Automated Red Blood Cell Exchange (Erythrocytapheresis)

What is automated red blood cell exchange?

Automated red blood cell exchange, also known as erythrocytapheresis, is a nonsurgical treatment to remove some of your child’s red blood cells — which may be harming your child — and replace them with red blood cells from a donor.

Red blood cells are responsible for carrying oxygen to all parts of your child’s body. When they are a different shape or size, or function improperly, they can affect your child’s overall health.

If your child has sickle cell disease or another rare disorder where her red blood cells are abnormal, your child’s doctor may recommend automated red blood cell exchange — rather than blood transfusions — as part of her long-term care management.

Regular blood transfusions can lead to an overload of iron in your child’s blood, which can be toxic and potentially fatal. Automated red blood cell exchange helps avoid this side effect of frequent transfusions.

Automated red blood cell exchange is not a cure, but it can help your child avoid complications from her disorder and improve her quality of life.

Who needs automated red blood cell exchange?

Automated red blood cell exchange can be performed on toddlers, children and adults. While children as young as 2 years old can receive an emergency red cell exchange, typically repeated and regular red cell exchanges don’t begin until after age 5.

Red blood cell exchange is used to treat:

  • Sickle cell disease and complications from the disorder, such as stroke, chest pain and a toxic overload of iron in the blood
  • ABO-incompatible bone marrow transplants
  • Some infections, such as malaria, where red blood cells are damaged

At The Children’s Hospital of Philadelphia, our pediatric Apheresis Program performs more than 1,200 automated red blood cell exchange procedures a year. Most are performed to treat children with sickle cell disease. CHOP’s Sickle Cell Center oversees the care of these children, and works closely with doctors, nurses and child life staff in the Apheresis Unit.

How is automated red blood cell exchange performed?

If your child is referred to the Apheresis Program for automated red blood cell exchange, she will have an initial evaluation by a physician-nurse team in the Apheresis Unit. The apheresis team will already know about your child and her condition from your child’s treating physician.

On the day of your child’s procedure, our team will greet you and your child when you arrive. You will be directed to a patient area that includes:

  • A reclining chair or bed for your child
  • A high-tech apheresis machine that will be customized for your child’s size and procedure
  • Room for you to sit with your child
  • A television to distract and entertain her

Your child’s procedure will be overseen by board-certified physicians, and experienced nurses and child life staff. One or more team members will be with your child at all times to provide comfort, answer questions, and ensure the apheresis procedure goes smoothly.

For an automated red blood cell exchange, your child’s blood will be withdrawn by a needle or catheter. In most cases, clinicians insert a needle into both of your child’s arms to withdraw and return the blood. Some children do not have very good veins in their arms. In that case, an implanted port can be placed to draw your child’s blood into and out of the apheresis machine.

Another way to withdraw your child’s blood is by a small tube (catheter) inserted into the groin or chest area. To place the catheter, a physician will make a small cut to insert the catheter. The skin will be numb, so your child should not have any pain during catheter placement.

The blood that’s withdrawn from your child will be circulated through a cell separator apheresis machine. A centrifuge in the machine separates the red blood cells from the other parts of the blood (white blood cells, plasma and platelets). The separated red blood cells are collected and discarded.

The remaining blood components are mixed with healthy red blood cells from a blood donor and returned to your child. In addition, your child will receive a small amount of citrate, an anticoagulant that will prevent your child’s blood from clotting during the procedure.

An automated red blood cell exchange may take one to four hours to complete, depending on your child’s size and how much blood has to be exchanged. Blood is slowly removed and returned into your child at the same time, so your child is never missing more than a few ounces of blood at a time.

Automated red blood cell exchange will be repeated at regular intervals under the direction of your child’s physician and the apheresis team. For conditions such as sickle cell disease, this procedure will be performed repeatedly for years to help your child live a more normal life.


Automated red blood cell exchange is a safe procedure, but side effects can occur.

Your child may experience:

  • Symptoms similar to regular blood donation, such as nausea, vomiting, dizziness or fainting
  • Problems related to the anticoagulant, including chills, sour taste in the mouth, tingling around the lips, muscle cramping, irregular heartbeats, or prolonged bleeding.
  • Bruising, numbness, pain or infection at the site of the needle stick or catheter insertion
  • Low or fluctuating blood pressure

If your child experiences any of these symptoms, please tell your child’s medical team.