Causa inusual de cianosis en el recién nacido: hemoglobina M / Unusual cause of cyanosis in the newborn: hemoglobin M

Resumen La hemoglobina M es un desorden hereditario infrecuente, causante de metahemoglobinemia y, por ende, cianosis. Las manifestaciones clínicas de esta enfermedad son amplias y variadas, por lo que se debe considerar como diagnóstico diferencial en un recién nacido con cianosis sin otra causa aparente. A continuación, se presenta el caso de un recién nacido de 5 horas de vida con cianosis generalizada desde el nacimiento y con saturaciones de oxígeno de entre 60-70%, en el que se descartaron patologías como hipoxia perinatal, patología pulmonar o cardíaca y sepsis y se documentó un nivel de metahemoglobina elevado, reportado en 21,6%, con lo cual se estableció el diagnóstico de metahemoglobinemia. El tratamiento administrado fueron dos dosis de azul de metileno, pero no hubo respuesta clínica. Por este motivo, se realizó electroforesis de hemoglobina, la cual fue compatible con hemoglobina M (Iwate o Kankakee), lo que se confirma su causa congénita de metahemoglobinemia.

Abstract Hemoglobin M is a rare hereditary disorder that causes ethemoglobinemia and therefore cyanosis. The clinical manifestations of this condition differs considerably, so it should be considered as a differential diagnosis in a newborn with cyanosis, with no other apparent cause. The case of a 5 hours old newborn is presented below, with generalized cyanosis from birth with oxygen saturations between 60-70%, in whom, upon ruling out pathologies such as perinatal hypoxia, pulmonary disease, heart disease and sepsis, a high level of methemoglobin is documented, reported in 21,6%; the diagnosis of methemoglobinemia was established. The treatment administered was two doses of methylene blue with no response. For this reason, hemoglobin electrophoresis was performed, which was compatible with Hemoglobin M (Iwate or Kankakee), confirming its congenital cause.

Progress in neonatal methemoglobinemia / 国际儿科学杂志

Neonatal methemoglobinemia is a rare disorder characterized by cyanosis and hypoxemia, which could be caused congenitally by cytochrome b5 reductase enzyme deficiency or hemoglobin M disease, and could be acquired by the exposure to lidocaine, nitrites and other drugs.Blood gas analysis is a simple and accessible way to detect methomoglobin.Methemoglobinemia is related to numerous diseases in neonates, including diarrhea, acidosis, late-onset sepsis.Methylene blue is an effective drug for decreasing MetHb levels.Other therapeutic options, such as vitamin C, N-acetylcysteine and vitamin B2, could also be useful.This article reviews the progress of neonatal methemoglobinemia.

Anesthetic Implication of Hemoglobin-M: A case report / 대한마취과학회지

Cyanosis in children is most often caused by pulmonary disease, or cyanotic heart disease but is rarely caused by hematological problems such as methemoglobinemia and sulfhemoglobinemia. Abnormal hemoglobins with a reduced oxygen affinity are an exceptionally uncommon cause of cyanosis in children. Hemoglobin-M (Hb-M) is rapidly auto-oxidized into the met-form resulting in the loss of its O2-binding ability. This hemoglobinopathy is inherited in an autosomal dominant pattern and is characterized by marked cyanosis. Hb-M affects the anesthetic management because of the anomalous absorption spectrum of Hb-M in standard pulse oximetry. Sufficient O2 delivery should be maintained by keeping a high FiO2 and intermittently checking the O2 delivery state using arterial blood gas analysis. We reported our experience of the anesthetic management of a patient with hemoglobin M.