Generality
Blood donation consists in taking a certain volume of blood from a healthy subject, called a donor, and then transferring it to another person, called a recipient, who needs blood or one of its components.
Before being able to donate blood, an individual must pass a series of careful checks and examinations, in order to assess the suitability of his state of health and the absence of any danger for the recipient.
Blood donation is a safe procedure, simple and almost completely free of side effects.
The blood, which is donated, is collected as such or, more often, separated into its main components.
What is blood donation?
Blood donation consists in collecting a certain volume of whole blood (about 450ml) from a healthy donor, and then transfusing it into a recipient subject in need of blood or its components ..
Blood donations are an essential part of a nation's health system, because, without the blood from voluntary donors, many therapeutic procedures could not take place and many lives could not be saved.
HOW MANY DONATIONS DO YOU GET IN ITALY EVERY YEAR?
According to the official website of the AVIS (Italian Volunteer Blood Associations), in Italy, in 2013, the voluntary donors, registered in this association, were 1, 298, 437, for a total of 2, 105, 934 donations made in 2013.
WHAT IS BLOOD COMPOSED OF?
The blood is formed by a set of cells, the haemocytes, and by a liquid part, called plasma.
The plasma constitutes 55% of the blood and is composed of water, mineral salts and colloidal proteins.
The haemocytes, which are suspended in the plasma, make up the remaining 45% of the blood and are represented by three different cellular elements:
- Red blood cells (or erythrocytes ) conduct oxygen to the tissues and organs of the body.
- White blood cells (or leukocytes ) are part of the immune system and defend the body from pathogens and from what can harm you.
- Platelets are among the main actors of coagulation.
Blood flows through our body into a complicated (but very precise) system of arterial (arterial) and venous (veins) vessels.
THE BLOOD GROUPS
Human blood is not all the same, but is characterized by some characteristics. These characteristics, which in fact correspond to the known blood groups, have been classified into systems. The most well-known and common systems are the AB0 system and the Rh system .
In light of this, the blood of each individual depends on the blood group and can be compatible, the same or totally different from that of another person.
Who can and cannot donate?
Anyone between the ages of 18 and 60, who weighs more than 50 kilograms, takes care of their lifestyle and is healthy and in good health can apply to become blood donors.
On the other hand, those who:
- They take drugs
- They are alcoholics
- They have sex at high risk of transmitting infectious diseases (for example, occasional, promiscuous relationships, etc.)
- Chronically they suffer from hepatitis or jaundice
- They suffer from a venereal disease
- They tested positive for the syphilis test
- They tested positive for the AIDS test ( HIV )
- Tested positive for hepatitis C ( anti-HCV )
- Tested positive for hepatitis B ( HBsAg )
- They have had sex with people suffering from one of the previous conditions
Summary table.
Basic conditions for applying to become a donor
- Age : minimum, 18 years; maximum, 60 years (this is the age bracket suitable for applying to become donors of whole blood, with exceptions to the doctor's judgment)
- Age up to which you can donate : 65 years (this is the maximum age to continue the donation activity for periodic donors, with exceptions to the doctor's judgment).
- Weight : more than 50 kilograms.
- Pulsations : between 50/100 beats per minute (NB: those who practice certain sports have an even lower heart rate; however, these individuals can still be donors).
- Arterial pressure : between 110 and 180 mm of mercury, the maximum (or systolic); between 60 and 100 mm of mercury, the minimum (or diastolic).
- State of health : the person must be healthy and in good, if not perfect, state of health.
- Lifestyle : healthy, that is no risk behavior.
THE BLOOD TESTS
For those who are candidates to become donors, a blood test and an accurate analysis of the latter is planned, in order to establish whether the volunteer is actually a healthy person and is not affected by one of the aforementioned pathological conditions.
But where do all the above checks take place?
There are special hospital facilities, called transfusion centers, in which all assessments and withdrawals are carried out, in order to become a donor. In Italy, the transfusion centers are around 340 (2012).
