Hi, I'm a Pathologist working in
My Committments right now are
The TN Dr.MGR Medical University
Surgical Pathology
Cardiac Pathology
Haematology research
Pathology of arthroscopic biopsy
My work involves dealing with blood and blood related products. I work in the Centre of Excellence for producing blood components like packed cells, FFP, platelets, etc., and developing a Centre for research and Development in Immunohaematology.
Do contact me at Dept of Transfusion Medicine - 2301871. Residence - 4728821, 3721527. Please come back and visit again! Feel free to offer your comments on this website. This is a site that is updated every fortnight. Mail me at ksc@md3.vsnl.net.in, csrikumar@hotmail.com or pathologist@rediffmail.com.
How much blood is donated each year? How much blood is transfused each year?*
About 12.6 million units (including approximately 643,000 autologous donations) of Whole Blood are donated each year by approximately eight million volunteer blood donors. These units are transfused to about four million patients per year. Typically, each donated unit of blood, referred to as Whole Blood, is separated into multiple components, such as Red Blood Cells, Plasma and Platelets. Each component is generally transfused to a different individual, each with different needs. The need for blood is great--on any given day, approximately 32,000 units of Red Blood Cells are needed. Accident victims, people undergoing surgery and patients receiving treatment for leukemia, cancer or other diseases, such as sickle cell disease and thalassemia, all utilize blood. More than 23 million units of blood components are transfused every year.
Less than 5 percent of healthy Indians eligible to donate blood, actually donate each year. According to studies, the average donor is a college-educated male, between the ages of 30 and 50, who is married and has an above-average income. However, a broad cross-section of the population donates every day. Furthermore, these “average” statistics are changing, and women and minority groups are volunteering to donate in increasing numbers. While persons 65 years and older compose 13 percent of the population, they use 25 percent of all blood units transfused. Using current screening and donation procedures, a growing number of blood banks have found blood donation by seniors to be safe and practical. Patients scheduled for surgery may be eligible to donate blood for themselves, a process known as autologous blood donation. In the weeks before non-emergency surgery, an autologous donor may be able to donate blood that will be stored until the surgical procedure.
There are many places where blood donations can be made. Bloodmobiles (mobile blood drives on specially constructed buses) travel to high schools, colleges, churches and community organizations. People can also donate at community blood centers and hospital-based donor centers. Many people donate at blood drives at their place of work. Community blood centers collect approximately 88 percent of the nation's blood, and hospital-based donor centers account for the other 12 percent. Consult the yellow pages to locate a nearby blood center or hospital to donate.
To be eligible to donate blood, a person must generally be at least years of age (although some states permit younger people to donate with parental consent); be in good health; and weigh at least 45 kgs . Most blood banks have no upper age limit. All donors must pass the physical and health history examinations given prior to donation. Nearly all blood used for transfusion is drawn from volunteer donors. The donor's body replenishes the fluid lost from donation in 24 hours. It may take up to two months to replace the lost Red Blood Cells. Whole blood can be donated once every eight weeks.
An increasingly common procedure is apheresis, or the process of removing a specific component of the blood, such as platelets, and returning the remaining components, such as Red Blood Cells and Plasma, to the donor. This process allows more of one particular part of the blood to be collected than could be separated from a unit of Whole Blood. Apheresis is also performed to collect Plasma (liquid part of the blood) and Granulocytes (White Blood Cells). The apheresis donation procedure takes longer than Whole Blood donation. A Whole Blood donation takes about 10-20 minutes to collect the blood, while an apheresis donation may take about one to two hours.
After blood is drawn, it is tested for ABO group (blood type) and Rh type (positive or negative), as well as for any unexpected Red Blood Cell antibodies that may cause problems in the recipient. Screening tests are also performed for evidence of donor infection with hepatitis viruses B and C, human immunodeficiency viruses (HIV) 1 and 2, human T-lymphotropic viruses (HTLV) I and II and syphilis. The specific tests performed are listed below: Hepatitis B surface antigen (HBsAg) Hepatitis B core antibody (anti-HBc) Hepatitis C virus antibody (anti-HCV) HIV-1 and HIV-2 antibody (anti-HIV-1 and anti-HIV-2) HIV p24 antigen HTLV-I and HTLV-II antibody (anti-HTLV-I and anti-HTLV-II) Serologic test for syphilis Nucleic Acid Amplification Testing (NAT) Note: NAT is still a research initiative and many blood collection organizations are pursuing implementation under the FDA’s Investigational New Drug (IND) application process.
