{"title":"Méthémoglobinémie","authors":"","doi":"10.1016/j.revmed.2024.05.001","DOIUrl":null,"url":null,"abstract":"<div><p>Methemoglobinemia (MetHb) refers to the state of oxidation of the iron ion “ferrous” (Fe<sup>2+)</sup> to iron “ferric” (Fe<sup>3+</sup>) within the heme molecule that makes up hemoglobin (Hb). This state is physiological if its level remains controlled. The ferrous state of the heme molecule occurs in the event of significant oxidative stress. The pathophysiology of MetHb involves NADH, NADPH and glucose cycle enzymes such as cytochrome-b5-reductase. MetHb can be acquired or more rarely, congenital. Acquired causes include drug-induced effects such as topical anesthetics, or toxic effects such as nitrites. Primary causes are linked to enzyme deficiencies or constitutional Hb abnormalities. Excessively high MetHb causes symptoms of varying intensity, depending on the level of MetHb and associated comorbidities. Clinical signs are dominated by cyanosis, indicative of tissue hypoxia, which can be complicated by severe metabolic disorders leading to death. Diagnosis can be complex, as the resulting biological abnormalities may go undetected. Treatment is mainly based on identifying the etiology and restoring the heme molecule to its physiological state. Methylene blue is the main antidote in cases of elevated MetHb, but precautions must be taken in its use, and its physico-chemical effects must be understood. We provide an update on methemoglobinemia, summarizing its pathophysiology and clinical presentations, complementary tests and therapeutic principles.</p></div>","PeriodicalId":54458,"journal":{"name":"Revue De Medecine Interne","volume":null,"pages":null},"PeriodicalIF":0.7000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0248866324005630/pdfft?md5=de81a6fc38119fcc76a8250114a22320&pid=1-s2.0-S0248866324005630-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Revue De Medecine Interne","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0248866324005630","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MEDICINE, GENERAL & INTERNAL","Score":null,"Total":0}
引用次数: 0
Abstract
Methemoglobinemia (MetHb) refers to the state of oxidation of the iron ion “ferrous” (Fe2+) to iron “ferric” (Fe3+) within the heme molecule that makes up hemoglobin (Hb). This state is physiological if its level remains controlled. The ferrous state of the heme molecule occurs in the event of significant oxidative stress. The pathophysiology of MetHb involves NADH, NADPH and glucose cycle enzymes such as cytochrome-b5-reductase. MetHb can be acquired or more rarely, congenital. Acquired causes include drug-induced effects such as topical anesthetics, or toxic effects such as nitrites. Primary causes are linked to enzyme deficiencies or constitutional Hb abnormalities. Excessively high MetHb causes symptoms of varying intensity, depending on the level of MetHb and associated comorbidities. Clinical signs are dominated by cyanosis, indicative of tissue hypoxia, which can be complicated by severe metabolic disorders leading to death. Diagnosis can be complex, as the resulting biological abnormalities may go undetected. Treatment is mainly based on identifying the etiology and restoring the heme molecule to its physiological state. Methylene blue is the main antidote in cases of elevated MetHb, but precautions must be taken in its use, and its physico-chemical effects must be understood. We provide an update on methemoglobinemia, summarizing its pathophysiology and clinical presentations, complementary tests and therapeutic principles.
期刊介绍:
Official journal of the SNFMI, La revue de medecine interne is indexed in the most prestigious databases. It is the most efficient French language journal available for internal medicine specialists who want to expand their knowledge and skills beyond their own discipline. It is also the main French language international medium for French research works. The journal publishes each month editorials, original articles, review articles, short communications, etc. These articles address the fundamental and innumerable facets of internal medicine, spanning all medical specialties. Manuscripts may be submitted in French or in English.
La revue de medecine interne also includes additional issues publishing the proceedings of the two annual French meetings of internal medicine (June and December), as well as thematic issues.