Hi I was wondering does methemoglobinemia effect the limb where the injection of anaesthetic has taken place or does it effect the whole body

Hi there

Thanks for the question!

It impacts the whole body! Methemoglobinemia (congenital or acquired) occurs when red blood cells (RBCs) contain methemoglobin at levels higher than 1%. Methemoglobin results from the presence of iron in the ferric form instead of the usual ferrous form. This results in a decreased availability of oxygen to the tissues. Symptoms are proportional to the methemoglobin level and include skin color changes and blood color changes at levels up to 15% (see the image below). As levels rise above 15%, neurologic and cardiac symptoms arise as a consequence of hypoxia. Levels higher than 70% are usually fatal.

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Mike MacKinnon MSN FNP-C CRNA


I am a former Trauma Flight RN now a Family Nurse Practitioner and a Nurse Anesthetist (CRNAs). I can help answer questions on the CRNA profession and clinical anesthesia. I work full time as an independent practice CRNA and have a special interest in regional anesthesia, particularly peripheral nerve blocks. I also teach ultrasound regional anesthesia and lecture all over the country. If I do not know the answer, I will find it for you.


I am a Family Nurse Practitioner and a Nurse Anesthetist who works as an independent/autonomous practitioner. There are often questions about my profession and I would like to offer the service of an actual CRNA. If you did not know, there are about 40000 of us which equates to 50% of the anesthesia providers in the USA today. I also lecture and teach ultrasound regional anesthesia all over the country.

AANA (American Association of Nurse Anesthetists)
IARS (International Anesthesia Research Society) AANP (American Association of Nurse Practitioners)

Air Medical Transport Journal
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Bachelors of Science in Nursing
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