(b) Red Cells: carry oxygen from lungs to various body tissues and take back carbon dioxide from the cells and tissues to be thrown out of body in the form of exhaled air.
(c) White cells: mainly act as body scavengers and guards. They help in the immune system of the body and act as defence forces of the body killing the bacteria or any other organisms entering the body.
(d) Platelets: help in the clotting and coagulation of blood. We have experienced in our life that whenever we get injured the bleeding stops after a few minutes. This is brought about by a mechanism called clotting of blood in which platelets plays a very vital role.
Red blood cells have a life of 120 days and when it becomes old and senile it is thrown out. White cells live for a few days and platelets for a few hours. Thus daily new cells are added to the circulation and old are removed from it.
In the ABO group there are four categories namely A Group, B Group, O Group and AB Group.
In the Rh Group either the individual is Rhpositive, or Rhnegative. Rh is a factor called as Rhesus factor that has come to us from Rhesus monkeys.
Thus each and very human being will
fall in one of the following groups.
A positive or A negative
B positive or B negative
O positive or O negative
AB positive or AB negative
There are also some sub groups as
well as a few other classifications.
In cases where a woman has Rh negative and her husband has Rh positive, the first child with Rh positive may be normal. But subsequently the woman may not conceive or may have repeated abortions. There may be intra uterine fetal death. If the child born is alive, it will suffer from a fatal disease called "Erythroblastosis Foetalis". Now mothers can be given an injection of antiD within 24 hours of the delivery of a Rhpositive child and thus protect the next baby from this catastrophe.
In most progressive blood banks more than 85 % of the blood collected is converted into components and stored. This is because many patients do not require whole blood. For example, a patient whose hemoglobin is low and is therefore anemic, may just require Packed Cells i.e. only red cells; a patient with burns may need more of plasma than cells; a patient with hemophilia may require only Factor VIII.
Now with the advent of Cellseparators we can directly draw a particular component from the donor, while rest of the blood constituents go back to the donor.
1. Patient complains of shivering, restlessness, nausea, and vomiting. There is precardial and lumbar pain.
2. Cold, clammy skin with cyanosis.
3. Pulse rate increases, respiratory rate increases. Temperature increases to 38 to 40 deg C. [101 to 105 F].
4. Blood pressure falls and patient passes into a state of shock.
5. Haemoglobinaemia, haemoglobinurea (urine turns red); oliguria (urine becomes scanty or the urinary output is reduced) and anuria (total output of urine becomes 200 ml. a day)
6. Jaundice appears after a few hours and in some cases anuria persists and uremia develops. This may lead to death.
(1) PROFESSIONAL DONORS They sell their blood, which is of very poor quality and can transmit very dangerous diseases to the recipient. It is illegal to take blood from any professional donor.
(2) REPLACEMENT DONATION Healthy relatives and friends of the patient give their blood, of any group, to the blood bank. In exchange, the required number of units in the required blood group is given.
(3) VOLUNTARY DONATION Here a donor donates blood voluntarily. The blood can be used for any patient even without divulging the identity of the donor. This is the best type of blood donation where a motivated human being gives blood in an act of selfless service.
Fever: He should not have suffered from fever for the past 15 days.
Jaundice: A donor should not have his blood tested positive for AUSTRALIA ANTIGEN.
Blood transmitted diseases: Like Syphilis, Malaria, Filaria etc. debar a donor from donating blood till he is treated and is free from them.
Drugs: If a donor is taking drugs like Aspirin, antihypertensive, antidiabetics, hormones, corticosteroids etc., he is unfit to donate blood.
AIDS. No person having HIV positive can be allowed to donate blood.