By far when someone mentions blood donation, what we think of first is whole blood donation which is the most common type of donation performed in blood collection centres. But interestingly enough there are other types of donations which we call aphaeresis.
Whole blood, as present in the veins, is collected from the donor and is later processed and separated into different products/components in the processing laboratories.
There are different reasons why one donates whole blood. Normally blood donations are added to the existing pool of units readily available for patients, others may opt to donate autologous and directed donations.
Apheresis is a Greek word which means 'to extract'. The process of apheresis involves the extraction of a component of blood (component refers to a part of whole bloode.g. red cells, platelets, plasma) by means of a special machine, thus the donor will give only one particular component of his/her blood.
Only particular donors can donate specific blood products and the NBTS staff carefully select these from among regular donors.
There are two main types of apheresis; plasmapheresis which is the extraction of plasma and cytapheresis which is the extraction of some type of cell. In our donation centres we perform platelet collection only.
Whole Blood - Pool
Whole blood donation is when a person donates all the different types of cells that constitute our blood. This is the most common type of donation. The blood that is collected is placed in blood bank stores (pool), and eventually supplied to various hospitals.
Autologous Donation
(When a person gives blood intended for oneself)
When a person gets to know that s/he will be undergoing an elective surgery and would be needing blood, one can ask about the procedure to give blood to oneself. This procedure requires that the person is eligible to donate blood as per normal requirements. This means that although the person would be donating blood for oneself, the principles for blood donation will be the same as when a regular donor donates blood. Therefore, an autologous donor may be deemed ineligible to donate blood just like any other donor even if donating for oneself.
As from five weeks prior to the operation, the patient should discuss with the consultant who will carry out the procedure whether or not he agrees that an autologous donation should be taken. If the consultant agrees, he should complete a
form which can be obtained from the National Blood Transfusion Centre or
downloaded. Despite this, a detailed discussion has to take place regarding the procedure and the final decision will ONLY be taken by the doctor examining the person before blood donation. In the case that the patient would not need to be transfused during the operation, that blood will not be used on someone else since it was bled strictly as autologous.
Direct Donation
(A donation intended to be supplied to a specific patient other than self)
Another service that the Blood Transfusion Center offers (although not recommended), is that of donating blood to somebody specific.
This procedure is not recommended since it was discovered, from various studies, that this kind of donation places the patient at a greater risk than regular donations. Apart from this, when blood is taken from close relatives, eg parents or siblings, this blood has to go through a certain amount of radiation to make sure that all white cells are destroyed. This is important so that certain reactions during the transfusion are avoided. This is called GRAFT VERSUS HOST DISEASE.
When this type of donation takes place, the blood is reserved for a specific patient, and similarly to the procedure mentioned earlier, the blood may not be used on someone else, even if the patient would not need the transfusion.
In these cases, it is important that the patient gives
consent that s/he will accept the blood from these donors with all the potential risks. The
consent form can be obtained from the Blood Donation Centre or it can be downloaded
here. It is important that these donors come over to this Centre at least one week prior to the donation.
Although a patient signs that he accepts to receive blood from these persons, the donors still have to go through all the procedures as if they were regular donors, meaning that they have to go through the questionnaire, and the examining doctor at the Centre decides whether or not the donation should take place.
Plasmapheresis
The NBTS harvests plasma from whole blood donations, whereby the plasma is extracted from these in the laboratories. Plasmapheresis is another procedure by which plasma (only) is extracted/ donated using a specialised machine, and no further processing is then required. This latter type of donation will soon be implemented to harvest ‘COVID-19 Convalescent Plasma’ (CCP) from those people who have recovered from this infection. This donation will be used to treat patients with severe symptoms of COVID-19.
Plateletpheresis
The most important type of apheresis is the extraction of platelets from blood which is known as
plateletpheresis.
Plateletpheresis is the process of extracting platelets from whole blood. This can be done in the laboratory but can also be performed as a specific type of donation at the donation area. This is referred to as
Platelet Donation.
Plateletpheresis in the laboratory
Platelets can be collected in the laboratory from freshly collected whole blood. It takes 5 bags of blood of the same group to make one unit or a bag of platelets. These are known as pooled platelets.
Blood Types
The below vidoe from you tube explains blood types. Its interersting, please watch.