Individuals with sickle cell disease have abnormal hemoglobin, called hemoglobin S, in their red blood cells, which causes the cells to be abnormally shaped and rigid. Exchange transfusion is performed to remove the abnormal sickle red blood cells and replace them with normal red blood cells, reducing the incidence of complications, including acute chest syndrome, stroke, and multi-organ failure.
An exchange transfusion lowers the percentage of hemoglobin S red blood cells in the body. When there are fewer sickled hemoglobin S cells in the bloodstream, there is less likelihood of buildup or blockage in blood vessels.
Exchange transfusion also increases the concentration of normal red blood cells in the body, which supplies more oxygen to the body.