WHEN YOU MUST STOP THE DONOR ACTIVITY
In some situations, for the sake of those who require blood transfusions, it is necessary to self-suspend, temporarily, from the donor activity. For example, temporary self-suspension must be taken into consideration if in the last four months cosmetic operations have been carried out, such as tattoos, piercings, earrings; if in the days before or on the day of the donation, you suffer from a cold or another similar viral infection (for example, an influenza); if you are taking antibiotics; etc.
In light of this, it is quite clear the concept that giving blood is not just an act of generosity, but also requires a sense of responsibility and sensibility.
Below is a list of the most common situations that require temporary self-suspension.
We must suspend blood donations:
- When a serious surgical procedure has recently been carried out .
- When you have had a dental procedure . The self-suspension, in these cases, varies according to the type of operation: it can be only 24 hours, for a simple filling, or 7 days, for a dental extraction.
- When one has come into contact, for work or family reasons, with individuals suffering from more or less serious infectious diseases . For example, the medical and nursing staff in hospitals may have to treat AIDS or hepatitis C patients. Although there are all the necessary protections, it is good to wait some time before resuming donating blood, and possibly undergoing new to blood tests.
- When, over the twelve months preceding a donation, he suffered from jaundice or hepatitis A.
- When you are pregnant or have recently given birth (the interruption is valid for up to 6 months).
- When, in the days near the time of the donation, one was on antibiotic therapy .
- When, in the 4 months before a donation, people got vaccinated against some infectious disease.
- When, in the vicinity or on the day of the donation, one has suffered or suffers from a cold, sore throat, flu and other similar infectious diseases.
- When cosmetic operations such as tattoos, piercings and earrings have been performed in the last 4 months.
- When you recently visited (maximum 6 months) a country, where malaria is endemic (that is, typical of a particular territory).
- When you suffer from temporary anemia . Anemia, in fact, is not always a chronic disorder, but it can also be a temporary condition (for example, the anemic state of women with heavy menstruation).
For any further information regarding self-suspension, just contact the nearest blood transfusion center.
How it happens
NB: everything that will be read in the next lines, assumes that the individual, who wants to donate blood, has already been considered suitable for donation.
Blood donation is a very simple procedure, easy to perform and at very low risk, which lasts, overall, no more than an hour.
First of all, to donate blood, the donor must go to a blood transfusion center (possibly the one where the candidacy exams took place). Here, a doctor will ask you a series of questions, regarding your current and past health status, and several quick tests (blood pressure measurement, heart rate measurement, etc.) to make sure that no complications arise during or after the procedure .
If all this ends in a positive way (that is, there are no contraindications to the donation), we move on to the collection of real blood. The quantities extracted correspond to about 450 milliliters ± 10%.
After the withdrawal, it may be necessary to rest for a few hours, waiting for the possible fainting and stunning to disappear.
The blood collected by the transfusion center, before being used for therapeutic purposes, is carefully analyzed, to make sure of its goodness to protect the possible recipients.
PREPARATION FOR DONATION
At the time of donation, it is advisable to be fasting for a few hours or, if it is not possible to present yourself on an empty stomach, it is good to have taken a light meal, free of fat and sugar.
In general, the withdrawals take place in the morning, so the aforementioned recommendations can be followed easily: in fact, we have returned from the dinner the previous evening.
Attention : it is strictly forbidden to drink alcohol before donation. The only soft drinks granted are water, fruit juices with no added sugar, unsweetened tea or coffee.
CHECK-UP ON THE SPOT: QUESTIONNAIRE AND BLOOD CHECKS
If it is the first donation, when you reach the transfusion center, you will be informed about how the whole procedure will take place.
If, on the other hand, you are a regular donor, you immediately go to the next phase, that is the questionnaire and the checks, related to your health.
The questions are usually asked by a doctor, who wants to know essentially if the donor:
- He's fine and healthy.
- He has suffered from some disease in recent months. If so, which one.
