1. What is Blood? How much blood does a person have?
2. What is the composition of Blood?
3. What are the functions of these components?
4. Can we separate blood into its components?
5. What is Haemoglobin?
6. What are blood groups?
7. What is the importance of knowing the Blood Groups?
8. Why are Rh negative and Rh positive incompatible?
9. What happens to patients in transfusions with incompatible Blood?
1. Who is a Donor?
2. How long does the donation take?
3. Does the donor need to do anything special before donating blood?
4. Does the donor suffer from any harmful effects after donating blood?
5. Does the donor need to rest after donating blood?
6. Can a donor work after donating blood?
7. What special diet should a donor follow after giving blood?
8. How frequently can a donor donate blood?
9. How long will it take for the body to replenish the donated blood?
10. Do any diseases debar a donor from giving blood?
11. What are the diseases which can be transferred through blood?
Q. What is Blood? How much blood does a person have?
A. Blood is the red coloured fluid flowing continuously in our body’s circulatory system. The donated blood includes whole human blood drawn from a donor and mixed with anticoagulant (to prevent clotting of blood). Adult male has about 76 ml blood / Kg and female has 66 ml/kg
Q. What is the composition of Blood?
A. Blood contains mainly a fluid called plasma in which are suspended cellular elements. Three types of cells - Red Blood Cells (RBC’s), White Blood Cells (WBC’s) and tiny platelets form the cellular elements.
Q. What are the functions of these components?
A. a) Plasma: acts as a vehicle to carry many substances like glucose, fats, and proteins, enzymes, and hormones etc., in addition to the blood cells.
(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 defense 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.
Q. Can we separate blood into its components?
A. Yes! Now with technical advancements, we can make components of blood and store them. For example, plasma can be separated from whole blood and stored up to one year in frozen state at -80 deg C temperature or below. This is called Fresh Frozen Plasma. Similarly there are other components like Packed Red Blood Cells (stored at 4 degree C for 35 days in CPDA & for 42 days in Adsol/SAGM additive solution); Platelet Concentrate (can be stored as a life saving measure upto 5 days now at 22- 24 degrees C in a platelet incubator and agitator); Cryoprecipitate (which is very useful in treating bleeding disorders due to the deficiency of factor VIII and IX); Factor VIII and IX; Albumin, Globulin and many others.
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 Cell-separators we can directly draw a particular component from the donor, while rest of the blood constituents go back to the donor.
Q. What is Haemoglobin?
A. Haemoglobin is a substance present in the red cells. It is helpful in carrying oxygen and carbon dioxide. On an average, in a healthy male it should be between 14 - 16 gm % and in a female it should be about 12 - 14 gm %. This is also being daily synthesized and the new is replacing the old stock.
Q. What are blood groups?
A. Every individual has two types of blood groups. The first is called the ABO - grouping and the second type is called Rh - grouping.
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 Rh-positive, or Rh-negative. 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.
Q. What is the importance of knowing the Blood Groups?
A. For all practical and routine purposes, it is ideal to transfuse to the patient the same group of blood which he belongs to. It is only under very dire emergency that we take O group as universal donor and AB groups as universal recipient. Under no circumstances O group can get any other blood except O. Similarly A group patient cannot be given B group blood and vice versa.
Q. Why are Rh negative and Rh positive incompatible?
A. A patient with Rh-negative blood cannot be given Rh-positive blood as the antigen-antibody REACTIONS WILL RESULT IN SEVERE consequences.
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 anti-D within 24 hours of the delivery of a Rh-positive child and thus protect the next baby from this catastrophe.
Q. What happens to patients in transfusions with incompatible Blood?
A. The following symptoms may occur after only a few ml. of blood have been given:
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.
Q. Who is a Donor?
A. Donor is a person who voluntarily donates blood after he/she has been declared fit after a medical examination for donating blood, on fulfilling the criteria given herein after; without accepting in return any consideration in cash or kind from any source, but does not include ‘professional’ or ‘paid’ donor.
Q: Does a donor need to do anything special before donation?
A: The donor should eat at regular mealtimes and drink plenty of fluids.
Q: How long does the donation take?
A: The procedure is done by skilled, specially trained technicians and takes three to eight minutes. However, from start to finish (filling form, post donation rest etc) the entire process should take upwards of 25-30 minutes.
Q: Does the donor suffer from any harmful effects after donating blood donation?
A: Absolutely not, rather a donor after having given blood voluntarily gets a feeling of great pleasure, peace and bliss. Soon, within a period of 24 - 48 hours, the same amount of new blood gets formed in the body, which helps the donor in many ways. His own body resistance improves, the circulation improves, and he himself feels healthier than before.
Q: Does a donor need to rest after donating blood?
A: Yes. The donor needs rest, preferably lying down, so that the amount of blood that has been donated soon gets poured into the circulation from the body pools in a natural way. The donor should take it easy for about 15 - 20 minutes.
Q: Can a donor work after donating blood?
A: Of course! Routine work is absolutely fine after the initial rest. Rigorous physical work should be avoided for a few hours.
Q: What special diet should a donor follow after giving blood?
A: After resting for a while a donor is given some liquid (fluid) to take. It may be a cup of coffee or milk or fruit juice alongwith a few biscuits or fruit. The donor needs no other special diet. A routine balanced diet is adequate. The donor's blood gets replenished within 24 - 48 hours.
Q: How long will it take for the body to replenish the blood?
A: The body replaces blood volume or plasma within 24 hours. Red cells need about four to eight weeks for complete replacement.
Q: How frequently a donor can donate blood?
A: Three months time between donations is a very safe interval.
Q: Do any diseases debar a donor from giving blood?
A: Yes, if the donor has suffered from any of the under-mentioned diseases: -
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, anti-hypertensive, anti-diabetics (Insulin), hormones, corticosteroids etc., he is unfit to donate blood.
AIDS. No person having HIV positive can be allowed to donate blood
12. What are the diseases which can be transferred through blood?
b. Hepatitis B &C
c. EBV - Ebstein Barrr Virus