Learn about blood transfusion

14th June is the World, “BLOOD TRANSFUSION”, DAY. It is a day to remind people of the importance of blood transfusion. In times of need, blood transfusion is a life giving procedure, which if delayed can risk the life of the affected person. Apart from life, loss of or severe lack of adequate blood can compromise blood supply to vital parts of the body like heart, brain, limbs, e.t.c., thus compromising their function. Blood transfusion implies giving of human blood to a person needing it. The person in need of the transfusion may have severe chronic anemia (lack of adequate blood) due to nutritional deficiency, causing damage to body parts like the heart, kidneys, limbs e.t.c. An individual may have lost large amount of blood in a road accident or some other type of injury. Blood may have been lost during a major surgery. These are different situations which necessitate giving of blood immediately to the affected person, to prevent shock and even sudden death due to loss of large amounts of blood. The first successful blood transfusion documented in history was done by Dr. Jean Baptiste Denys of France, a physician to King Louis xiv of France. He transfused blood of a sheep into a 15 year old boy on 15th June 1667 and the boy survived. Maybe the amount of blood transfused was small and thus the boy did not get anaphylaxis, i.e. severe allergic reaction. Since that time, knowledge regarding blood and its components and techniques of transfusion has improved much. Before, it was always blood freshly drawn from a potential donor and given to the person needing it. Later on, it was discovered that by adding chemicals to prevent clotting of blood, it can be drawn and kept up to a certain shelf life and used whenever necessary. Thus the concept of blood banks started, where blood is stored in freezing conditions to be used whenever required. Later technology has evolved where transfusion of components is possible. Thus as per the situation concerning blood loss, a person may receive only concentrated red blood cells or platetelets. Auto transfusion, where an individual’s own blood is withdrawn and then given to him again is also possible. Though blood transfusion is life giving and mandatory in situations where it is needed, there are many limitations to it. First is the availability of blood. There is no wholly successful substitute of natural human blood. Volume expanders like dextran are used to expand plasma volume to maintain blood volume and prevent shock. But they do not supply oxygen to body cells like blood .Substances like Haemopure or Purehaem are available to help maintain the blood volume and also supply oxygen to body cells. But they do not provide other benefits of natural whole blood like supplying white blood cells to combat infection. Many people are scared of donating blood, fearing weakness. Any healthy individual can donate blood with no resultant weakness. The amount of blood he gives shall be formed within 3 weeks wholly again. Another issue is the availability of compatible blood. There are certain blood groups (antigens), which are present differently in different individuals. These are labeled as A, B, O and AB, which are again positive or negative. A person has to receive transfusion with a blood which is compatible with his blood group. For example a person with blood group A positive has to be transfused by A positive blood only. Otherwise, there can be a fatal reaction. Also with transfusion of same group blood also, certain individuals may develop allergic reactions, joint pains, rigors, mild jaundice, fever all can occur following blood transfusion. Along with blood, many infections can also pass on to the person receiving transfusion. Sepsis, malaria, hepatitis B and C, syphilis, HIV, all these infections can be transmitted through blood, if blood from an infected individual is given to another individual. Therefore it is important to screen blood to be transfused for these infections. In Rwanda, control of blood stored in blood banks is very good in this regard. The risk of reactions to blood transfusion increases with the number of transfusions. In case of people suffering from disorders of hemoglobin or blood like G6pd deficiency, sickle cell anemia, and receiving multiple transfusions, carry high risk of developing allergies and infections due to transfusion. Some religious groups like Jehova’s witness oppose blood transfusion, maybe due to the associated risks .It should be remembered that blood transfusion has to be done very prudently where it is absolutely necessary and in those situations, there is no alternative. rachna212002@yahoo.co.uk