Methemoglobinemia 

Methemoglobinemia  When excessive hemoglobin in the blood is converted to another chemical that cannot deliver oxygen to tissues, called methemoglobin.

What is Methhemoglobin? The molecule hemoglobin in the blood is responsible for binding oxygen to give to the body. When hemoglobin is oxidized to methemoglobin its structure changes and it is no longer able to bind oxygen

How much is normal . Hemoglobin is constantly under oxidizing stresses: however, normally less than 1% of a person's hemoglobin is in the methemoglobin state.

Why? due to the body's systems that reduce methemoglobin back to hemoglobin. Infants have a higher risk of acquiring methemoglobinemia because infant hemoglobin is more prone to be oxidized to methemoglobin

How do I get it Methemoglobinemia can either be congenital or acquired

Congenital There are two causes of the congenital form. One cause is a defect in the body's systems to reduce methemoglobin to hemoglobin. The other cause is a mutant form of hemoglobin called hemoglobin M that cannot bind to oxygen. Both of these forms are typically benign.

Acquired Acquired methemoglobinemia is caused by an external source, usually a drug or medication. Some of these medications include benzocaine, lidocaine and prilocaine. These medications can inhibit the body's systems of reducing methemoglobin to hemoglobin resulting in methemoglobinemia

Signs 3 to 15% With a methemoglobin level of 3-15% skin can turn to a pale gray or blue (cyanosis).

Symptoms above 25% With levels above 25% the following symptoms may be present: Cyanosis unaffected by oxygen administration Blood that is dark or chocolate in color that will not change to red in the presence of oxygen Headache Weakness Confusion Chest pain

When methemoglobin levels are above 70% death may result if not treated immediately

Diagnosis is based on the symptoms and history Diagnosis is based on the symptoms and history. If these are indicative of methemoglobinemia blood tests are performed to confirm the presence and level of methemoglobin.

Field monitoring of methhemoglobin The new LP15 will do non-invasive monitoring for methhemoglobin. The monitoring is done by finger probe using rainbow technology.

Treatment For acquired methemoglobinemia the typical treatment is with methylene blue. This is administered with an IV over a five-minute period and results are typically seen within 20 minutes. Methylene blue reduces methemoglobin back to hemoglobin.

Treatment Though congenital methemoglobinemia is usually benign, the form due to a defective reducing system can be treated with ascorbic acid (vitamin C) taken daily. The other congenital form due to hemoglobin M has no treatment as of late.

Prognosis If found early, acquired methemoglobinemia can be easily treated with no side effects. After treatment with methylene blue the patient can expect a full recovery. Congenital methemoglobinemia is typically benign and should be observed