Methemoglobinemia: Infants at risk.

Methemoglobin is formed when the iron center in hemoglobin is oxidized from ferrous iron to ferric iron. The functional consequence of this change is that hemoglobin is transformed to methemoglobin and cannot oxygenate tissues adequately, causing hypoxia and cyanosis. Infants have unique physiology that increases their risk of developing methemoglobinemia.