Each unit of whole blood is normally separated into several components. Red Blood Cells may be stored under refrigeration for a maximum of 42 days, or they may be frozen for up to 10 years. Red cells carry oxygen and are used to treat anemia. Platelets are important in the control of bleeding and are generally used in patients with leukemia and other forms of cancer. Platelets are stored at room temperature and may be kept for a maximum of five days. Fresh Frozen Plasma, used to control bleeding due to low levels of some clotting factors, is usually kept in the frozen state for up to one year. Cryoprecipitated AHF, which contains only a few specific clotting factors, is made from Fresh Frozen Plasma and may be stored frozen for up to one year. Granulocytes are sometimes used to fight infections, although their efficacy is not well-established. They must be transfused within 24 hours of donation. Other products manufactured from blood include albumin, immune globulin, specific immune globulins and clotting factor concentrates. These blood products are commonly made by commercial manufacturers.
While donated blood is free, there are significant costs associated with collecting, testing, preparing components, storing and shipping blood, recruiting and educating donors and quality assurance. As a result, processing fees are charged to recover costs. Processing fees for the individual blood components vary considerably. Processing fees for one specific component may also vary in different geographic regions. Hospitals charge for any additional testing that may be required, such as the crossmatch, as well as for the administration of the blood.
While blood donors are needed throughout the year, they are most needed during holidays and in the summer. It is during these times that the number of donations declines while the demand continues or even increases. While a given individual may be unable to donate, they may be able to recruit a suitable donor. Relatives and friends of a patient requiring a blood transfusion may wish to help their loved one. Donating blood to replenish the units that were needed is one of the best gifts one can give. *Data provided by the National Blood Data Resource Center for 1997.
Education
When prospective donors enter a blood bank, they are asked to read educational materials such as the AABB pamphlet entitled “An Important Message to All Blood Donors.” These materials contain information on the risks of infectious diseases transmitted by blood transfusion, including the signs and symptoms of AIDS. Prospective donors are asked to acknowledge in writing that they have read and understood these materials, have been given the opportunity to ask questions, and have provided accurate information. The prospective donor can elect to leave at this point without donating. (Self-deferral can occur at any point in the donation process when a donor voluntarily chooses not to complete the process.)
If the prospective donor does not self-defer, he or she proceeds to the next step – giving a detailed health history. The history is designed to ask questions that protect the health of both the donor and the recipient. To ensure that every donor is asked the same questions, the AABB recommends use of a uniform donor history questionnaire. However, donor centers often create their own questionnaires using the same general guidelines. In addition to questions about transfusion-transmissible diseases, prospective donors are asked questions to determine whether donating blood might endanger their health. If a prospective donor responds positively to any of these questions, he or she will be “deferred” or asked not to donate blood. The health history is also used to identify prospective donors who have been exposed to, or who may have diseases such as, human immunodeficiency virus (HIV), hepatitis or malaria. These individuals are further evaluated and may be deferred.
The next step in the donation process is an abbreviated physical examination that includes checking the blood pressure, pulse and temperature. A few drops of blood are taken from a finger or an earlobe to ensure that anemia is not present. Abnormalities found in any part of the physical examination may be a cause for deferral.
Prospective donors who pass successfully through these steps proceed to the actual whole blood donation process, which takes about 20 minutes. The donor sits in a reclining chair. The skin covering the inner part of the elbow joint is cleansed. A new, sterile needle connected to plastic tubing and a blood bag is inserted into an arm vein. The donor is asked to repeatedly squeeze his or her hand to help blood flow from the vein into the blood bag. Typically, one unit of blood, roughly equivalent to a pint, is collected. After the blood is collected, it is sent to the laboratory for testing and component preparation. The donor is escorted to an observation area for light refreshments and a brief rest period. Adult males have about 12 pints of blood in their circulation and adult females have about nine pints. The donor's body replenishes the fluid lost from donation in about 24 hours. The Red Blood Cells that are lost are generally replaced in a few weeks. Whole Blood can be donated once every eight weeks.
Individuals who are disqualified as blood donors are said to be “deferred.” A prospective donor may be deferred at any point during the collection and testing process. Whether or not a person is deferred temporarily or permanently will depend on the specific reason for disqualification (eg, a person may be deferred temporarily because of anemia, a condition that is usually reversible). If a person is to be deferred for the protection of the blood recipient, his or her name is entered into a list of deferred donors maintained by the blood center, often known as the “deferral registry.” If a deferred donor attempts to give blood before the end of the deferral period, the donor would not be accepted for donation. At the end of a temporary deferral period, the donor may return to the blood bank, and, if the reason for the original deferral no longer exists, can be re-entered into the system.
Blood may be transfused as Whole Blood or as one of its components. Because patients seldom require all of the components of Whole Blood, it makes sense to transfuse only that portion needed by the patient for a specific condition or disease. This treatment, referred to as “blood component therapy,” allows several patients to benefit from one unit of donated Whole Blood. Blood components include Red Blood Cells, Plasma, Platelets and Cryoprecipitated Antihemophilic Factor (AHF). Up to four components may be derived from one unit of blood. Improvements in cell preservative solutions over the last 15 years have increased the shelf-life of Red Blood Cells from 21 to 42 days.
Whole Blood is a living tissue that circulates through the heart, arteries, veins and capillaries carrying nourishment, electrolytes, hormones, vitamins, antibodies, heat and oxygen to the body's tissues. Whole Blood contains Red Blood Cells, White Blood Cells and Platelets suspended in a proteinaceous fluid called Plasma.
If blood is treated to prevent clotting and permitted to stand in a container, the Red Blood Cells, weighing the most, will settle to the bottom; the Plasma will stay on top; and the White Blood Cells and Platelets will remain suspended between the Plasma and the Red Blood Cells. A centrifuge may be used to hasten this separation process. The platelet-rich plasma is then removed and placed into a sterile bag, and it can be used to prepare Platelets and Plasma or Cryoprecipitated AHF. To make Platelets, the platelet-rich plasma is centrifuged, causing the Platelets to settle at the bottom of the bag. Plasma and Platelets are then separated and made available for transfusion. The Plasma may also be pooled with Plasma from other donors and further processed, or fractionated, to provide purified Plasma proteins such as albumin, immunoglobulin and clotting factors.
Red Blood Cells are perhaps the most recognizable component of Whole Blood. Red Blood Cells contain hemoglobin, a complex iron-containing protein that carries oxygen throughout the body and gives blood its red color. The percentage of blood volume composed of Red Blood Cells is called the “hematocrit.” The average hematocrit in an adult male is 47 percent. There are about one billion Red Blood Cells in two to three drops of blood, and, for every 600 Red Blood Cells, there are about 40 Platelets and one white cell. Manufactured in the bone marrow, Red Blood Cells are continuously being produced and broken down. They live for approximately 120 days in the circulatory system and are eventually removed by the spleen.
Red Blood Cells are prepared from Whole Blood by removing the Plasma, or the liquid portion of the blood, and can raise the patient's hematocrit and hemoglobin levels while minimizing an increase in blood volume.
Patients who benefit most from transfusions of Red Blood Cells include those with chronic anemia resulting from disorders such as kidney failure, malignancies, or gastrointestinal bleeding and those with acute blood loss resulting from trauma or surgery. Since Red Blood Cells have reduced amounts of Plasma, they are well-suited for treating anemia patients who would not tolerate the increased volume provided by whole blood, such as patients with congestive heart failure or those who are elderly or debilitated. Red Blood Cells may be treated and frozen for extended storage (up to 10 years).
Plasma is the liquid portion of the blood--a protein-salt solution in which red and White Blood Cells and Platelets are suspended. Plasma, which is 90 percent water, constitutes about 55 percent of blood volume. Plasma contains albumin (the chief protein constituent), fibrinogen (responsible, in part, for the clotting of blood), globulins (including antibodies) and other clotting proteins. Plasma serves a variety of functions, from maintaining a satisfactory blood pressure and volume to supplying critical proteins for blood clotting and immunity. It also serves as the medium of exchange for vital minerals such as sodium and potassium, thus helping maintain a proper balance in the body, which is critical to cell function. Plasma is obtained by separating the liquid portion of blood from the cells.
Fresh Frozen Plasma is frozen within hours after donation to preserve clotting factors, stored for one to seven years, and thawed before it is transfused. It is most often used to treat certain bleeding disorders when a clotting factor or multiple factors are deficient and no factor-specific concentrate is available. It can also be used for Plasma replacement via a process called plasma exchange.
Cryoprecipitated AHF is the portion of Plasma that is rich in certain clotting factors, including Factor VIII, fibrinogen, von Willebrand factor and Factor XIII. Cryoprecipitated AHF is removed from Plasma by freezing and then slowly thawing the Plasma. It is used to prevent or control bleeding in individuals with hemophilia and von Willebrand’s disease, which are common, inherited major coagulation abnormalities. Its use in these conditions is reserved for times when viral-inactivated concentrates containing Factor VIII and von Willebrand factor are unavailable and Plasma components must be used.
Platelets (or thrombocytes) are very small cellular components of blood that help the clotting process by sticking to the lining of blood vessels. Platelets are made in the bone marrow and survive in the circulatory system for an average of 9-10 days before being removed from the body by the spleen. The Platelet is vital to life, because it helps prevent both massive blood loss resulting from trauma and blood vessel leakage that would otherwise occur in the course of normal, day-to-day activity. Units of Platelets are prepared by using a centrifuge to separate the platelet-rich Plasma from the donated unit of Whole Blood. The Platelet-rich Plasma is then centrifuged again to concentrate the Platelets further.
Platelets may also be obtained from a donor by a process known as apheresis, or plateletpheresis. In this process, blood is drawn from the donor into an apheresis instrument, which, using centrifugation, separates the blood into its components, retains the Platelets, and returns the remainder of the blood to the donor. The resulting component contains about six times as many Platelets as a unit of Platelets obtained from Whole Blood. Platelets are used to treat a condition called thrombocytopenia, in which there is a shortage of Platelets
1628 English physician William Harvey discovers the circulation of blood. Shortly afterward, the earliest known blood transfusion is attempted.
1665 The first recorded successful blood transfusion occurs in England: Physician Richard Lower keeps dogs alive by transfusion of blood from other dogs.
1667 Jean-Baptiste Denis in France and Richard Lower in England separately report successful transfusions from lambs to humans. Within 10 years, transfusing the blood of animals to humans becomes prohibited by law because of reactions.
1795 In Philadelphia an American physician, Philip Syng Physick, performs the first human blood transfusion, although he does not publish this information.
1818 James Blundell, a British obstetrician, performs the first successful transfusion of human blood to a patient for the treatment of postpartum hemorrhage. Using the patient's husband as a donor, he extracts approximately four ounces of blood from the husband's arm and, using a syringe, successfully transfuses the wife. Between 1825 and 1830, he performs 10 transfusions, five of which prove beneficial to his patients, and publishes these results. He also devises various instruments for performing transfusions and proposed rational indications.
1840 At St. George's School in London, Samuel Armstrong Lane, aided by consultant Dr. Blundell, performs the first successful whole blood transfusion to treat hemophilia.
1867 English surgeon Joseph Lister uses antiseptics to control infection during transfusions.
1873-1880 US physicians transfused milk (from cows, goats and humans).
1884 Saline infusion replaces milk as a “blood substitute” due to the increased frequency of adverse reactions to milk.
1900 Karl Landsteiner, an Austrian physician, discovers the first three human blood groups, A, B and O. The fourth, AB, is added by his colleagues A. Decastello and A. Sturli in 1902. Landsteiner receives the Nobel Prize for Medicine for this discovery in 1930.
1907 Hektoen suggests that the safety of transfusion might be improved by crossmatching blood between donors and patients to exclude incompatible mixtures. Reuben Ottenberg performs the first blood transfusion using blood typing and crossmatching in New York. Ottenberg also observed the mendelian inheritance of blood groups and recognized the “universal” utility of group O donors.
1908 French surgeon Alexis Carrel devises a way to prevent clotting by sewing the vein of the recipient directly to the artery of the donor. This vein-to-vein or direct method, known as anastomosis, is practiced by a number of physicians, among them J.B. Murphy in Chicago and George Crile in Cleveland. The procedure, however, proves unfeasible for blood transfusions, but paves the way for successful organ transplantation, for which Carrel receives the Nobel Prize in 1912.
1908 Moreschi describes the antiglobulin reaction.
1912 Roger Lee, a visiting physician at the Massachusetts General Hospital, along with Paul Dudley White, develops the Lee-White clotting time. Adding another important discovery to the growing body of knowledge of transfusion medicine, Lee demonstrates that it is safe to give group O blood to patients of any blood group, and that blood from all groups can be given to group AB patients. The terms "universal donor" and "universal recipient" are coined.
1914 Long-term anticoagulants, among them sodium citrate, are developed, allowing longer preservation of blood.
1915 At Mt. Sinai Hospital in New York, Richard Lewisohn uses sodium citrate as an anticoagulant to transform the transfusion procedure from direct to indirect. In addition, R. Weil demonstrates the feasibility of refrigerated storage of such anticoagulated blood. Although this is a great advance in transfusion medicine, it takes 10 years for sodium citrate use to be accepted.
1916 Francis Rous and J.R. Turner introduce a citrate-glucose solution that permits storage of blood for several days after collection. Allowing for blood to be stored in containers for later transfusion aids the transition from the vein-to-vein method to direct transfusion. This discovery also allows for the establishment of the first blood depot by the British during World War I. Oswald Robertson is credited as the creator of the blood depots.
1927-1947 The MNSs and P systems are discovered.
1932 The first blood bank is established in a Leningrad hospital.
1937 Bernard Fantus, director of therapeutics at the Cook County Hospital in Chicago, establishes the first hospital blood bank. In creating a hospital laboratory that can preserve and store donor blood, Fantus originates the term "blood bank." Within a few years, hospital and community blood banks begin to be established across the United States. Some of the earliest are in San Francisco, New York, Miami and Cincinnati.
1939/40 The Rh blood group system is discovered by Karl Landsteiner, Alex Wiener, Philip Levine and R.E. Stetson and is soon recognized as the cause of the majority of transfusion reactions. Identification of the Rh factor takes its place next to ABO as one of the most important breakthroughs in the field of blood banking.
1940 Edwin Cohn, a professor of biological chemistry at Harvard Medical School, develops cold ethanol fractionation, the process of breaking down plasma into components and products. Albumin, a protein with powerful osmotic properties, plus gamma globulin and fibrinogen are isolated and become available for clinical use. The efficacy of albumin in transfusion is demonstrated by John Elliott.
1940 The United States government established a nationwide program for the collection of blood. Charles R. Drew develops the “Plasma for Britain” program. The American Red Cross participates, collecting 13 million units of blood by the end of World War II.
1941 Isodor Ravdin, a prominent surgeon from Philadelphia, effectively treats victims of the Pearl Harbor attack with Cohn's albumin for shock. Injected into the blood stream, albumin absorbs liquid from surrounding tissues, preventing blood vessels from collapsing, a finding associated with shock.
1943 The introduction by J.F. Loutit and Patrick L. Mollison of acid citrate dextrose (ACD) solution, which reduces the volume of anticoagulant, permits transfusions of greater volumes of blood and permits longer term storage.
1943 P. Beeson publishes the classic description of transfusion-transmitted hepatitis.
1945 Coombs, Mourant and Race describe the use of antihuman globulin (later known as the “Coombs Test”) to identify “incomplete” antibodies.
1947 The American Association of Blood Banks (AABB) is formed to promote common goals among blood banking practitioners and the blood donating public.
1949-1950 The US blood collection system includes 1500 hospital blood banks, 46 community blood centers and 31 American Red Cross regional blood centers.
