Published Paper Details:

Methemoglobinemia (MetHb) is a rare yet significant condition characterized by the unusual accumulation of methemoglobin, an oxidized hemoglobin form that compromises its oxygen transport function. This review comprehensively elucidates MetHb, surrounding its etiological factors, pathophysiological mechanisms, clinical manifestations, diagnostic modalities and therapeutic interventions. The review delineates the diverse causative agents of MetHb, spanning genetic predispositions to exposure to specific pharmaceuticals, chemicals and toxins, with particular emphasis on well-documented substances such as nitrates and aniline derivatives. Additionally the propensity of individuals with methemoglobin reductase deficiencies is discussed. The review further explores the genetic and acquired determinants contributing to MetHb, highlighting the importance of red blood cell metabolism and hemoglobin structure in its genesis. Clinical aspects of MetHb are expounded, ranging from asymptomatic presentations to severe symptoms, including cyanosis, dyspnea, and cardiac arrhythmias leading to circulatory failure in critical scenarios. Remarkably, children with congenital heart diseases and MetHb often manifest ambiguous oxygen saturation readings, accentuating the clinical complexities associated with this condition. Various therapeutic strategies for MetHb are scrutinized, encompassing the use of methylene blue, ascorbic acid and N-acetylcysteine. A relative analysis of these treatment modalities is presented, incorporating dosing recommendations and potential side effects. Moreover, recent advancements in research methodologies, such as Broadband Diffuse Optical Spectroscopy and Photoacoustic Microscopy, are discussed for their contributions to comprehending methemoglobin formation and reduction in animal models. These non-invasive techniques afford real-time monitoring of methemoglobin levels, furnishing valuable insights into the dynamic nature of the disease. In conclusion, this review offers an in-depth exploration of MetHb, elucidating its comprehensive etiology, varied clinical presentations and evolving therapeutic approaches. The insights provided herein serve as a valuable guide for healthcare professionals in effectively managing this elaborate condition.