Acquired Methemoglobinemia in the Surgical Intensive Care Unit.

Acquired methemoglobinemia is a potentially lethal medical condition caused by exposure to oxidizing xenobiotics, including antibiotics such as dapsone and inhaled anesthetics such as benzocaine. In this case report, we describe two presentations of acquired methemoglobinemia which presented to our surgical intensive care unit within one month. This highlights the potential connection between an emergent surgery or procedure and the development of methemoglobinemia in an environment where it is presumed that this condition would be extremely rare. High clinical suspicion for methemoglobinemia is warranted if the patient develops cyanosis or a decreased oxygen saturation unresponsive to supplemental oxygen when another etiology is not identifiable. If methemoglobinemia is suspected, a direct measurement of blood methemoglobin levels can be obtained to confirm the diagnosis. Prompt treatment with intravenous methylene blue is highly effective.