1950 Audrey Smith reports the use of glycerol cryoprotectant for freezing Red Blood Cells.
1950 In one of the single most influential technical developments in blood banking, Carl Walter and W.P. Murphy, Jr., introduce the plastic bag for blood collection. Replacing breakable glass bottles with durable plastic bags allows for the evolution of a collection system capable of safe and easy preparation of multiple blood components from a single unit of whole blood. Development of the refrigerated centrifuge in 1953 further expedites blood component therapy.
1951 The AABB Clearinghouse is established, providing a centralized system for exchanging blood among blood banks. Today, the Clearinghouse is called the National Blood Exchange.
Mid-1950s In response to the heightened demand created by open heart surgery and advances in trauma care patients, blood use enters its most explosive growth period.
1957 The AABB forms its committee on Inspection and Accreditation to monitor the implementation of standards for blood banking.
1958 The AABB publishes its first edition of Standards for a Blood Transfusion Service (now titled Standards for Blood Banks and Transfusion Services).
1959 Max Perutz of Cambridge University deciphers the molecular structure of hemoglobin, the molecule that transports oxygen and gives Red Blood Cells their color.
1960 The AABB begins publication of TRANSFUSION, the first American journal wholly devoted to the science of blood banking and transfusion technology. In this same year, A. Solomon and J.L. Fahey report the first therapeutic plasmapheresis procedure.
1961 The role of platelet concentrates in reducing mortality from hemorrhage in cancer patients is recognized.
1962 The first antihemophilic factor (AHF) concentrate to treat coagulation disorders in hemophilia patients is developed through fractionation.
1962 In the US, there were 4400 hospital blood banks, 123 community blood centers and 55 American Red Cross blood centers, collecting a total of five to six million units of blood per year.
1964 Plasmapheresis is introduced as a means of collecting Plasma for fractionation.
1965 Judith G. Pool and Angela E. Shannon report a method for producing Cryoprecipitated AHF for treatment of hemophilia.
1967 Rh immune globulin is commercially introduced to prevent Rh disease in the newborns of Rh-negative women.
1969 S. Murphy and F. Gardner demonstrate the feasibility of storing Platelets at room temperature, revolutionizing platelet transfusion therapy.
1970 Blood banks move toward an all-volunteer blood donor system.
1971 Hepatitis B surface antigen (HBsAg) testing of donated blood begins.
1972 Apheresis is used to extract one cellular component, returning the rest of the blood to the donor.
1979 A new anticoagulant preservative, CPDA-1, extends the shelf life of Whole Blood and Red Blood Cells to 35 days, increasing the blood supply and facilitating resource sharing among blood banks.
Early 1980s With the growth of component therapy, products for coagulation disorders and plasma exchange for the treatment of autoimmune disorders, hospital and community blood banks enter the era of transfusion medicine, in which doctors trained specifically in blood transfusion actively participate in patient care.
1983 Additive solutions extend the shelf life of Red Blood Cells to 42 days.
1985 The first blood screening test to detect HIV is licensed and quickly implemented by blood banks to protect the blood supply.
1987 Two tests for screening for indirect evidence of hepatitis C are developed and implemented, hepatitis B core antibody (anti-HBc) and the alanine aminotransferase test (ALT).
1989 Human T Lymphotropic Virus I antibody (anti-HTLV-I) testing of donated blood begins.
1990 Introduction of first specific test for hepatitis C, the major cause of “non-A, non-B” hepatitis, although the hepatitis C virus (HCV) has never been isolated.
1992 Testing of donor blood for HIV-1 and HIV-2 antibodies (anti-HIV-1 and anti-HIV-2) is implemented.
1996 HIV p24 antigen testing of donated blood begins. Although the test does not completely close the HIV window, it shortens the window period.
1997 US Government issues two reports suggesting ways to improve blood safety, including regulatory reform.
1998HCV lookback campaign begins.
1999 Blood community begins implementation of Nucleic Acid Amplification Testing (NAT) under the FDA’s Investigational New Drug (IND) application process. NAT employs a testing technology that directly detects the genetic materials of viruses like HCV and HIV.
