Red Blood Cell Exchange
What is Sickle Cell Disease?
Sickle Cell Disease is a group of inherited red blood cell disorders. Normal red blood cells are round like doughnuts and they move through small blood tubes in the body to deliver oxygen. Sickle red blood cells become hard, sticky and shaped like sickles used to cut wheat. When these hard and pointed red cells go through the small blood tube, they clog the flow and break apart. This can cause pain, damage and a low blood count, or anemia.
What is the treatment for Sickle Cell Crisis?
Sickle cell anemia has no widely available cure. However, treatments can help relieve symptoms and treat complications. The goals of treating sickle cell anemia are to relieve pain, prevent infections, organ damage and strokes and to control complications. Red Cell Exchange transfusions are used in high-risk sickle cell patients to remove sickled red blood cells. It's typically done on a monthly basis to prevent further complications of sickle cell disease, but it may also be done in an emergency for patients in crisis. This procedure minimizes the development of iron overload.
What causes the red blood cell to sickle?
There is a substance in the red cell called hemoglobin that carries oxygen inside the cell. One little change in this substance causes the hemoglobin to form long rods in the red cell when it gives away oxygen. These rigid rods change the red cell into a sickle shape instead of the round shape.
Why do people become iron overloaded from chronic transfusions with packed red blood cells?
Iron is good for you--in the right amount. Iron helps your body to work properly but too much iron can be harmful. If you have had 10 or more blood transfusions, you may have too much iron in your body. That's because every time you have a transfusion, you get healthy red blood cells that your body needs. But you also get extra iron that your body doesn't need. Iron cannot be removed from the blood before the transfusion. Iron helps red blood cells do their job. Without iron, the healthy red blood cells that you get during your transfusion won't be able to carry oxygen. But your body doesn't have a natural way to get rid of this iron. Over time the iron builds up in your body causing a condition called iron overload.
How do you get Sickle Cell Disease?
You inherit the abnormal hemoglobin from your parents, who may be carriers with sickle cell trait or parents with sickle cell disease. You cannot catch it. You are born with the sickle cell hemoglobin and it is present for life. If you inherit only one sickle gene, you have sickle cell trait. If you inherit two sickle cell genes you have sickle cell disease.
What problems are caused by iron overload?
Most people will not feel the iron slowly building up in their body, damaging their organs. That is because for most people, iron overload has no symptoms. As iron builds up in the body, it can lead to serious health problems, such as heart, kidney or liver disease, endocrine system dysfunction, bone pain, joint pain/deterioration and significant skin discoloration.
What are the complications of Sickle Cell Disease?
Complications from the sickle cells blocking blood flow and early breaking apart include:
- Pain episodes
- Increased infections
- Leg ulcers
- Bone damage
- Yellow eyes or jaundice
- Yearly gallstones
- Lung blockage
- Kidney damage
- Painful erections in men (priapism)
- Blood blockage in the spleen or liver (sequestration)
- Eye damage
- Low red blood cell counts (anemia)
- Delayed growth
How is a Red Cell Exchange procedure done?
During the exchange procedure blood is withdrawn from the patient by placing a venous access device (catheter, port) into the patient's vein. The device is connected to a machine, which contains a centrifuge that draws the blood from the patient and then separates it into red blood cells, white blood cells, platelets and plasma, the liquid portion of blood. The healthy components of the blood are returned to the patient, while the unhealthy components are discarded. A calculated number of units of healthy red blood cells are infused while the diseased (sickled) red blood cells are removed.
A special red blood cell exchange program at Hoxworth Blood Center has vastly improved the quality of life of sickle cell disease patients. The program for both children and adults has reduced complications of the disease. Typically exchanges are performed monthly to maintain a "safe" level of abnormal (sickled) cells and a adequate number of red cells to prevent anemia.
What are the types of venous access devices used to do this procedure?
Apheresis ports are placed in the upper area of the chest bilaterally. They are under the skin and patients can swim, shower, etc. with the ports. A dialysis catheter can be placed in several different locations and can be used for a temporary access or can be tunneled and provide for access long term. The red and blue tipped tubes containing clamps are above the skin limiting the ability for showers, swimming etc. Occasional peripheral intravenous access can be achieved to do this procedure but over time alternative access will be needed.