BLOOD TRANSFUSION
A blood transfusion is when donated blood is given intravenously, directly into your
bloodstream. Usually it is a component of blood which is given.
Red blood cells contain haemoglobin which carries oxygen to your body tissues and organs.Your doctor will decide if you need a transfusion by considering the cause and severity of your anaemia (low haemoglobin), your medical condition and any symptoms.
Generally, if your haemoglobin is:
*below 70 g/L (grams per litre): a transfusion
is often needed
*between 70 and 100 g/L: transfusion may
be necessary
*above 100 g/L: transfusion is not
usually needed.
Platelets help blood to clot. A platelet transfusion may be needed when your platelet numbers are too low or when your platelets don’t work properly.
Plasma works with platelets to clot blood and seal wounds. It is often used in emergencies to help stop bleeding.
BUT, the most common treatment for all major forms of thalassemia is red blood cell transfusions. This is because there is enough total blood in the body, but not enough red blood cells to carry enough oxygen to the tissues. Most patients with a major form of thalassemia receive red blood cell transfusions every two to three weeks, amounting to as much as 52 pints of blood a year. Untreated, thalassemia major leads to heart failure and liver problems, and makes a person more likely to develop infections.
Where does the blood come from?
o To prevent disastrous reactions between the infused blood and the body's defenses, the blood must be typed and marked properly and found to be 'compatible' with the components of the recipient's body. The blood is usually from donors, where the blood has to undergo Microbiology test and Grouping test.
o Providing blood for yourself - Autologous collection
Patients sometimes ask if they can give their own blood before surgery, to be used
instead of donor blood. Although autologous collection and transfusion may sound riskfree,
it is not. Collection of your own blood before surgery is therefore not generally
recommended except in special situations, e.g. rare blood groups when it may be
difficult to obtain matched blood
o Artificial blood has been developed for many years but remains experimental and of doubtful benefit. As indicated above, young patients often can be resuscitated with plasma and other compounds to fill the circulation but there is no real replacement for blood. This means that without volunteer donors, the health care system would be helpless to treat a wide variety of illnesses.
o In some situations, a hormone which stimulates blood formation (erythropoietin, procrit, epogen) can be injected to increase the rate at which you make your own blood. This might prevent subsequent need for transfusion. In such situations, your doctor will wish to give you additional iron to be sure that deficiency of this does not limit blood production.
o It is possible to store blood from selected donors so that should you need blood, this material would be available for use. Published data indicate that these 'directed transfusions' are not safer than are those from our regular blood banks. Stored blood is good only for 3-5 weeks, so that the timing of the collection must be precise. Blood can be processed and frozen for future use. This requires some hours to reconstitute, and there is a loss of cells in the process. Storage is expensive and usually reserved for very rare blood types for which donors cannot readily be found.
What are the risks?
It is not risk free. Severe reactions to blood transfusions are very uncommon, but can result in major consequences and rarely, even death. Immune or allergic reactions may occur. There may be an increased risk of post-operative infection and longer length of hospital stay for surgical patients.
Mild skin reactions or fever occur occasionally (one to two reactions in every hundred
transfusions). Patients who receive regular transfusions are more at risk of such reactions.
Despite screening of all blood donations, the risk of transferring infectious agents (including
hepatitis virus, HIV and bacteria) cannot be ruled out completely. This risk is extremely low.
There are several dangers:
*If the blood is given very quickly such that the heart cannot pump the extra load, fluid may accumulate in the lungs;
*If the blood is incorrectly typed, or if there are components in the body that could not be detected during typing and 'cross matching', the transfused blood cells may be abruptly destroyed with consequent damage to the kidneys with severe illness in the recipient;
*Blood may be contaminated by bacteria during storage which will cause potentially fatal infections in the recipient;
Side effects
Most people who have a blood transfusion do not experience any side effects. But people can have reactions to any blood component. They might have this reaction during or after the transfusion, and some people don’t experience any effects until a few weeks or even months later.
Possible side effects include:
** Fever - Fever is by far the most common side effect of blood transfusions, accounting for more than 90 percent of all transfusion complications. In addition to a fever, some people have chills, shortness of breath, a headache, or nausea. The fever might begin during the transfusion or within the first 24 hours after the transfusion. It can be uncomfortable but is not usually dangerous. Tylenol® (acetaminophen) can often reduce the fever and other symptoms. This fever is often caused by attacks of your antibodies (proteins that protect your body from foreign substances) against white cells in the donated blood. To prevent fever, many blood banks filter out the white blood cells from their blood products. This process is called leukoreduction.
