title: Incidence and pathogenesis of acute megaloblastic bone-marrow change in patients receiving intensive care.
abstract: The incidence and pathogenesis of acute megaloblastic bone-marrow change and of abnormalities in DNA synthesis, as assessed with the deoxyuridine(dU) suppression test, have been investigated in a prospective study of 70 seriously ill patients admitted to an intensive-care unit. On admission megaloblastic bone-marrow change was present in 22 patients, 18 of whom had been anaesthetised with nitrous oxide for 2-6 h during surgical procedures before admission. 16 of these 18 patients died, compared with 7 of 22 patients in whom haemopoiesis remained normoblastic despite receiving equivalent amounts of nitrous oxide. An abnormal dU-suppression test developed only in patients who had received nitrous oxide; on admission an abnormal dU-suppression test was found in 39 of the 42 patients tested who had been exposed to the anaesthetic. The abnormality produced in the dU-suppression test by nitrous oxide in patients admitted to the intensive-care unit was more severe and recovery was slower than the abnormality seen in patients undergoing cardiac-bypass surgery. During the recovery period from the effects of nitrous oxide the pattern of correction of the dU-suppression test changed from that of vitamin-B12 deficiency to folate deficiency.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000748:Anemia, Macrocytic / Q000139:chemically induced*; D000749:Anemia, Megaloblastic / Q000139:chemically induced* / Q000175:diagnosis; D000758:Anesthesia / Q000009:adverse effects; D001853:Bone Marrow / Q000187:drug effects*; D002648:Child; D004247:DNA / Q000378:metabolism; D003857:Deoxyuridine; D005260:Female; D005492:Folic Acid / Q000378:metabolism; D005494:Folic Acid Deficiency / Q000139:chemically induced; D006410:Hematopoiesis / Q000187:drug effects; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009609:Nitrous Oxide / Q000009:adverse effects*; D014805:Vitamin B 12 / Q000378:metabolism
chemical_list: D004247:DNA; D005492:Folic Acid; D009609:Nitrous Oxide; D014805:Vitamin B 12; D003857:Deoxyuridine