Plasma exchange

This page explains about plasma exchange and what to expect when your child comes to Great Ormond Street Hospital (GOSH) to have this procedure.

What is plasma?

Plasma is part of blood. It is the liquid that supports the circulation of red blood cells, white blood cells and platelets. Plasma is mainly water and contains dissolved minerals, proteins and antibodies. If blood is allowed to separate, the plasma will look yellow and the rest of the blood will look red.

What is plasma exchange?

Plasma exchange, or plasmapheresis, is a procedure that removes plasma from the blood and replaces it with new plasma fluid. Blood is removed from the patient (a small amount at a time) and separated, so that the plasma can be discarded. The red and white blood cells and the platelets are returned to the patient, along with the replacement fluid. An anti-coagulant is added to the blood to stop it clotting.

Throughout the procedure, the blood is pumped around your child’s system as usual by their heart. Only a small amount is out of the body at any one time.

Plasma exchange is always done in hospital, and a nurse who is trained in the procedure will stay with your child throughout.

Before the procedure begins, your child’s doctor will ask you to sign a form giving permission for your child to have a plasma exchange. You should be told about the potential risks as well as the possible benefits.

How can plasma exchange help my child?

Some diseases can cause harmful substances to circulate in the blood. Plasma exchange allows these harmful substances to be removed by replacing the plasma which contains them.

For example, some diseases confuse the body’s immune system and cause it to produce substances called autoantibodies, which attack healthy cells. Plasma exchange, in conjunction with drug therapy, may solve the problem by removing the autoantibodies and stopping the body from producing any more.

Your child’s doctor will discuss with you the reason why your child needs a plasma exchange and how it might help.

How will the procedure be carried out?

Two alternative methods are used to separate plasma from the rest of the blood. One uses a piece of equipment called a plasma filter, the other a device called a blood cell separator. Both methods are used at Great Ormond Street Hospital (GOSH). Your child’s medical team will make a decision based on various factors, including the size of your child and the nature of their illness.

Both methods require a special intravenous catheter to access the blood. For more information about this, please refer to our information on central venous haemodialysis catheters.


Blood is pumped around a machine and through the plasma filter. The holes in the filter are too small to allow blood cells to pass through, so the plasma is sieved out and collected. Replacement plasma is infused into the blood circuit and the whole blood returned to the child.

Cell separation

Blood is pumped into the cell separator, which spins around fast enough to create a centrifugal force that separates the plasma from the rest of the blood. The machine can then remove the plasma. Replacement plasma is infused into the blood circuit and the whole blood returned to the child.

Will it hurt?

The procedure does not hurt, but it may make your child feel tired. Your child may feel some discomfort when the intravenous access catheter is inserted but this will wear off.

How long will it take?

A plasma exchange takes about two to three hours, depending on the amount of plasma that needs to be removed. Your child will need to be connected to the plasma exchange machine, either sitting in bed or in a chair, but can play or do schoolwork as normal if they feel up to it. Your child can eat and drink during the procedure.

How many plasma exchanges will my child need?

This depends on your child’s medical condition. The doctor will usually recommend one exchange a day for a minimum of five days. More will be prescribed if the medical team feel this would be beneficial. The intravenous catheter will remain in place for as long as it is needed.

Where will it happen?

The procedure can be done anywhere in the hospital. If your child is well, the plasma exchange will usually be carried out on Eagle Ward, with other children who are undergoing similar procedures.

However, it may also be done by your child’s bedside.

Who will do the plasma exchange?

A nurse trained in the procedure will perform the treatment and stay with your child all the time.

Are there any risks associated with plasma exchange?

There is a small risk that your child may have an allergic reaction to the replacement plasma. Medication may be given before each exchange to minimise this risk.

Donated blood products will be used in the procedure. This will be mostly albumin (a vital protein in the blood stream) but will include some blood or plasma. There is a small risk that diseases can be passed on in this way, but every product used is screened according to recommendations from the transfusion service.

The exchange of large volumes of plasma may cause shifts of fluid, which can lead to changes in blood pressure, cold hands and feet or breathlessness. If the symptoms persist, your child’s medical team may recommend that the plasma exchange should be stopped.

Plasma exchange will lower or suppress the body’s immunity (its ability to fight disease). Over a few days this should not cause problems. However, if your child has already been treated with immunosuppressive drugs there is a greater risk of infection.

Are there any side effects from the procedure?

Possible side effects during the treatment include dizziness, nausea or a feeling of cold. If at any time during the procedure you or your child detect any symptoms, you should tell your child’s nurse. They will be able to adjust the procedure accordingly.

The nurse will also monitor your child’s vital signs (for example, blood pressure) during the plasma exchange, in order to detect any problems as quickly as possible.

Your child may feel tired after the plasma exchange.

How soon can I take my child home after the plasma exchange?

In most cases your child will receive plasma exchange as an inpatient, because the range of treatments prescribed for their condition requires a hospital stay. However, if they are able to go home, it is possible to come in to GOSH just for a day to have plasma exchange.

As long as there are no problems during the procedure, your child will be able to go home after a short rest.

Compiled by: 
Eagle Ward in collaboration with the Child and Family Information Group
Last review date: 
May 2012


Please note this is a generic GOSH information sheet. If you have specific questions about how this relates to your child, please ask your doctor. Please note this information may not necessarily reflect treatment at other hospitals..