The nature, preparation, storage and usage of a blood component for transfusion - Essay Example

?Blood Transfusion: Usage of Blood component for transfusion Introduction: Blood transfusion can be explained very simply as the process of receivingblood intravenously. The earliest blood transfusions were experimented between humans with animal blood. After several experiments with mixed results, the first transfusion using human blood was done in 1795 and performed by American born physician Dr. Philip Syng Physick. The objective of a transfusion such as this is to usually replace blood components that the body has lost. Initial experiments with transfusions involved the usage of unprocessed blood, which is medically called “whole Blood”. Due to advancement in medical science however we are now able to replace the lost blood components by transfusion of just the components such as platelets, red blood corpuscles, white blood corpuscles and other factors. Several technical difficulties were faced by physicians in the transfusions of blood directly from one source to another due to the nature of blood and its inherent properties. We will discuss the challenges in the field of blood transfusion and the innovations that sought to face these challenges. This article will explore the subject of blood transfusions under the following divisions: 1. Nature of Blood 2. Different methods of transfusion. 3. Preparation of the blood for transfusion 4. Storage of the blood 5. Usage of the blood for transfusion. Nature of Blood: One of the most notable discoveries for the field of Blood Transfusions is the discovery of the various blood types by Karl Landsteiner between the years 1900 to 1901. This identification provided the answers for the failure of earlier methods of transfusions. The classification of blood type under the ABO groups based on the antigens present in the blood of the individual and the antibodies created by the blood in order to reject foreign elements in the blood. Mixing two non-compatible blood groups can cause the blood to coagulate and release toxins in to the body. This was the reason for the failure of previous attempts to transfuse blood. By his research findings all blood types were known to fall under the ABO category and classified thus as A- type, B-type, AB- type and O-Type blood groups. A-type blood groups had prominence of the A antigen and anti-B antibody and B-type had the reverse. These antibodies are the main elements that act towards rejecting or accepting a blood type. O type was found to have no antigens but both antibodies. Therefore it was termed as the Universal Donor but could only accept blood from another with the same blood type. AB group for instance had both antigens but no antibodies and therefore can be classified the Universal accepter of all blood types but can only donate to its own blood type. Further classifications were later made based on the discovery of the Rh factor in the blood. This discovery paved the path for future tremendous successes in blood transfusions as medical science now had a better idea of why their methods failed to work prior to this classification. Further research on blood and is components and properties lead to advancements in paternity tests. Different techniques of Blood Transfusions: The oldest and probably the most popular methods used for blood transfusions is Anastomosis (Keynes, 1922) in other words, Direct Transfusion intravenously. Blood is transfused between the radial artery of the donor to a median cephalic vein of the recipient. The radial artery in the wrist, although the most accessible is also the only available artery in the wrist and the median cephalic vein found at the elbow is also the most suitable for such a transfusion. Therefore it required a great amount of accuracy and provided some challenges in blood transfusion. The artery and vein in question are very small in nature and therefore it was a challenge for people in the medical profession to target it accurately and conduct the process within the limited time available. Blood has a natural tendency to coagulate outside of the human body; therefore it was necessary to perform this procedure very quickly within the limited window before this coagulation occurs. After various innovations by physicists the most popular technique that is in practise is now the Crile’s Method. “This depends on the use of a short silver tube, through which the end, of the artery is threaded. The artery is then pulled back again outside the tube in the form of a cuff and fixed in position. The end of the artery has thus been made rigid, and over this the vein is pulled in its turn and fixed by a ligature. A watertight junction is thus made, and blood can flow through it without interruption unless clotting takes place in the vessels as the result of handling and injury to their walls” (Keynes, 1922). Indirect Transfusion: One of the biggest challenges faced by medical scientists in blood transfusion is the speed in which the blood coagulates outside of the human body. Therefore direct transfusion involved not only technique but also extreme skill and dexterity. This problem was somewhat solved by mixing the blood with anti-coagulants to preserve it. Although the concept of a chemically treated blood may not be very appealing, it has been proven to be very effective and harmless by the usage of Sodium Citrate to treat the blood and prevent the coagulation. Levisohn discovered this method in the year 1915. This is probably one of the biggest innovations and brought about the existence of blood banks which could store blood of donors for use in future within a specified amount of time. Preparation of the blood for transfusion: To understand transfusion of blood components in place of Whole blood, it is necessary to understand the various components of our blood. The main components of our blood are: 1. Red cells or Erythrocytes. 2. White cells or Leukocytes 3. Platelets or Thrombocytes These three main components in our body are produced by stem cells stored in our bone marrow. These are formed from the inner cell mass of an embryo. Stem cells have the capacity to develop into any tissue in the body. All human beings children and adult alike have some specialized stem cells in their bone marrow and these function as, the main storehouses and production centres of the blood components in our body. 1. Red Blood cells or erythrocytes: These microscopic non-nucleic cells comprise of almost 50% of the blood components in our body. Their main function is to carry oxygen from the lungs to the living tissues in the body. “Haemoglobin is the gas transporting protein molecule that makes up 95% of a red cell.  Each red cell has about 270,000,000 iron-rich haemoglobin molecules.”(O’Neil, 2011). 2. White cells or Leukocytes: Our human blood is comprised of a very small yet essential part of out body’s cell composition. These comprise about only 1% in our blood and are not only restricted to the blood. They are the first respondents of our body’s immune system and are the law enforcers of our immune system as they seek out harmful virus, bacteria and fungi and remove them from the body. Their main function is to rid the body of dead cells and foreign material. 3. Platelets or Thrombocytes: These are no-nucleic cell fragments, which work together with other elements in our body that are related to blood clotting. The main reason, for blood clots are, due to the coagulating chemicals released by these cell fragments. The process of blood clotting is called Haemostasis. It is a defence mechanism developed by the body to prevent the free flow of blood outside of the body whenever there is an injury or rupture. When a portion of our body ruptures or is exposed, the exposed collagen pushes the platelets to adhere to prevent excessive flow of blood. Apart from these main components in our blood the human blood also consists of plasma, which is the carrying agent of the main components in our body. Plasma is a mix of yellow tinted water, sugar, fat, protein and salts and makes up about 55% of our blood volume (O’Neil, 2011). Their main function is to provide nourishment to the human blood and remove non-working waste products. The plasma also plays a role in the clotting of the blood. We will now examine the process of indirect transfusion methods where whole blood is drawn from the donor by the methods described in the previous section and then separated into the main components of the blood and prepared for use in transfusion at a later stage. Obstacles faced by the earlier methods of manual separation methods have been eliminated by the usage of advanced technology. Fully automated machines controlled by high-tech software programs now do the separation. The technique employs the use of storage bags connected to satellite bags, which are all connected to the additive solution. The whole blood is drawn into a sealed storage bag and centrifuged. The RPM of the centrifuge spin is adjusted according to requirement based on the standards set by the American Association of Blood Banks (AABB). First the red blood cells are separated from the platelet rich plasma stored separately in one of the storage bags that are connected by tubes. The separated red cells are then mixed with the additive solution and sealed and cut off from the sequence and stored. The sequence continues with the separation of plasma liquid from the platelets by similar centrifugal process. Whole blood is also mixed with additive substance and stored without separation. Many more additive substances have been found to be just as effective as Sodium Citrate and have been utilised. Storage of Blood Components: The red blood cells are stored at temperatures ranging between 1?C -6 ? C. The plasma obtained from the above mentioned centrifugal process is frozen. This frozen plasma can be used to make anti-haemophilic factor which is the essential component required for blood clotting. In the event that the blood needs to be transported the storage temperature is maintained between 1?C -10 ? C. The blood components thus stored can be preserved for about 20 days or a bit more depending on the nature of the additive solution used. Frozen red blood cells treated with Glycerol can be stored for almost 10 years of maintained at temperatures of - 65 ?C. However once the storage bags are opened the blood should be transfused within 24 hours. Usage of the blood for transfusion: Stored whole blood is used on people who experience active bleeding such as trauma victims who have lost more than 25% of their blood volume. Red blood cells find usage in increasing or adjusting the haemoglobin count of the patient. For example it has found extensive usage in cancer patients who are undergoing radio or chemotherapy, during surgery and in premature childbirths. In some cases the stored Red blood cells are sent through Leukocyte filters when administering to patients who have adverse reactions