** Allergic reaction - Some patients have an allergic reaction to certain substances in the plasma of the donated blood. These patients often develop hives (also known as urticaria), which are itchy, swollen patches or bumps on the skin. They can also develop wheezing or swollen body tissues. Hives and other allergic symptoms are uncomfortable, but they are not dangerous and they usually go away after the patient takes antihistamines. If you develop an allergic reaction during or after a transfusion, you will probably be treated with an antihistamine beforehand if you have another transfusion.
** Alloimmunization - Sometimes a patient who has received many blood product transfusions develops antibodies against parts of the red blood cells or platelets in a donated unit of blood. This is called alloimmunization and when it happens, the transfused blood products do not work properly. However, alloimmunization does not always cause any symptoms. Alloimmunization can be prevented by giving patients red blood cells that do not have the antigens that the patient’s antibodies attacked or by filtering white blood cells out of the blood product.
** Transfusion-related acute lung injury (TRALI) - This reaction is very rare and very serious. It can even be life-threatening, especially if the patient is already very ill before the transfusion. You might have trouble breathing or develop a high fever. Medicines do not help but TRALI usually goes away by itself. The doctor might recommend oxygen and sometimes a breathing machine to help with the symptoms. If you have had TRALI after a previous transfusion, your doctor will try to prevent this from happening again by using diluted saltwater to remove most of the plasma from the blood.
** Hemolytic reaction - In this very rare condition, the patient’s antibodies attack the transfused red cells and damage or destroy them because the patient’s blood does not match the transfused blood.
o Acute immune hemolytic reaction - The reaction is acute if it happens during the transfusion. Symptoms can include chills, fever, pain in the chest and lower back, a rapid heartbeat, red or dark urine, and nausea. This is the most serious reaction that can happen after a blood transfusion because it can reduce the patient's blood pressure and cause potentially life-threatening bleeding or kidney damage. When a patient has an acute hemolytic reaction, the technician must stop the transfusion as soon as the reaction starts.
o Delayed hemolytic reaction - Hemolytic reactions can also happen gradually, within days or weeks of the transfusion. Symptoms can include a fever and jaundice (yellow skin and eyes), but some patients have no symptoms. This type of reaction is more likely to happen in someone who has had several transfusions before. If a person who has had a delayed hemolytic reaction needs another blood transfusion, the blood units that are transfused must be tested to make sure that they don’t contain the antigen that the patient’s antibodies attacked.
** Infections - In very rare cases, patients get an infection from the transfused blood. Every unit of blood that is donated is tested for bacteria, viruses, and parasites that can cause infections, but none of these tests is completely accurate. The types of infections that can be given to patients from donated blood include:
o Bacteria - Blood can be contaminated by tiny amounts of skin bacteria during the donation process. If patients receive platelets with these bacteria, they can become seriously ill soon after the transfusion starts. Since 2004, blood banks have tested platelets for bacteria before giving the platelets to patients.
o Hepatitis B and C - Hepatitis is the most common disease that can be transmitted by a blood transfusion, although this is extremely rare (the risk is less than 1 in 1 million). Viruses that attack the liver cause hepatitis B and C. Although hepatitis does not necessarily cause any symptoms, it can cause liver failure and other complications. To reduce the risk of transmitting hepatitis through blood transfusions, blood banks ask potential donors about their hepatitis symptoms and risk factors. Blood banks also test donated blood for hepatitis B and C viruses and liver problems that could be signs of other types of hepatitis. Patients can also reduce their risk of hepatitis B infection by getting the hepatitis B vaccine.
o Human immunodeficiency virus (HIV) - HIV is the virus that causes acquired immunodeficiency syndrome (AIDS). Blood banks routinely test every unit of donated blood for HIV and ask potential donors about their HIV risk factors and symptoms. As a result of these precautions, the risk of HIV transmission through a blood transfusion is extremely small—less than 1 in 1.9 million.
**Iron overload - because the hemoglobin in red blood cells is an iron-rich protein, regular blood transfusions can lead to a buildup of iron in the blood.
Consent
Patients must give consent(implied or expressed) before blood transfusion is done. The patient should give consent after understood reasons, risks, alternatives and benefits.
Links
1. http://www.caring4cancer.com/go/cancer/treatment/blood-transfusions/possible-side-effects-of-blood-transfusion.htm
2. http://www.drugs.com/enc/thalassemia.html
3. http://health.yahoo.com/blood-treatment/thalassemia-treatment-overview/healthwise--hw184724.html
4. http://www.personalmd.com/news/transfusion_10022000.shtml
5. http://www.transfusion.com.au/Consent-and-Risk/Consent-Checklist---Multicultural.aspx
6. www.pdn.gov.my/kh_pengenalan.html
7. http://www.nhlbi.nih.gov/health/dci/Diseases/Thalassemia/Thalassemia_Treatments.html
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