Methemoglobinemia


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Related to Methemoglobinemia: Blue baby syndrome

methemoglobinemia

[¦met‚hē·mə·glō·bə′nē·mē·ə]
(medicine)
The presence of methemoglobin in the blood.

Methemoglobinemia

 

the appearance of methemoglobin in the blood as a result of the toxic effect of various chemical substances (nitrates and nitrites, aniline, pyridine) that are capable of converting hemoglobin to methemoglobin (MtHb) upon entering the body through the skin, digestive tract, or lungs. With considerable methemoglobinemia, oxygen starvation, or hypoxia, may result. Methemoglobin may be excreted with the urine (methemoglobinuria); this is sometimes damaging to the kidneys. Methemoglobinemia is treated with antidotes (methylene blue, ascorbic acid) and oxygen therapy.

References in periodicals archive ?
The signs and symptoms of methemoglobinemia vary depending on the fraction of methemoglobin.
In this regard, infants' illness and death from nitrite induced methemoglobinemia have been reported by [22].
When high levels of nitrite accumulate, they are absorbed into the bloodstream where they change hemoglobin to methemoglobin, a condition known as methemoglobinemia. Methemoglobin cannot carry oxygen like hemoglobin (Patel et al., 2013), thus resulting in ill health or even death of the animal in severe cases.
It is difficult not to notice methemoglobinemia, as the baby's skin turns blue.
That issue came to the fore when medical doctors began to treat cases of infant methemoglobinemia in farming areas (Walton 1951).
Methemoglobinemia, hoarseness of voice, cardiac toxicity, hepatitis, hypotension, convulsions, coma, and sudden cardiac death are on the toxic end of the spectrum.
Toxic metabolites cause methemoglobinemia and hepatotoxicity (McConkey et al., 2009); Bedlington Terriers are known for their tendency to accumulate copper in the hepatocytes (Coronado et al., 2008) while several dog breeds such as Collies, Australian Shepherd Dog or Shetland Sheepdog are sensitive to ivermectine and other avermectins that cross into the central nervous system provoking neurotoxicity (Volmer and Meerdink, 2002).
Congenital or inherited causes of methemoglobinemia result due to decreased activity of the enzyme cytochrome b5 reductase resulting in diminished enzymatic reduction of the hemoglobin molecule.
Hegedus and Herb (2005) described that benzocaine at high concentrations may lead to methemoglobinemia, preventing iron in the hemoglobin to transport oxygen to the tissues.
In most cases exposure to high level of nitrates due to excessive use of nitrogenous fertilizers may result methemoglobinemia in children.
Methemoglobinemia is a complication of local anesthetic agents which may be fatal.