What is the pathophysiology of acquired methemoglobinemia?

Updated: Dec 09, 2018
  • Author: Mary Denshaw-Burke, MD, FACP; Chief Editor: Emmanuel C Besa, MD  more...
  • Print
Answer

Acquired methemoglobinemia is much more common than the congenital form and involves excessive production of methemoglobin. The incidence may be much higher than is documented. Often, this is associated with the use of or exposure to oxidant drugs, chemicals, or toxins, including dapsone, [12] local anesthetic agents, [13] and nitroglycerin. This increased production overwhelms the normal physiologic regulatory and excretory mechanisms. These oxidant agents can cause an increase in methemoglobin levels either by ingestion or by absorption through the skin. A study involving two tertiary care teaching hospitals, indicated that methemoglobinemia was present in a significant proportion of all hospitalized patients, and the frequency may be much more than anticipated or expected. [14]

The presence of methemoglobin may also be a marker and predictor of sepsis, resulting from release of excessive amounts of nitrous oxide (NO). [15]


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!