- He underwent surgery, dentistry, cosmetics, etc.
- He has had, in recent months, occasional sexual relations or with a new partner.
The utmost honesty is obviously required.
The controls concern the measurement of blood pressure, heart rate and, finally, how much hemoglobin is contained in the blood (see next sub-chapter).
CHECK-UP FOR ANEMIA
Among the various pre-donation checks, there is one particular, which assesses the amount of hemoglobin contained in the donor's blood. Hemoglobin is the fundamental protein of red blood cells (or erythrocytes), which carries oxygen in the human body.
When the hemoglobin, present in the blood, is little or when the red blood cells, which contain it, are few, we speak of anemia or anemic state . Anemia can be chronic or temporary. Chronic anemia is usually a severe and stable condition, linked to a genetic mutation or a serious illness; temporary anemia, on the other hand, is a temporary condition, which can arise in some particular moments of a person's life.
The main symptoms of anemia:
- Fatigue
- Apathy
- Shortness of breath
- Palpitations
Why is the hemoglobin present in the donor's blood quantified before a blood donation?
In light of what has been said about the function and lack of hemoglobin, it can be assumed that taking blood from an individual with temporary anemia can further aggravate their state of health.
Therefore, a donor who appears to be anemic at the time of the donation must abstain from the latter and postpone it to another occasion. In the meantime, a consultation with your doctor is recommended, especially if you regularly suffer from temporary anemia.
The check-up for anemia takes place very quickly, thanks to a special tool, and requires the taking of a minimum amount of blood.
THE COLLECTION
Once it is established that the donor is healthy and healthy, and that there are no contraindications to the donation, we proceed to the withdrawal .
First of all, a rubber tie ( tourniquet ) is tied around an arm, which serves to swell and highlight the vein, from which the blood will be drawn.
At this point, the infusion line is, in turn, connected to a bag or a container: only after this operation, the aspiration of the blood begins.
The quantities of blood taken are about 450 milliliters ; this is not a large amount, considering that it is about 10% of the blood circulating in our body and that our body restores it within a few hours.
The withdrawal procedure alone takes 10-15 minutes, no more.
THE CHECKS ON THE DONATED BLOOD
The blood extracted from the donor, before it can be used for therapeutic purposes, must be analyzed carefully, for safety reasons.
Only once he has passed all the laboratory tests and has been found not contaminated by viruses and other pathogens (AIDS virus, hepatitis C, etc.), he is placed in so-called blood stores. A blood library is a refrigerator cabinet, built specifically to store blood bags.
THE FIRST FEELINGS AFTER THE DONATION
After the donation, it is likely that the donor feels faint or feels a slight feeling of lightheadedness. It is a normal consequence, for which you should not be alarmed, but only to rest, eat something and drink enough.
Warnings : smokers are advised not to smoke for at least a couple of hours, since the donation ended.
COLATERAL EFFECTS
Blood donation is a safe procedure. However, in some cases, it can lead to side effects of varying degrees.
- Appearance of a bruise in the skin area, where the removal occurred. It happens to one person every 4 or so.
- Sore arm . It happens in one case every 10 or so.
- Dizziness and fainting . It happens to a donor every 15 or so.
The appearance of complications more serious than those mentioned above is really very rare and occurs in a donor every 3, 500.
Uses of donated blood
Thanks to the blood collected by donors, so many human lives can be saved. The so-called blood transfusions, in fact, are foreseen in many surgical interventions and in the treatment of many blood diseases.
The blood can be used as it was collected (whole blood), or after having separated it into some of its components. It is, in fact, possible to use only the plasma, only the red blood cells or only the platelets, based on the cases that arise from time to time.
Today, unlike in the past, whole blood transfusion is very rare, as the transfusion of a single component is much more convenient and effective.
HOW DO THE SEVERAL BLOOD COMPONENTS SEPARATE?
The decomposition of the blood, in its liquid and cellular components, takes place by means of special separators, which work according to the principle of centrifugation .
