TY - CHAP M1 - Book, Section TI - Sickle Cell Disease in Children A1 - Marshall, John P. A2 - Tintinalli, Judith E. A2 - Ma, O. John A2 - Yealy, Donald M. A2 - Meckler, Garth D. A2 - Stapczynski, J. Stephan A2 - Cline, David M. A2 - Thomas, Stephen H. PY - 2020 T2 - Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 9e AB - Sickle cell disease is a spectrum of blood disorders of which sickle cell anemia (SCA) is the most serious. SCA is found primarily in children of African, Arab, or Mediterranean descent. It is caused by a single amino acid substitution in the sixth position of the β-globulin chain of normal adult hemoglobin (HbA), which creates the abnormal sickle hemoglobin (HbS). The HbS chain found in patients with SCA creates a hydrophobic region of the hemoglobin tetramer when it is deoxygenated.1 In this state, noncovalent polymerization of the hemoglobin molecules creates chains that distort the shape of the membrane, causing the characteristic sickle appearance. The altered red blood cell shape and its associated rigidity and decreased deformability cause sickle cells to impede blood flow. This process is primarily responsible for the clinical manifestations of SCA through two mechanisms: hemolytic anemia and vaso-occlusion with subsequent ischemia-reperfusion injury. Interruption of blood flow created by the abnormal cells leads to poor tissue perfusion, acidosis, and hypoxia, which cause further sickling. The need to reverse these conditions is central to the management of SCA-related complications. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessemergencymedicine.mhmedical.com/content.aspx?aid=1166596080 ER -