'Blue blood' found in a woman's blood drawn to the emergency room

Blue blood was drawn from an American woman's body. It was because of the side effects of benzocaine. 

Forbes reported on the 19th (local time) by quoting a report in the New England of Madison, a medical journal published by the Massachusetts Medical Association. 

Recently, an American woman took benzocaine because of toothache. Later, dyspnea and cyanosis appeared, so I went to the hospital. 

A blue blood sample was drawn to her during a blood sample at the hospital. Warren, the doctor in charge, was surprised to say, "I have studied theoretically, but in practice it is very rare." 

High doses of benzocaine increase the concentration of methemoglobin in the blood. As a side effect, methemoglobinemia occurs. Sometimes the skin is blue. When the level of methemoglobin in the blood reaches 70% or more, death occurs. 

However, it is not uncommon for the blood to be blue as well as the skin. Generally, cyanosis appears when the concentration of methemoglobin exceeds 10%. The concentration of this woman was 44%. The oxygen saturation was also 30% lower than the normal range. Because of the high level, the blood became blue. 

This woman was prescribed twice intravenous methylene blue and followed her course. After a day, the condition returned to normal and she was discharged. 

<Photo source = New England Journal of Madison>