TY - CHAP M1 - Book, Section TI - Methemoglobinemia and Other Dyshemoglobinemias A1 - Agarwal, Archana M. A1 - Prchal, Josef  T. A2 - Kaushansky, Kenneth A2 - Lichtman, Marshall A. A2 - Prchal, Josef T. A2 - Levi, Marcel M. A2 - Press, Oliver W. A2 - Burns, Linda J. A2 - Caligiuri, Michael Y1 - 2015 N1 - T2 - Williams Hematology, 9e AB - SUMMARYNormal hemoglobin can be oxidized to methemoglobin. Methemoglobinemia occurs because of either increased production of oxidized hemoglobin from exposure to environmental agents or diminished reduction of oxidized hemoglobin because of underlying germline mutations. Cyanosis is virtually invariant in patients with methemoglobinemia. Hemoglobin can also bind carbon monoxide and nitric oxide, resulting in the formation of carboxyhemoglobin and nitrosohemoglobin. Sulfhemoglobinemia occurs because of increased production secondary to occupational exposure to sulphur compounds or exposure to oxidant medications. These modified hemoglobins are known as dyshemoglobins. Depending upon the severity and individual predisposition, presence of dyshemoglobins can result in varying degree of clinical manifestations. Prompt diagnosis is the key to effective and timely treatment. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1121094261 ER -