Blood transfusions
Blood transfusions may be required for various medical conditions and are given when your body requires more blood cells. A blood transfusion contains mostly red blood cells and a liquid called plasma. The effects of a blood transfusion are only temporary as red blood cells survive for an average of 120 days, and need to be replaced.
Red blood cells
Red blood cells carry oxygen to the organs of the body by binding it to an iron containing protein called haemoglobin (Hb). In adults, normal Hb levels are 130-180g/L for males, and 120-160g/L for females. Red blood cells give blood its red colour and your skin its pink colour. The percentage of red blood cells in your blood is called the haematocrit (Hct).
Anaemia
Anaemia is a low red cell count or haemoglobin (Hb) and is common in many of the blood cancers or as a result of treatment. Signs of anaemia include fatigue, shortness of breath and pale skin.
Why people may need a blood transfusion
A blood transfusion may be given to correct the effects of anaemia symptoms and to improve healing and a person’s sense of wellbeing.
Where blood transfusions come from
People usually receive blood from anonymous blood donors. One blood donation generally gives three blood products – red blood cells, plasma and platelets. In Australia, every blood donation is tested for a variety of bacteria and viruses including human immunodeficiency virus (HIV), hepatitis and human T-lymphotropic virus type I (HTLV-1).
Receiving a blood product transfusion
Before accepting a blood product transfusion, it is important your doctor explains both the benefits and the risks to you. You may be required to sign a consent form. Your doctor prescribes the appropriate blood product for you on your medication chart, and states the time it will take to be administered by nursing staff. Your blood is then cross-matched in a laboratory (see next section) and the blood product is issued from the hospital, day centre pathology or blood bank.
Two nurses will check the blood in your presence, to ensure you are the correct person to receive the product being checked, and that all details are accurate, including your blood type. A blood transfusion usually takes 1-4 hours to infuse.
Cross-matching
Cross-matching is a process where a small sample of blood is taken from an intended blood product recipient (usually from a vein in their arm) then sent to a laboratory to determine compatibility with available donor blood (i.e., the blood that is in the blood bank).
The red cell blood group (known as ABO and RH types) and other antigens (cell markers) on the recipient’s red cells need to be determined and the recipient’s antibodies to the donor’s red cells are checked. This is known as a ‘group and screen’ or a ‘group and hold’.
The cross-match process is important, as a mismatch of blood can be life threatening. When a match is found between the recipient and donor blood types, the donated blood is labelled with the details of the recipient and is ready to be transfused to the patient. Usually, a cross-match is only accurate for 72 hours, then the process needs to be carried out again if blood is still required.
Side-effects
Despite the correct matching of blood, reactions to blood products are still possible. Signs that you may be having a blood transfusion reaction include shortness of breath, palpitations, fever, chills, skin rash, hives and/or itchiness.
Transfusion reactions are managed well with antihistamine medications and by discontinuing the blood transfusion, either until the symptoms have subsided or completely cease. Your nurse will take your blood pressure, pulse and temperature before and several times during the transfusion. If you have a question at any time before or during a transfusion, ask your healthcare professional. Source: www.transfusion.com.au (Australian Red Cross).
Platelet transfusions
Platelet transfusions may be required for various medical conditions and are given when your body requires more platelets.The effects of a blood transfusion are only temporary unless your body begins to produce enough of its own platelets.
Platelets
Platelets are actually cell fragments formed from a large cell called a megakaryocyte. The role of platelets is to ensure our blood clots, to prevent us bleeding to death. Platelets live for 8-10 days, which is why a platelet transfusion can tend to be given more frequently then a blood transfusion.
Thrombocytopaenia
Thrombocytopaenia is a low platelet count and can result from bone marrow cancer, autoimmune disease, infection or treatment such as chemotherapy.
Aim of platelet transfusion
A platelet transfusion is aimed at stopping bleeding and is commonly given to people with a low platelet count, poor functioning platelets, or those at risk of bleeding.
Where platelet donations come from
People usually receive platelets from anonymous blood donors. Each blood donation generally provides three blood products – red blood cells, plasma, and platelets. Every blood donation is tested for a variety of bacteria and viruses, including human immunodeficiency virus (HIV), hepatitis and human T-lymphotropic virus type 1 (HTLV-1).Bags of donated platelets need to remain in motion, or they can form clumps. For this reason, platelets are stored on an agitator (gently vibrates from side to side) and the product needs to be used soon after being removed.
Receiving a platelet transfusion
Before accepting a platelet transfusion, it is important your doctor explains both the benefits and the risks to you. You may be required to sign a consent form.
