Transfusion consists of the infusion of blood or some of its components (or one of the products that are obtained from the separation of whole blood) to meet specific clinical needs. It involves measurable risks and involves the use of a limited resource such as blood (which cannot be artificially produced in the laboratory). Also for this reason it must be used according to precise indications and using the specific blood component for the defect to be corrected.
The blood components that derive from the fractionation of donated blood are divided into:
- Red blood cells (for the treatment of anemia)
- platelets (for the treatment of platelet disorders)
- plasma (for the treatment of coagulation disorders)
There transfusion of red blood cells its primary indication is to re-establish, or maintain, the transport of oxygen from the lungs to the tissues. This function is performed by hemoglobin, a protein which is the main constituent of red blood cells.
In some specific situations resulting from anemia, a transfusion of red blood cells can be performed to increase the hemoglobin value and, therefore, the available oxygen. It is a very common type of transfusion and is often a life-saving therapy in some conditions such as:
- traumatic events, accidents or surgery
- chronic anemias such as thalassemia or sickle cell anemia or other forms present at birth (congenital) of red blood cell membrane defect
- tumor or onco-haematological diseases (leukemia, lymphomas etc)
- severe anemia related to some types of therapies (for example, chemotherapies)
- severe anemias that cannot be treated with iron, folate or vitamin B (hematinic)
There transfusion of platelets it can be used:
- for preventive purposes, to avoid bleeding episodes
- for therapeutic purposes, to stop bleeding in areas where there is bleeding
There plasma transfusion finds its main indication in the correction of selective deficiencies of coagulation factors for which there is no specific replacement therapy or in the case of a deficiency of several coagulation factors in patients with ongoing bleeding. Other indications are:
- severe liver disease with coagulation disturbances (INR ≥ 2) and ongoing bleeding
- therapy of some diseases, such as thrombotic microangiopathies (e.g. thrombotic purpura, thrombocytopenia, uraemic-haemolytic syndrome)
- replacement of the patient's blood with that of a donor through continuous transfusions (reconstitution of whole blood for exsanguino-transfusion)
- hereditary angioedema due to the lack of a component involved in immune reactions (the activator of C1 esterase), in the absence of a specific replacement therapy
Before undergoing transfusion therapy, the patient must always be correctly and completely informed of the possible alternatives to transfusion (if any), of the benefits deriving from it, of its potential undesirable effects (side effects) and also of the possible consequences in case of refusal to undergo such treatment. The expression of consent to undergo transfusion therapy must always require the patient to sign the information document (informed consent).
Blood transfusion consists in intravenously infusing a person (called the recipient) with red blood cells, plasma or platelets taken from an individual who voluntarily donated blood (donor).
During the transfusion, a small needle is inserted into a vein of the person receiving the transfusion, to allow the component (blood component) contained in the bag (unit) to enter the bloodstream. The duration of the transfusion depends on the type of blood component transfused; generally, in the first 15 minutes the infusion rate should be 10-20 drops per minute. Subsequently, if no disturbances (symptoms) have appeared that indicate a reaction to the transfusion, the infusion rate can be increased in the judgment of the physician and consistent with the patient's condition.
On each bag (unit) of blood component assigned is applied a "label (assignment label) containing the certificate of compatibility, the identification data of the blood component and those of the person who will receive the transfusion. The identification of the person to be transfused. (recipient) must be performed by two healthcare professionals immediately prior to the initiation of the transfusion. It requires the collaboration of the patient, if his conditions allow it, and requires the request of his personal details (name, surname and date of birth), the verification that the data shown on his identification bracelet correspond to those present on each single unit to be transfused .
Most transfusions are done without problems for the recipient. Only in rare cases can more or less serious reactions occur (haemolytic, febrile, allergic reactions, etc.).
A different type of possible complications that could occur is represented by the transmission of infectious agents (HIV, hepatitis B virus, hepatitis C virus, syphilis).In this regard, it should be noted that in Italy the degree of safety of blood components with respect to the risk of transmission of known infectious agents (HIV, hepatitis B virus, hepatitis C virus and syphilis) has reached extremely high levels for many years. high. This level of safety is guaranteed by a system based on voluntary, periodic, anonymous, responsible and unpaid donation, by the use of highly sensitive laboratory tests and by an accurate medical selection of blood donors, which provides for the exclusion of people who, for clinical or behavioral reasons, may be considered at risk.
In Italy, according to the legislation in force, each blood unit donated must be tested for hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV) and Treponema pallidum (syphilis). Only the blood units tested negative to the above tests can be used for transfusion purposes (read the Bufala).
The risk of contracting an "infection following a blood transfusion, therefore, is close to zero. In the face of more than 3 million blood components transfused every year (8,349 blood components transfused every day), for over ten years in Italy they have not Post-transfusional infections with HIV, hepatitis B virus and hepatitis C virus have been reported.
Ministry of Health. Decree 2 November 2015. Provisions relating to the quality and safety requirements of blood and blood components
National Blood Center