[Acute megaloblastic anemia caused by inhalation of nitrous oxide in a patient with multiple autoimmune pathology].
Although megaloblastic anemias are generally regarded as chronic conditions of insidious appearance, a megaloblastic state can arise over the course of only a few days due to acute folate or vitamin B12 deficiency. One of the most common causes, though seldom reported, is the nitrous oxide (N02) action in tissue. In fact N02, a volatile substance commonly used in anaesthesia, destroys methylcobalamin, leading to the rapid development of a megaloblastic haematopoiesis. This phenomenon may occur in patients without previous vitamin B12 deficit, but is more frequent and severe when there is a pre-existent deficiency state. A case report is described of a patient with femoral fracture who developed acute anemia after surgery and a latent pernicious anemia was revealed upon investigation.
Serviço de Medicina, Hospital de S. José, Lisboa.
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D000208:Acute Disease; D000368:Aged; D000749:Anemia, Megaloblastic / Q000139:chemically induced*; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D005260:Female; D005265:Femoral Neck Fractures / Q000601:surgery; D006801:Humans; D009609:Nitrous Oxide / Q000009:adverse effects*
D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide