Blood Supply

Not all of the collected blood is used as whole-blood transfusions. Some of the supply is broken down into its components. Blood plasma, the liquid part of blood that remains once the blood has coagulated (clotted), can be dried into a powder and used as a replacement for blood volume lost from wounds. Blood plasma need not be refrigerated so it is useful in situations such as battlefields and areas that lack proper refrigeration. The plasma powder is reconstituted by mixing it with sterile water. It is then infused into the wounded or injured patient.

Thousands of units of blood can be combined and the clotting factor (Factor VIII) refined from the mixture. Factor VIII is used by hemophiliacs to provide the ingredient they lack to make their blood clot. Without the clotting factor a hemophiliac can bleed uncontrollably.

Blood cells also can be separated and used. Concentrated red blood cells can improve the blood count of an anemic patient. White blood cells and platelets also are isolated and transfused into needy patients.