A bag of whole blood or a special method of drawing (apheresis) can be used in special processing procedures to prepare concentrated erythrocytes, concentrated platelets and fresh frozen plasma. Plasma can also be used to make blood-derived medicines, such as albumin, immunoglobulin, blood clotting factors and so on.
The transfusion of blood components is a therapy that is used to replace a patient's blood components.
Transfusion is justified and effective only when the recipient is provided with a component of safe blood that the patient in fact needs in therapy, i.e. in the amount and form that provides the best possible results. As a rule, transfusions are only used to replace a blood component that the patient lacks.
