Sickle Cell Disease and Red Cell Exchange
     • Sickle cell disease is a major health problem with significant 
       morbidity and mortality.
     • In many patient’s supportive management is sufficient, 
       however some patient’s need more aggressive therapy 
       such as red cell exchange.
     • The majority of transfusions for sickle cell disease are 
       simple red cell transfusions. These transfusions add oxygen 
       carrying capacity.
     • Unless there is bleeding or rapid cell destruction, the 
       hemoglobin concentration and viscosity of the blood is 
       increased. 
    Swerdlow P S Hematology 2006;2006:48-53
     Sickle Cell Disease and Red Cell Exchange
    • The viscosity of blood is a key concept in the 
      management of transfusions in sickle cell 
      disease. 
    • The blood viscosity increases with increasing 
      hemoglobin levels and limits blood flow and 
      oxygen transport.
    • Deoxygenated sickle cells have nearly a 10-fold 
      greater viscosity than oxygenated sickle cells at 
      the same hemoglobin level. 
    Swerdlow P S Hematology 2006;2006:48-53
     Sickle Cell Disease and 
     Red Cell Exchange
     •  Transfusing normal 
        red blood cells to 
        individuals with 
        sickle cell disease 
        increase the 
        viscosity.
     •  The following 
        diagram shows 
        oxygen transport 
        vs. hemoglobin 
        levels. 
  Swerdlow P S Hematology 2006;2006:48-53
      Sickle Cell Disease and Red Cell Exchange
    • Red cell exchanges can administer blood without 
       a corresponding increase in viscosity.
    • Red cell exchanges are used to not only increase 
       oxygen carrying capacity but to also decrease 
       complications of sickle cell disease. 
    • This procedure is indicated in primary and 
       secondary vaso-occlusive stroke prevention, acute 
       chest syndrome, multiorgan failure syndrome, and 
       chronic maintenance of low Hgb S levels.
  Swerdlow P S Hematology 2006;2006:48-53
      Sickle Cell Disease and Red Cell Exchange
     • Red cell exchange has been used in patients who are to 
       undergo major surgeries to decrease incidence of 
       postsurgical complications and individuals without sickle cell 
       disease who have parasitemia of the blood due to malaria. 
     • Other indications for red cell exchange with less supporting 
       evidence are elements of the triad of pulmonary 
       hypertension, priapism, and leg ulcers associated with red 
       cell hemolysis, chronic hypoxia not controllable with oxygen 
       therapy, repeated episodes of acute chest syndrome or 
       multiorgan failure syndrome, or multiple severe pain 
       episodes interfering with major life goals. 
   Swerdlow P S Hematology 2006;2006:48-53