Methemoglobinemia Case Study
A 26-week old baby was brought to the pediatric clinic because of increasing lethargy and cyanosis. The infant had been in good health at birth, and the mother had attempted breastfeeding. Because the motherâs milk flow had virtually ceased, the family physician recommended formula feeding. A blood sample was collected and a positive test for methemoglobinemia was obtained. The baby then was treated with intravenous ascorbate and methylene blue. Within 2 days the child was alert, and the cyanosis had disappeared. The child was discharged with instructions to the mother concerning formula preparation with distilled water.
BIOCHEMICAL QUESTIONS:
Define specialized terms.
Note the significance of quantities given and compare to normal values.
What is the chemical difference between hemoglobin and methemoglobin, and how do their oxygen-carrying capacities compare?
What mechanisms normally prevent accumulation of methemoglobin in the blood?
What is the cause of the cyanosis associated with toxic methemoglobinemia?
How does toxic methemoglobinemia compare with congenital methemoglobinemia?
What is the biochemical basis for treatment of toxic methemoglobinemia with intravenous ascorbate and methylene blue?
Methemoglobinemia Case Study
A 26-week old baby was brought to the pediatric clinic because of increasing lethargy and cyanosis. The infant had been in good health at birth, and the mother had attempted breastfeeding. Because the motherâs milk flow had virtually ceased, the family physician recommended formula feeding. A blood sample was collected and a positive test for methemoglobinemia was obtained. The baby then was treated with intravenous ascorbate and methylene blue. Within 2 days the child was alert, and the cyanosis had disappeared. The child was discharged with instructions to the mother concerning formula preparation with distilled water.
BIOCHEMICAL QUESTIONS:
Define specialized terms.
Note the significance of quantities given and compare to normal values.
What is the chemical difference between hemoglobin and methemoglobin, and how do their oxygen-carrying capacities compare?
What mechanisms normally prevent accumulation of methemoglobin in the blood?
What is the cause of the cyanosis associated with toxic methemoglobinemia?
How does toxic methemoglobinemia compare with congenital methemoglobinemia?
What is the biochemical basis for treatment of toxic methemoglobinemia with intravenous ascorbate and methylene blue?
