Abstract
Background
Methemoglobinemia can be a potentially lethal condition due to the hypoxic stress
placed on the body. In pregnancy, the deleterious effects can be even more catastrophic.
The benefits of treatment in all patients, especially in those who are pregnant, must
outweigh the inherent risks of the therapies used to treat methemoglobinemia.
Case Report
We present a case of a 26-year-old Hispanic pregnant female at 30 weeks gestation
presenting to the emergency department for chest pain, hypoxia, and cyanosis. She
was subsequently diagnosed with methemoglobinemia, treated with methylene blue, and
admitted to the intensive care unit with toxicology and obstetrics consultations.
As an outpatient, the patient underwent genetic testing and was diagnosed with homozygous
cytochrome b5 reductase deficiency as the etiology of the methemoglobinemia.
Why Should an Emergency Physician Be Aware of This?
Methemoglobinemia is a rare, potentially lethal, but treatable condition. In the setting
of pregnancy, methemoglobinemia can pose a significant risk to the mother and fetus
by causing acute hypoxia. Because methemoglobinemia can be acquired or congenital,
treatments vary based on the etiology. Methylene blue is the mainstay treatment for
symptomatic methemoglobinemia of levels > 20%. The teratogenic risks of methylene
blue require risk−benefit analysis and discussion with the patient before utilization.
Systemic maternal administration is theorized to be of lowest risk to the fetus. In
this case, methylene blue was used safely as an emergent therapy for congenital methemoglobinemia
during pregnancy.
Keywords
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Article info
Publication history
Published online: April 04, 2018
Accepted:
January 25,
2018
Received in revised form:
December 21,
2017
Received:
September 21,
2017
Identification
Copyright
© 2018 Elsevier Inc. All rights reserved.
