providing a donor, oliver set about organizing a system for the voluntary registration of blood donors at clinics around london, with sir geoffrey keynes appointed as a medical adviser. volunteers were subjected to a series of physical tests to establish their blood group. the london blood transfusion service was free of charge and expanded rapidly in its first few years of operation. by 1925 it was providing services for almost 500 patients; it was incorporated into the structure of the british red cross in 1926. similar systems developed in other cities, including sheffield, manchester and norwich, and the service's work began to attract international attention. france, germany, austria, belgium, australia and japan established similar services. alexander bogdanov founded an academic institution devoted to the science of blood transfusion in moscow in 1925. bogdanov was motivated, at least in part, by a search for eternal youth, and remarked with satisfaction on the improvement of his eyesight, suspension of balding, and other positive symptoms after receiving 11 transfusions of whole blood. bogdanov died in 1928 as a result of one of his experiments, when the blood of a student with malaria and tuberculosis was given to him in a transfusion. following bogdanov's lead, vladimir shamov and sergei yudin in the ussr pioneered the transfusion of cadaveric blood from recently deceased donors. yudin performed such a transfusion successfully for the first time on march 23, 1930, and reported his first seven clinical transfusions with cadaveric blood at the fourth congress of ukrainian surgeons at kharkiv in september. however, this method was never used widely, even in the soviet union. nevertheless, the soviet union was the first to establish a network of facilities to collect and store blood for use in transfusions at hospitals. british poster of 1944 encouraging people to donate blood for the war effort frederic durán-jordà established one of the earliest blood banks during the spanish civil war in 1936. duran joined the transfusion service at the barcelona hospital at the start of the conflict, but the hospital was soon overwhelmed by the demand for blood and the paucity of available donors. with support from the department of health of the spanish republican army, duran established a blood bank for the use of wounded soldiers and civilians. the 300–400 ml of extracted blood was mixed with 10% citrate solution in a modified duran erlenmeyer flask. the blood was stored in a sterile glass enclosed under pressure at 2 °c. during 30 months of work, the transfusion service of barcelona registered almost 30,000 donors, and processed 9,000 liters of blood. in 1937 bernard fantus, director of therapeutics at the cook county hospital in chicago, established the first hospital blood-bank in the united states. in setting up a hospital laboratory that preserved, refrigerated and stored donor blood, fantus originated the term "blood bank". within a few years, hospital and community blood-banks were established across the united states. frederic durán-jordà fled to britain in 1938 and worked with dr janet vaughan at the royal postgraduate medical school at hammersmith hospital to establish a system of national blood banks in london. with the outbreak of war appearing imminent in 1938, the war office created the army blood supply depot (absd) in bristol, headed by lionel whitby and in control of four large blood-depots around the country. british policy through the war was to supply military personnel with blood from centralized depots, in contrast to the approach taken by the americans and germans where troops at the front were bled to provide required blood. the british method proved more successful in adequately meeting all requirements, and over 700,000 donors were bled over the course of the war. this system evolved into the national blood transfusion service established in 1946, the first national service to be implemented. stories tell of nazis in eastern europe during world war ii using captive children as repeated involuntary blood-donors. medical advances wounded soldier being given blood plasma in sicily, 1943 a blood-collection program was initiated in the us in 1940 and edwin cohn pioneered the process of blood fractionation. he worked out the techniques for isolating the serum albumin fraction of blood plasma, which is essential for maintaining the osmotic pressure in the blood vessels, preventing their collapse. gordon r. ward, writing in the correspondence columns of the british medical journal, proposed the use of blood plasma as a substitute for whole blood and for transfusion purposes as early as 1918. at the onset of world war ii, liquid plasma was used in britain. a large project, known as "blood for britain", began in august 1940 to collect blood in new york city hospitals for the export of plasma to britain. a freeze-dried plasma package was developed by the surgeons general of the army and navy, working with the national research council, which reduced breakage and made transportation, packaging, and storage much simpler. charles r. drew oversaw the production of blood plasma for shipping to britain during ww2. the resulting dried plasma package came in two tin cans containing 400 ml bottles. one bottle contained enough distilled water to reconstitute the dried plasma contained within the other bottle. in about three minutes, the plasma would be ready to use and could stay fresh for around four hours. dr. charles r. drew was appointed medical supervisor, and he was able to transform the test-tube methods into the first successful technique for mass production. another important breakthrough came in 1937–40 when karl landsteiner (1868–1943), alex wiener, philip levine, and r.e. stetson discovered the rhesus blood group system, which was found to be the cause of the majority of transfusion reactions up to that time. three years later, the introduction by j.f. loutit and patrick l. mollison of acid–citrate–dextrose (acd) solution, which reduced the volume of anticoagulant, permitted transfusions of greater volumes of blood and allowed longer-term storage. carl walter and w.p. murphy jr. introduced the plastic bag for blood collection in 1950. replacing breakable glass bottles with durable plastic bags made from pvc allowed for the evolution of a collection system capable of safe and easy preparation of multiple blood components from a single unit of whole blood. in the field of cancer surgery, the replacement of massive blood-loss became a major problem. the cardiac-arrest rate was high. in 1963 c. paul boyan and william s. howland discovered that the temperature of the blood and the rate of infusion greatly affected survival rates, and introduced blood warming to surgery. further extending the shelf-life of stored blood up to 42 days was an anticoagulant preservative, cpda-1, introduced in 1979, which increased the blood supply and facilitated resource-sharing among blood banks. as of 2006 about 15 million units of blood products were transfused per year in the united states. by 2013 the number had declined to about 11 million units, because of the shift towards laparoscopic surgery and other surgical advances and studies that have shown that many transfusions were unnecessary. for example, the standard of care reduced the amount of blood transfused in one case from 750 to 200 ml. special populations neonate to ensure the safety of blood transfusion to pediatric patients, hospitals are taking additional precautions to avoid infection and prefer to use specially tested pediatric blood units that are guaranteed negative for cytomegalovirus. most guidelines recommend the provision of cmv-negative blood components and not simply leukoreduced components for newborns or low birthweight infants in whom the immune system is not fully developed. these specific requirements place additional restrictions on blood donors who can donate for neonatal use. neonatal transfusions typically fall into one of two categories: "top-up" transfusions, to replace losses due to investigational losses and correction of anemia. exchange (or partial exchange) transfusions are done for removal of bilirubin, removal of antibodies and replacement of red cells (e.g., for anemia secondary to thalassemias and other hemoglobinopathies). significant blood loss a massive transfusion protocol is used when significant blood loss is present such as in major trauma, when more than ten units of blood are needed. packed red blood cells, fresh frozen plasma, and platelets are generally administered. typically higher ratios of fresh frozen plasma and platelets are given relative to packed red blood cells. unknown blood type because blood type o negative is compatible with anyone, it is often overused and in short supply. according to the association for the advancement of blood and biotherapies, the use of this blood should be restricted to persons with o negative blood, as nothing else is compatible with them, and women who might be pregnant and for whom it would be impossible to do blood group testing before giving them emergency treatment. whenever possible, the aabb recommends that o negative blood be conserved by using blood type testing to identify a less scarce alternative. religious objections jehovah's witnesses may object to blood transfusions because of their belief that blood is sacred. research into alternatives