Technical Manual of Blood Components Preparation Bibekananda Mukherjee
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IntroductionChapter 1

In this world there is still no alternative of human blood. Scientist still cannot succeed in preparing synthetic blood or artificial blood. The amount of blood in a human body varies, depending on factors such as age, sex, overall health and even where a person lives. Scientists estimate the volume of blood in human body to be approximately 7% of body weight. An average person has 5–6 liters of blood in the body. Blood is the fluid circulating the heart, arteries, capillaries, and veins; carrying nutrients and oxygen to body cells, and removing waste products and carbon dioxide. So human beings are to be treated by only human blood. Today human blood is transfused in several ways and acts as medicine for treating a number of diseases. Components in a unit of whole blood include red blood cells, white blood cells, plasma, and platelets. Human blood consists of 55% plasma, 45% RBC, 0.1% WBC, and 0.17% platelets (See Fig. 2.1).
What is Better—Whole Blood or Components?
In our body there is 60–80 mL blood/kg of body weight. From this 16 mL is reserved. For donating of blood, the international prescribed standards says that a healthy person donates 8 mL/kg body weight of blood. Blood bags are available only in 350 mL and 450 mL size. So a 2person whose weight is above 45 kg can donate only 350 mL of blood, when the person whose weight is above 55 kg can donate 450 mL of blood. Whole blood is commonly obtained through blood donation and can be transfused directly or broken down into blood components that can be transfused separately.
Two methods are applied for preparation of components. One is the apheresis methodology, where a particular component is harvested from the donor by an automated machine. And another is whole blood collected from a healthy donor by aseptic means. Each whole blood is then processed to prepare various components.
With the availability of blood component preparation methodology now more than one patient is benefited from a unit of whole blood. For example the packed red blood cell can be transfused to thalassemia patients and the plasma and platelet can be issued to patients suffering from coagulopathy and dengue respectively. For thrombocytopenia cases platelets concentrate is more beneficial. Such patient should always receive a complete hemostatic dose of platelet which may comprise of 4–6 units platelet concentrates as per body weight. Blood banking involves collection, preparation, storage, and issue of blood and blood components after compatibility testing.