American family physician
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Vitamin B12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders. The role of B12 deficiency in hyperhomocysteinemia and the promotion of atherosclerosis is only now being explored. Diagnosis of vitamin B12 deficiency is typically based on measurement of serum vitamin B12 levels; however, about 50 percent of patients with subclinical disease have normal B12 levels. ⋯ Use of the Schilling test for detection of pernicious anemia has been supplanted for the most part by serologic testing for parietal cell and intrinsic factor antibodies. Contrary to prevailing medical practice, studies show that supplementation with oral vitamin B12 is a safe and effective treatment for the B12 deficiency state. Even when intrinsic factor is not present to aid in the absorption of vitamin B12 (pernicious anemia) or in other diseases that affect the usual absorption sites in the terminal ileum, oral therapy remains effective.
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Delirium is characterized by an acute change in cognition and a disturbance of consciousness, usually resulting from an underlying medical condition or from medication or drug withdrawal. Delirium affects 10 to 30 percent of hospitalized patients with medical illness; more than 50 percent of persons in certain high-risk populations are affected. The associated morbidity and mortality make diagnosis of this condition extremely important. ⋯ Low doses of antipsychotic drugs can help to control agitation. The use of benzodiazepines should be avoided except in cases of alcohol or sedative-hypnotic withdrawal. Environmental interventions, including frequent reorientation of patients by nursing staff and education of patients and families, should be employed in all cases.