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The inherited hemoglobin disorders stem from abnormal Hb structure (eg, sickle cell disease [SCD] or abnormal Hb production (eg, the thalassemias). Anemia occurs when destruction of red blood cells outstrips production. Most patients are aware of their dyshemoglobinemia status.
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The most common complaints in SCD (homozygous (HbSS) or sickle trait (heterozygus [HbAS]) patients are pain, localized or generalized, weakness, or infectious complaints. Physical examination findings commonly include pale complexion, venous stasis changes, jaundice, hepatosplenomegaly, anemic cardiac flow murmurs, cardiomegaly, and high output CHF.
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Painful vaso-oclusive crisis in the musculoskeletal system or diffusely in the abdomen are the most common presentation to the ED. Crisis occur when sickled RBCs mechanically obstruct blood flow, causing ischemia, organ damage, and infarcts. Crisis-causing stresses include fever or infection (especially encapsulated organisms Haemophilus influenza or Pneumococcus), cold exposure or high altitude, dehydration or overexertion, medication noncompliance, or drug use.
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Acute symptomatic anemia results from splenic sequestration or bone marrow failure (aplastic crisis) and presents with weakness, dyspnea, CHF, or shock.
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Life or limb-threatening events seen in SCD patients include acute chest syndrome (vaso-occlusive pulmonary insult), stroke, renal infarct, mesenteric infarcts, sepsis, osteomyelitis, pneumonia, or priapism.
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Diagnosis and Differential
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The degree of illness guides the evaluation of an acute crisis. Although workups should be individualized, the more common protean complaints (pain, weakness, fever) must include a search for a cryptic inciting event. See Table 136-1.
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