Indeed, there is the possibility of taking, during a donation, only one blood component, returning all the others to the donor. This operation, called apheresis, is carried out in the following way: the blood is taken, as if it were a normal donation, but instead of storing it all in a bag, it is immediately passed through a separator. The desired component is retained and collected separately, what remains of the blood is returned to the donor.
Plasmapheresis is the separation of the plasma, or the liquid part of the blood, from the cellular components. Platelet apheresis is the separation of platelets from the plasma and the remaining cellular component. Erythro-apheresis is the separation of red blood cells from plasma and from what remains of other cells.
NB: there is also the leukapheresis, which is the separation of white blood cells from the rest of the blood components, but it is a very rare practice.
RED BLOOD CELLS
The storage and use of red blood cells alone is used to treat some forms of anemia, such as sickle cell anemia (or sickle cell disease), and in all those cases where an individual has lost large amounts of blood (for example, after a birth, a car accident, an organ transplant surgery, etc.).
Red blood cells contain oxygen, so their infusion serves to restore part of the lost oxygen quota.
Figure: a pocket of blood plasma only
PLASMA
Plasma contains many fundamental proteins (for example, albumin ), keeps the volume of circulating blood constant and carries nutrients, which feed the tissues and cells of the body.
It is used, very often, after a birth or after a heart surgery.
To be preserved, the plasma must be frozen: in this state, it can last up to 12 months.
PLATES
The platelets, thanks to their coagulant power, are administered when an individual suffers from bleeding, caused by damage to the bone marrow.
Bone marrow is a soft tissue that has the job of producing all the blood cells.
Platelet infusion is particularly suitable for patients with leukemia .
Other types of donation
Next to the described venous blood donation, there is another that goes to take the blood of the placenta of a mother or of the umbilical cord of a newborn, at the time of delivery.
What is the purpose of umbilical or placental blood donation?
Placenta and umbilical cord contain, in addition to the traditional blood elements (hemocytes and plasma), a certain amount of extraordinary cells, the so-called hematopoietic stem cells .
HEMATOPOIETIC STEM CELLS - THE COLLECTION
Hematopoietic stem cells, also called bone marrow cells, are the blood progenitor cells. They have the ability to continually replicate and choose whether to become red blood cells, white blood cells or platelets.
Thanks to their potential, they represent a possible treatment for blood diseases, such as leukemia and some diseases of the immune system, which are characterized by insufficient bone marrow activity.
The removal of umbilical or placental stem cells takes place immediately after a child is born. It requires parental consent, but it is not risky, neither for the mother nor for the newborn.
The procedure is very simple and consists of storing the umbilical cord and / or the placenta in a special cold room.
Frequent questions
Is blood donation dangerous?
Blood donation does not pose any risk to the donor. The whole procedure, in fact, takes place in absolute sterility and involves taking one's own blood.
How long should you spend between two whole blood donations?
At least 12 weeks for men and at least 16 for women. However, at times, no distinction is made between males and females and we talk about both sexes for 90 days.
How many blood donations can you make per year?
The annual frequency varies according to sex. The man must not exceed the 4 donations a year, while the woman in fertile age must not exceed 2 donations a year.
Is blood donation contraindicated for women?
No, there is no counter-indication, as long as the annual frequency is respected. In fact, more than two donations a year could cause iron and hemoglobin deficiencies (anemia). If a donor is subject to heavy menstruation, she can always resort to plasmapheresis.
Why is it important that there are so many donors?
The more blood donors there are, the more blood is available for therapeutic transfusions. However, it would be limiting to say that this is the only advantage. In fact, the possibility of counting on so many donors guarantees a greater availability of different blood, belonging also to rare blood groups.
Blood donation associations seek periodic donors. What does it mean?
Periodic blood donors are those who travel to or plan to donate blood at regular intervals. The blood donor is periodically a much more controlled and much more reliable individual than the occasional donor.
Blood donation associations seek and use regular donors to ensure a safe service and protect recipients.
