Transfusion support for patients with sickle cell disease.

Red blood cell (RBC) transfusion is an essential treatment for many patients with sickle cell disease (SCD), whose RBCs express hemoglobin S (HbS), a mutated form of hemoglobin A (HbA). Transfusion goals include increasing blood oxygen carrying capacity and decreasing the relative amount of HbS to HbA to mitigate vaso-occlusion in small blood vessels. In situations where correction of severe anemia and reduction in HbS may be achieved without removal of RBCs, simple transfusion may be utilized. Partial manual RBC exchange, which removes blood containing HbS by phlebotomy and replaces with donor blood transfusion sequentially allows for larger changes in the ratio of HbS to HbA when compared to simple transfusion. Automated RBC exchange by apheresis is useful in situations where a rapid and drastic HbS reduction is indicated. Vascular access is an important consideration for transfusion. Although peripheral access may be sufficient, central venous catheters and implantable venous access devices may be necessary for adequate access over time. Blood bank considerations include adequate RBC antigen matching to mitigate the risk of RBC alloimmunization, of which patients with SCD are at risk of developing. Transfusion may be utilized in efforts to intervene in the evolution of potentially life-threatening complications of SCD such as acute stroke, severe acute anemia and acute chest syndrome. Transfusion is also useful in several non-acute settings, such as stroke prevention, pregnancy, pre-surgery, and transfusion support for curative therapies. Individualized treatment plans are an essential component of patient care. Continuous evaluation of clinical indications and evolution of guidelines will continue to optimize care for patients with SCD.