The average adult body contains between 4.7 and 5.2 litres of blood. If a lot of blood is lost, it must be replaced or the patient will die. Transfusions were not a common procedure until the 1900s. Attempts had been made as far back as the 1600s, but blood transfusion was not always safe and many people died in experiments to transfuse blood from patient to patient or animals to humans.
It was only when the Austrian medical scientist Karl Landsteiner developed techniques to identify blood types in 1909 that blood transfusion could be conducted with a degree of safety. Further experiments by Landsteiner discovered the ‘rhesus factor’, in which blood is identified as positive or negative.
By 1910, with sodium citrate as an anticoagulant, blood could be refrigerated and stored. During the First World War (1914-18), Geoffrey Keynes, a British surgeon, worked to develop a portable machine that could store blood to enable transfusions to be carried out more easily. It is thought that the first blood transfusion on the battlefield was performed in 1818 by the Prussians (Germans) directly from one patient to another.
By the 1930s blood plasma and red blood cells could be separated and could be stored for longer. Blood types - the rhesus blood-group system - were identified around 1939-40. By the Second World War new techniques of refrigeration and plasma storage meant that blood banks could be established and blood was available for any patient who needed it.
Blood banks are now a standard part of medical practice. However, there are differences in their organisation. Some countries only take donations from volunteers, while others pay people for their blood. Although blood transfusion can be a life-saving procedure, without proper screening diseases can unfortunately be passed from the donor to the recipient.
BibliographyZ Cope (ed.) History of the Second World War: Surgery (London: HMSO, 1953)
M Harrison, Medicine and Victory: British Military Medicine in the Second World War (Oxford: OUP, 2004)
K Pelis, ‘Transfusion, with teeth’ in R Bud, B Finn and H Trischler (eds) Manifesting Medicine: Bodies and Machines, R (Amsterdam: Harwood, 1999), pp 1-29
D Starr, Blood: An Epic History of Medicine and Commerce (New York: Alfred A Knopf, 1998)
The liquid component of blood, in which the blood cells are suspended. Plasma makes up around 55 per cent of blood's total volume.