to white blood cells in the past. Final unit must have less than 5 x 106 WBCs (Kumar, et.al. 2006, p.174). Frozen red cells are processed to remove the glycerol preservative by running through a blood cell processor before administering to patient within 24 hours. Conclusion: The process of blood transfusion and the development of blood banking has been one of the greatest innovations of medical science. It has been helped along further more by the process of blood matching and finding the most compatible blood type for the patient. According to Wiley-Blackwell of Health news (2011), in the United States alone more than 5 million people receive blood transfusions annually. However there are still some reservations about usage of stored blood within the medical community. Indirect transfusion methods have eliminated some of the many technical issues related to fresh blood transfusion, and also considerably reduced the trauma aced by a blood donor who watches the transfusion of his or her own blood into another person’s body who lying side by side to them. There are still ongoing debates on the freshness of stored blood in comparison of fresh blood used in direct transfusion methods.  "Although emerging infectious disease risks and transfusion reactions are important concerns, there is nothing more imperative to our patients than making sure the methods we use to collect and store red cells do not impair their transport of vital respiratory gases." (Hopkins,) Recent research has shown that transfusion of stored blood products may increase the risk of blood clots and have the danger of heart failure. Dr. Mark T Gladwin, in his research ahs revealed that stored red blood cells cause the breakdown of red blood cells and the release of haemoglobin and micro-particles which get accumulated in the storage bag and when transfused into the patient can cause the break down and destruction of a very vital molecule that aids the normal flow of blood, NO. This destruction of NO causes the blood to constrict and affects blood flow within the body. Constricted flow of oxygen carrying blood results in the irregular flow and loss of oxygen to some parts of the body. This in turn activates the platelets and coagulation takes place within the body result in dangerous inflammations. At times stored red cells have been known to release an excess of haemoglobins which were found to react 1000 times faster in the destruction of NO than in fresh blood cells. (Science daily, 2011). Current regulations and standards introduced by the Food and Drug Administration (FDA) have guaranteed the appropriate storage methods and temperatures. There has not been any conclusive evidence of the dangers of stored blood transfusions. Medical investigations are still unable to relate patient deaths to transfusions of stored blood and blood components. Research is ongoing on alternate methods to eliminate the respiratory methods mentioned above. Blood transfusions in general have faced opposition from religious fanatics as well for various other reasons. Every innovation has to go through its litmus test. Transfusions using stored blood have had their own proven success rate and until proven otherwise, it remains one of the greatest innovations medical science has ever made. List of References Adriano Aguzzi & Markus Glatzel. (2006) “Nature Reviews Neurology 2”.321-329.   Meredith Wadman. “Blood transfusion for stem cell company? Red blood cells could provide new hope for beleaguered ACT”. Nature. 22 August 2008.Retrieved on March 07,2012 from Nature news online. Lewis J Kaplan . “Transfusion and Autotransfusion”. Nov 28, 2011. Retrieved on March 07.2012. http://emedicine.medscape.com/article/434176-overview Wang SS. “What's the Shelf Life of Blood? Focus on Whether Older Donations Impair Recovery of Transfusion Recipients”. 2009 Dec. 1. Retrieved March 07.2012. from The Wall Street Journal. H.Klein, D. Anstee (2005), "Mollison's Blood Transfusion in Clinical Medicine".p.406. C. Th Smit Sibinga, P. C. Das, Stichting Rode Kruis Bloedbank Groningen/Drente. Springer, (1989). “Automation in blood transfusion: proceedings of the Thirteenth International” "Homage to scientist on Blood Donor’s Day". June 15, 2006. Retrieved JMarch 07, 2012. from The Tribune. Geoffrey keynes,Ma. Md.(cantab), frcs.(eng.) (1922) “The techniques of blood transfusion. The Medical Front..Chapters from the Book Blood transfusion. Retrived on March 07, 2012.http://www.vlib.us/medical/transfusion/methods.htm The McGraw-Hill Companies, Inc. “Hemostasis”. Retrieved on March 07,2012. http://www.mhhe.com/biosci/esp/2002_general/Esp/folder_structure/tr/m1/s7/trm1s7_3.htm Rudmann, S. V. (2005). “Textbook of Blood Banking and Transfusion Medicine” 2nd Ed.. Philadelphia, PA: Elsevier Saunders. Blaney, K. D. and Howard, P. R. (2000). “Basic & Applied Concepts of Immunohematology”. St. Louis, MO. Mosby, Inc. Flynn, J. C. (1998). “Essentials of Immunohematology”.Leucodepletion and Blood Products. Wiley-Blackwell.  “Safety of stored blood among chief concerns for transfusion medicine community: Medical literature addresses possible adverse effects with older red cells; delivery of oxygen”. 15-Apr-2011. Retrieved on March 07, 2012. from http://www.eurekalert.org/pub_releases/2011-04/w-sos041211.php ScienceDaily. “Safety of Stored Blood Among Chief Concerns for Transfusion Medicine Community”. Apr. 15, 2011. Retrieved on March 07, 2012. http://www.sciencedaily.com/releases/2011/04/110415083140.htm Read More