Plasma
Plasma, a yellow fluid, is the liquid part of the blood. It helps the flow of blood cells and carries proteins and other substances around the body.
Plasma exchange
Plasma exchange is a procedure in which your blood is separated into its different parts: red cells, white cells, platelets and plasma. The plasma is then removed from the blood and a plasma substitute returned in its place.
Why plasma exchange may be done
In conditions such as myeloma and Waldenström’s macroglobulinaemia, abnormal plasma cells may make large amounts of a protein called immunoglobulin. If the levels of immunoglobulin in the blood become very high, the blood can become thicker than normal, causing symptoms such as headaches, blurred vision and tiredness. This is sometimes called hyperviscosity syndrome.
Plasma exchange can reduce the amount of abnormal protein in the blood and so improve symptoms. It does not stop the protein being produced, however, and so it is often necessary to have other treatment, such as chemotherapy, to reduce the production of the protein.
People with acute or chronic myeloid leukaemia, who have a very high white blood cell count, may sometimes need a plasma exchange to help reduce the number of white blood cells in their blood.
How plasma exchange is done
Plasma exchange is carried out using a machine called a cell separator, which can separate out blood cells and plasma. A needle is usually inserted into a vein in each arm. Blood is taken from a vein in one of your arms and circulated through the cell separator. This separates off the plasma and the rest of your blood is returned into your vein through the needle in your other arm.
To replace the plasma that is removed a plasma substitute is given with the returned blood cells. As blood is being taken from you and returned to you at the same rate only a small amount of blood is outside your body at any time.
Each plasma exchange takes about two hours. The rate of plasma exchange is decided according to your height, weight and the thickness (viscosity) of your blood. The number of plasma exchanges that you need will depend on the amount of protein in your blood, your symptoms and your response to other treatments such as chemotherapy.
Possible side effects
Feeling faint or light-headed Occasionally people feel faint or light-headed during plasma exchange. If this occurs let your nurse or doctor know immediately. It is usually easy to treat by helping you to change your position so that you are lying down. You may be given additional fluid into the vein.
Try to eat breakfast and lunch on the day of treatment as this can help to reduce the chances of you feeling faint.
Numbness and tingling You may feel numbness or tingling around your mouth and nose or in your fingers during the treatment. This is a side effect of a substance called citrate. Citrate will be mixed with your blood to stop it clotting while it is outside your body. If the amount of citrate builds up it can temporarily affect the levels of calcium in your blood and cause the above symptoms.
Let the nurse or doctor know right away if you feel numbness or tingling sensations. It is easy to treat them either by stopping the plasma exchange for about five minutes or by giving you a milky drink. This is usually enough time for your body to readjust to the effects of citrate and for the symptoms to go away. Eating foods rich in calcium, such as milk, cheese and yoghurt, for breakfast or lunch before the plasma exchange, may help to reduce numbness or tingling sensations during treatment.
Additional information
If anything is worrying you about the procedure, speak to the nurse or doctor carrying out the treatment, as they may be able to help. For example, if you are anxious about needles it may be possible to have a local anaesthetic cream applied to numb the skin where they are to be put in.
You may want to bring in magazines or a book to read to help pass the time. It is normally possible to have a friend or relative accompany you during the procedure.
Drinking plenty of fluids (2–3 litres) on the day of the treatment will help to replace any fluid that you may have lost during the procedure. You may also want to avoid alcohol for the remainder of the day, as its effect on the body will be stronger than usual.
Some medicines can affect plasma exchange. Let your doctor or nurse know about any medications you are taking, including non-prescribed drugs such as complementary therapies and herbal drugs.
Once you are having plasma exchange it is difficult to move around so you may want to go to the toilet to empty your bladder before the treatment begins.
People often feel very tired after plasma exchange and you may feel tired for the rest of the day. It is best to rest afterwards and to avoid physically strenuous activity. It is also a good idea to arrange to have someone take you home rather than to drive home after treatment.
References
This section has been compiled using information from a number of reliable sources including:
- Guidelines for the Clinical Use of Blood Cell Separators. The joint working party of the Transfusion and Clinical Haematology Task Forces of the British Committee for Standards in Haematology, 1998.
- Guidelines on the Diagnosis and Therapy of Waldenström’s Macroglobulinaemia. British Society of Clinical Haematology, 2000.
For further references, please see general bibliography.
Via: http://www.cancerbackup.org.uk
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