TREATMENT OF METHEMOGLOBINEMIA

1. The minimal lethal level of p-aminopropiophenone induced methemoglobinemia in dogs is about 80 to 85 per cent of the total blood pigment. 2. At very high but non-lethal levels, methemoglobinemia is reduced much more rapidly by methylene blue than by ascorbic acid or by BAL. At an intravenous dose of 1 mgm. per kgm. methylene blue is highly and rapidly effective in saving dogs from death at degrees of methemoglobinemia which would otherwise be fatal. 3. A correlation of the clinical literature with the experimental results obtained in the present study, indicates that the minimal lethal level of methemoglobinemia in man approaches that in the dog and that an intravenous dose of 1 to 2 mgm. methylene blue per kgm. is highly and rapidly effective in counteracting the symptoms of severe methemoglobinemia.