Methaemoglobinaemia is a condition due to the presence in the blood of METHAEMOGLOBIN. It is characterised by CYANOSIS which turns the skin and lips a blue colour, shortness of breath, headache, fatigue and sickness. There are two main forms: a hereditary form and a toxic form. The latter is caused by certain drugs, including acetanilide, phenacetin, the sulphonamides and benzocaine. The treatment of the toxic form is the withdrawal of the causative drug. In the more severe cases the administration of methylene blue or ascorbic acid may also be needed, and these are the drugs used in the hereditary form.
A derivative of HAEMOGLOBIN in which the iron has been oxidised from ferrous to ferric form. It does not combine with oxygen and therefore plays no part in oxygen transport. Normal concentration of methaemoglobin in red blood cells is less than 1 per cent of the total haemoglobin. When a large concentration of the haemoglobin is in the form of methaemoglobin, the patient will suffer from HYPOXIA and will be cyanosed (see CYANOSIS). Most cases of METHAEMOGLOBINAEMIA are due to chemical agents.... methaemoglobin
A condition in which the skin – usually of the face and extremities – takes on a bluish tinge. It accompanies states in which the blood is not properly oxygenated in the lungs, and appears earliest through the nails, on the lips, on the tips of the ears, and over the cheeks. It may be due to blockage of the air passages, or to disease in the lungs, or to a feeble circulation, as in heart disease. (See CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD); METHAEMOGLOBINAEMIA.)... cyanosis
Methylene blue, or methylthionin chloride, is used in a dose of 75–100 mg, as a 1-per-cent intravenous injection, in the treatment of METHAEMOGLOBINAEMIA, which may occur following high doses of local anaesthetics such as prilocaine.... methylene blue
The toxic effects of chemicals present in some defoliant weedkillers. Ingesting chlorates can cause kidney and liver damage, corrosion of the intestine, and methaemoglobinaemia (a chemical change in haemoglobin in the blood). Small doses of chlorates can prove fatal. Symptoms of poisoning include ulceration in the mouth, abdominal pain, and diarrhoea.... chlorate poisoning
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