Blood and blood substitutes.

Each year, in Europe, approximately seven million units of colloidal plasma substitutes are given to patients. Often they are used uncritically, which may account for the increased incidence of sideeffects which has been noted over the last decade. Their increasing use is understandable in view of the disadvantages of using blood; these include the difficulties in finding sufficient donors of all the blood groups, the problems of storage of blood and the inherent risks of blood transfusion which include the immunological and toxicological hazards. It should not be forgotten that there are advantages in replacing lost blood with whole blood or blood fractions. These include the similarity of the substitute to the lost fluid, the ability to bind, transport and deliver oxygen to the tissues and the ability to take over the various biochemical functions of the lost body fluids.