Methemoglobinemia is a medical condition brought about by high levels of methemoglobin in the blood. Methemoglobin is a form oxygen-carrying metalloprotein in the blood. Unlike oxyhemoglobin that is also found in the blood, methemoglobin does not release oxygen it contains. For this reason, it takes bluish chocolate-brown color. In a normal situation, between one and two percent of human blood is methemoglobin. An increase in the percentage causes a pulse Oximeter reading close to 85%, regardless of the actual concentration of oxygen in the blood.
Causes of Methemoglobinemia Syndrome
High level of methemoglobin is usually due to deficiency of enzyme diaphorase I (NADH methemoglobin reductase). Increased levels of methemoglobin means reduced levels of oxygen in the blood. This leads to blood not exhibiting its natural reddish color but instead turns bluish or brownish. This can clearly be seen in Caucasian patients who normally exhibit bluish color on their skin.
Although the main cause of Methemoglobinemia is increased levels of metheglobin in the blood, there are various factors that facilitate the raise. Genes play a crucial role in the occurrence of the condition due to the fact that it can be inherited. Having abnormal blood variants such as hemoglobin M and H, which are not amenable to reduction even with intact enzyme system increases the risk of having Methemoglobinemia. The condition can also be facilitated deficiency of pyruvate kinase, which causes impaired production of NADH. Several medications are also associated with the occurrence of Methemoglobinemia. Such include antibiotics, anesthetics, nitrates and aniline dyes.
How a Baby Contracts Methemoglobinemia Syndrome?
Babies under the age of 6 months are highly susceptible to Methemoglobinemia, which they contract through acquisition or inheritance (congenital). A baby will contract congenital Methemoglobinemia from either parent through genes with altered form of hemoglobin (M or H) and NADH reductase deficiency. Such decrease the rate of reduction of iron in blood molecule. A baby can also acquire Methemoglobinemia after birth. This is usually due to exposure to oxidant medications and toxins. Acquired Methemoglobinemia is more frequent that congenital Methemoglobinemia. This is attributed to several factors including the fact that the level of NADH reductase is usually low at birth and only increases as a baby grows.
Symptoms of Methemoglobinemia Syndrome
Methemoglobinemia presents varied symptoms in babies, some of which cannot be detected physically. Symptoms include
- Restlessness due to shortness of Breath
- Cyanosis (on the nose, cheeks, fingers and toes)
- General body weakness
- Loss of consciousness
- Bluish skin color
- In extreme cases, coma and death
Treatment of Methemoglobinemia Syndrome
Babies with Methemoglobinemia are usually at high risk of death in case medical attention is not sought. The first line of treatment is usually through oxygen supplementation, which can be administered alongside methlene blue solution, which is administered intravenously over some time. Methlene blue has the effect of restoring iron in blood to normal levels. The presence of methlene blue in the blood allows NADH reductase to function at an increase rate. Other helpful treatment methods include administration of vitamin C, which has the effect of reducing cyanosis. Vitamin C in particular is very effective in treating acquired Methemoglobinemia.