglobin level was potentially deadly, the patients survived. Conclusion: It should be stressed that it is not always possible to determine the etiological factor of the discussed disorders. Knowledge of the clinical picture of poisoning, as well as of the changes characteristic for poisoning and observable in laboratory, is extremely important, especially when it is not possible to determine the etiological factor of poisoning.