Overview

Sickle cell disease (SCD) is a condition that effects the body’s red blood cells. It is an inherited condition, and is and lifelong. It is also known as sickle cell disorder.  

A exchange blood transfusion (EBT) is a treatment used for SCD. 

Blood

Blood is made up of different types of blood cells and plasma (a straw-coloured liquid, which carries the blood cells around your body).

The different types of blood cells are:

• red cells, which contain haemoglobin (the red pigment which carries oxygen to, and carbon dioxide from, the rest of the body)
• white cells, which fight infection
• platelets, which are clotting cells

The adult human body contains about 5 litres of blood. Usually, red cells last about 120 days (about 4 months) in the blood. They last for a shorter time in people with SCD. The red cells are then removed by the body, which means that your body always needs to replace them.

How a blood transfusion works

A blood transfusion is a procedure that puts red cells into your body. This could be a routine (planned) procedure, or be done in an emergency situation.

During an EBT, sickle blood is replaced with blood from a donor who does not have SCD.

A simple blood transfusion (also known as a top-up) is another type of blood transfusion used for SCD. During a simple blood transfusion, a few units (bags) of blood are given through a small tube (drip), usually placed in a vein through your arm. 

Why an EBT is needed

An EBT might be needed in an emergency for a:

• complicated sickle cell crisis, such as a stroke 
• chest crisis (sickling in the lungs which causes breathing problems)
• very painful sickle cell crisis

A routine or planned exchange transfusion may also be done if:

• you have had a stroke, as repeated exchange transfusions can help reduce the risk of further strokes happening
• your SCD is very severe, as repeated exchange transfusions can help reduce the number of crises
• you are pregnant, to prevent any complications affecting you and your baby
• you are going to have a major operation, such as a hip replacement. A single exchange transfusion reduces the risk of complications from the general anaesthetic and surgery
• you have leg ulcers, as exchange transfusions may help the healing process
• you have severe priapism (painful erections) that has not responded to other forms of treatment or surgery

Repeat exchanges

Some patients will be put on exchange blood transfusions regularly, for example every 6 to 8 weeks. This is known as repeat exchanges.

Usually, red blood cells only live for 120 days (4 months)  in your body. Repeat exchanges are needed to keep the amount of sickle cells in your blood to a low level. The frequency of the exchanges depends on the reason for exchange, but can range between 4 and 14 weeks.

Benefits of an EBT

Some of the benefits of having an EBT are the same as for a simple (top-up) transfusion, such as:

• feeling more healthy
• having fewer problems with your SCD
• preventing problems, such as if you are at risk of a stroke

Risks of an EBT

As with any procedure, having a EBT does have some risks and side effects, and it is important that you understand them. 

Blood safety

In the United Kingdom, we take many precautions to make sure any blood given to you is as safe as possible.

The main risk from a transfusion is that you could be given the wrong blood by accident. To make sure you receive the right blood, the clinical staff must make careful identification checks. They will ask you to state your full name and date of birth and will check the details on your name band. This is to make sure you receive the correct blood. They will also regularly monitor you during the transfusion (check your blood pressure, temperature, pulse and breathing rate). 

The risk of contracting a disease, such as hepatitis B and C, or human immunodeficiency virus (HIV) is extremely low. 

• The risk of getting hepatitis B is about 1 in 900,000 and 1 in 30 million for hepatitis C.
• The chance of HIV infection from a blood transfusion is less than 1 in 6.5 million.

Creutzfeldt-Jakob disease  is a rare, uncurable brain disease. The possibility of a blood transfusion transmitting variant Creutzfeldt-Jakob disease is extremely small and precautions are taken to reduce this risk.

We now strongly advise that all patients on a transfusion programme are routinely vaccinated against hepatitis B. During the transfusion programme, your immunity to hepatitis B and other viral infections will be regularly reviewed. 

Although the risk of contracting an infection from blood is very low, we recommend that we check you for HIV and hepatitis C infection once a year.

Antibodies against the donor blood

Your blood is matched very closely with the blood of the donor (the person who donated the blood). However, it is possible to develop antibodies against the donor blood, so you need to make the clinical staff aware of any symptoms you may be having after the transfusion. These antibodies can mean that matched blood is harder to find and can take longer to prepare.

If you have developed antibodies, you will be sent an alert card that says ‘I need special blood’.  This is to help make sure that anyone treating you knows that your blood needs to be matched against them. Please make sure you show this to clinical staff before you receive a transfusion and in any hospital where you are treated.

Side effects

After you have had an EBT, you may notice some side effects, such as:

• light headedness and fainting
• bone pain
• tiredness, for a day or 2 after the transfusion

Other side effects include: 

Skin rash

You might get a skin rash. This can be treated with antihistamines.

High temperature (fever)

You may get a high temperature (fever). This can usually be treated with paracetamol.

Iron overload (receiving too much iron)

This is common in people who receive repeated blood transfusions. If needed, excess iron can be removed by taking medicine (injections or tablets). This is much less likely to happen if the exchange machine is used for your transfusion, compared to it being done manually.

Tingling sensation in your lips and fingers

This because of the anticoagulant (blood thinning fluid) used, which lowers calcium levels in your blood. We might give you calcium tablets, or a magnesium infusion through your inserted line, during the procedure to prevent this.

Low platelet count

Your platelet count could be lowered by the exchange transfusion. However, as most people with SCD have high platelets, your platelet count will usually remain within the normal range. This will increase back to your usual level in the days after the exchange.

Delayed transfusion reactions 

Sometimes, a patient has a delayed transfusion reaction. This is where your body abnormally breaks down the blood you have been transfused. This may happen in the first 2 weeks after you have had an EBT.

If you do not want a blood transfusion

Some people do not want to have blood transfusions, for various reasons.

We would encourage you to discuss any concerns you have about blood transfusions with the sickle team. This is important if you have had severe complications of your SCD before, or are planning a pregnancy or an operation. This is to allow the haematologist looking after you to consider if there are any alternative treatments that could be offered.

The haematologist will make sure your wishes are included in your medical notes. This will be shared with other medical professionals who may be involved in your care to form a plan. We would also encourage you to discuss your objections or wishes with your family members, and in particular your legal next of kin. This is because they may be asked about your wishes regarding blood transfusion if you become unwell. 

Asking for your consent (permission)

We want to involve you in all the decisions about your care and treatment. It is entirely your choice whether to have the transfusion programme or not. We will give you relevant information to help you come to a decision with the sickle cell team. It is important that you understand the information and have the time to ask questions and to make your decision. 

If you agree to have an EBT you will be asked to sign a consent form. This confirms that you understand what the treatment involves and agree to have it.

If you have agreed to repeated exchange blood transfusion (for instance, to help prevent further strokes), your consent will be reviewed at least every 6 months. It is up to you if you want to stop the transfusions. If you do, it is important to discuss this with your haematologist, so that you are clear about how your decision may affect you. Other suitable treatments for you can also be discussed and offered to you at this time.  

Read more about our consent process.