1. A clinical condition in which more than 1% of the haemoglobin in the blood has been oxidized to the ferric (Fe3+) state. The principle finding is cyanosis due to the oxidized haemoglobins inability to transport oxygen. Nitrites can cause this condition and it has been reported in commercial meat packers. Treatment may include ascorbic acid or methylene blue.
It may be drug-induced or be due to a defect in the enzyme NADH methaemoglobin reductase (an autosomal recessive trait) or to an abnormality in haemoglobin M (an autosomal dominant trait).
Origin: Gr. Haima = blood
(29 Sep 1997)
