Pro: Exchange transfusion is required for sickle cell trait patients undergoing cardiopulmonary bypass

Abstract

SICKLE CELL HEMOGLOBINOPATHY is a common recessive gene abnormality characterized by a single base mutation of adenine to thymine that results in a substitution of valine for glutamine at position 6 of the beta-hemoglobin chain. Sickle hemoglobin has altered solubility characteristics that result in polymerization as it becomes deoxygenated, giving affected cells their characteristic shape. When hemoglobin S (HbS) is present in high concentrations within a red cell it undergoes repeated cycles of sickling and desickling which result in progressive damage, with the affected erythrocytes eventually becoming irreversibly deformed. Sickled red cells have a reduced life span and an increased tendency to adhere to vascular endothelium, hence the clinical symptoms and signs of chronic hemolytic anemia and organ damage caused by small-vessel occlusion found in the homozygous disease state.