Your doctor then prescribes the platelets for you on your medication chart, and states the time it will take to be administered by nursing staff. Then your blood is cross-matched (see next paragraph) and the platelets are issued from the hospital or day centre pathology. Prior to receiving platelets, the nurses will check that you are the correct person to receive that particular product.
Cross-matching
Cross-matching is a process where a small sample of blood is taken from the person requiring the platelet transfusion and sent to a laboratory to determine compatibility with available donor platelets in the blood bank.
The cross-match process is important, as a mismatch of blood products can be life threatening. Once a match is found between the recipient and donor blood types, the platelets are then labelled with the details of the recipient and is ready to be transfused to the patient. Usually, a cross-match lasts only 72 hours, then the process needs to be carried out again if platelets are still required.
Side-effects
Despite the correct matching of platelets, reactions are still possible. Signs that you may be having a transfusion reaction include shortness of breath, palpitations, fever, chills, skin rash, hives and/or itchiness.
Transfusion reactions are managed well with antihistamine medications, sometimes with steroids, and by discontinuing the transfusion, either until the symptoms have subsided or completely cease. Your nurse will take your blood pressure, pulse and temperature before and several times during the transfusion.
If you have a question at any time before or during a transfusion, ask your health care professional.
Source: www.transfusion.com.au (Australian Red Cross).
Immunoglobulins
Immunoglobulins are antibodies made by plasma cells. Plasma cells are activated B-cells – a specialised white blood cell which is a vital part of your immune system. Antibodies are effective at defending the body against bacteria and other microorganisms.
Immunoglobulin infusions may be required for various medical conditions and may be given when your body requires help to fight infections and if your immune system (ability to fight infections) is compromised due to treatment or illness.
The effects of immunoglobulin may be only temporary, unless your body begins to produce enough of its own antibodies.
Where immunoglobulin comes from
Immunoglobulins are found in the liquid part of blood, called plasma. Plasma is collected (mostly by the Red Cross Blood Service) from a variety of donors, and then pooled or mixed together.
The first step in immunoglobulin production is to take blood from a donor, remove all the red cells, white blood cells and platelets, and return these to the donor. The plasma, containing immunoglobulins, is collected and this process is called plasmapheresis. The immunoglobulins are then chemically treated and much of the plasma is removed. This process results in the purification and concentration of antibodies in the final product.
The different types of intravenous immunoglobulin products available are Intragam (from Australian donors), Octogam, and Kiovig (both from European and USA donors).
Receiving a blood product transfusion
Before you accept a blood product transfusion, such as immunoglobulin, it is important your doctor explains both the benefits and the risks to you.
Your doctor prescribes immunoglobulin for you on your medication chart, and states the time it will take to be administered by nursing staff. Immunoglobulin is issued from the hospital, day centre pathology or blood bank.
Prior to receiving any blood product the nurses will check that you are the correct person to receive it. A transfusion of immunoglobulin usually takes several hours.
Side-effects
Reactions to immunoglobulin are possible. Signs that you may be having a transfusion reaction include shortness of breath, palpitations, fever, chills, skin rash, hives, itchiness, headache, and a drop in blood pressure. Transfusions reactions are managed well with antihistamine medications and maybe a steroid. The transfusion will be discontinued until your symptoms cease, and may be restarted at a slower rate and with close supervision. Your nurse will take your blood pressure, pulse and temperature before and several times during the transfusion.
If you have a question at any time before or during a transfusion, ask your health care professional.
Sources: www.transfusion.com.au (Australian Red Cross).
www.primaryimmune.org (Immune Deficiency Foundation)
Growth factors
All normal blood cells have a limited survival in circulation and need to be replaced on a continual basis.
This means that the bone marrow remains a very active tissue throughout your life. Natural chemicals in your blood called growth factors or cytokines control the process of blood cell formation. Different growth factors stimulate the stem cells in the bone marrow to produce different types of blood cells.
The growth factor that stimulates the production and maturation of red blood cells is called erythropoietin. This is mainly produced in the kidneys.
The growth factor that stimulates the production of platelets is called thrombopoietin and it is mainly produced in the liver and the kidneys.
Various cytokines stimulate the production of the white blood cells.
These days some growth factors can be made in the laboratory (synthesised) and are available for use in people with blood disorders. For example, granulocyte-colony stimulating factor(G-CSF) stimulates the production of white cells called neutrophils while erythropoeitin (EPO) stimulates the production of red cells.