The 3 types of blood donation:

In times past, it was common for a major surgery to use up to 20 units of blood to save a patient. Blood was blood and that was it. These days it’s used much more effectively. When somebody donates whole blood, it’s separated into red blood cells (RBC), plasma and platelets which are then processed even further depending on your specific proteins, antigens, antibodies and immunoglobulins. Below I’ll describe each type of donation in detail, but first, a little history.

Red blood cells (RBC) have antigens that define your type. You can have either A, B or both, or neither. RBC is mainly useful for the hemoglobin, which is the protein that carries oxygen. Also in your blood is platelets, which are what clot your blood. They are tiny little cell fragments that respond to a signal and clump together to seal leaks. Platelets and RBCs float in a liquid called plasma, which also contains a tonne of other proteins and products.

Plasma compatibility is in some way the opposite to your blood type. If you have blood type A, your RBCs have the A antigen and none of the A antibodies in your plasma, but you do have B antibodies. So if you receive transfusion of type B RBCs, your plasma and those RBCs will battle it out. If you are blood type AB, then you have neither A nor B antibodies in your plasma, and can receive whatever type RBCs you like. If you have type O blood, then you have BOTH types of antibodies in your plasma and can only receive type O RBCs or else your plasma will fight them. In this way, blood type O is the universal donor while type AB is the universal receiver of RBCs.

However, because blood type AB have neither of the antibodies in their plasma, their PLASMA will never battle any RBCs. In this sense, blood type AB is the universal donor of PLASMA and type O is the universal receiver of plasma.

Platelets work a little differently, because they express some but not all of the antigens on RBCs and they also need to be stored in some plasma:

• Type AB, B and O platelets are only given to the same type.
• AB platelets will not harm a patient of another blood type, but the patient will kill off many of the platelets, rendering the transfusion only partially effective.
  
• Type A sub group 1 can only be received by Type A.
• Type A sub group 2 can be received by Type A and O.

So, instead of giving a desperate bleeding patient 20 units of the same blood type, it is more efficient to give them 10 units of their compatible RBCs and 10 units of their compatible plasma. This means that more blood types can be mixed together for a single patient in immediate danger. Of course, if you have plenty of the identical blood type, that is always preferred, but this has opened up options.

Now onto platelets. When somebody is suffering dangerous bleeding risk, such as from a serious car accident, or heart/brain/eye surgery, often they will bleed for a long time, requiring many units of blood that will simply continue to bleed. Transfusing them with platelets will accelerate their healing both on a large obvious scale, and a small micro-bleeding scale during recovery. Reducing the overall need for blood.

Example transfusion:
Old system = 10 units of the identical blood type.
New system = 2 units of compatible RBCs, 2 units of compatible plasma, 1 unit of platelets.

As you can see, the efficiency and capability of blood transfusions is increased. Less blood needs to be used, and more options are available.

But it didn’t end there. Turns out that plasma can be used to make over a dozen different treatments for specific illnesses, meaning that you don’t need to use an entire unit of plasma, you can just use a fraction of the stuff you really need. Platelets, instead of requiring 4 donors to make just one unit, can be all taken from a single donor at once with apheresis.

Whole Blood:

Duration: 5-10 min process, 40 min total.
Quantity: 500ml, 30 for testing, 470 usable.
Makes: 210ml packed RBC, 250ml plasma, 60 Billion platelets.
Requirements: Hemoglobin 135-175 for male, 125-155 for female.
Lasts: Can be refrigerated for 42 days.
Best donor: O or A.
Uses: For packed RBC include trauma, surgery, anemia, blood loss and blood disorders such as sickle cell.
What happens: The most straightforward of donation types. You sit in a chair and the nurse gives you a needle. First they take 3 vials of blood for testing then she hooks a bag into the line. The bag sits on a little rocking table and fills up. It can take up to 15 minutes, but most people are done in less than 10, some even less than 5. You get a bandage and off you go.

Plasma:

Duration: 45 min process, 75 min total.
Quantity: 250ml to 900ml.
Makes: 1 to 3 units of plasma, in turn making immunoglobulins, Intragam P, albumin, cryoprecipitate, biostate and Factor 8 concentrate.
Requirements: Hemoglobin 135-175 for male, 125-155 for female, 1 successful whole blood donation in the past 2 years, aged 18-70 for males or 20-70 for females.
Lasts: Can be frozen for a year.
Best donor: AB, B or A.
Uses: Burn patients, shock, bleeding disorders, Von Willebrand disease, haemophilia, liver & kidney disease, immune deficiencies, immunisations, Rhesus disease prevention.
What happens: This time, instead of the blood going straight into a bag, it goes into a machine which separates the plasma from the rest of your blood. The plasma goes into a bag, then the machine sends the rest back into your arm. For this reason, your veins need to be bigger than a regular whole blood donation would require. The machine “draws” blood for about 10 minutes, then “returns” it for about 10 minutes. This is repeated until you’re done. A small amount of anticoagulant is put in to prevent clumping and this can make your lips and nose tingle or give you a metallic taste in the mouth. It goes away as soon as you’re finished. Also, sometimes to replace how much fluid you’re losing, it will also return some saline solution with your blood. This can feel chilly in your arm and some people will feel cold all over. The nurses look after you and have blankets ready. They also provide newspapers and snacks.

The amount of plasma taken depends on your size. Your first 2 donations will be 13% of your body fluid, next 2 will be 16% and after that, if all is well, you can donate up to 19% of your body fluid.

Platelets:

Duration: 60-110 min process, up to 2 1/4 hours total.
Quantity: 240 to 720 Billion platelets and 200ml to 600ml of plasma
Makes: 1 to 3 units of platelets for adults, or 4 to 12 units for pediatrics. Better quality than platelets pooled together from whole blood donations since recipient is exposed to fewer donors.
Requirements: Male only, females may not donate platelets in Australia. 1 successful plasma donation in the past year, aged 18-70, no recent dental work, no aspirin in the past 7 days, no neurofen/ibuprofen or other anti-inflammatory medicine in the past 3 days, no current cuts, abrasions, sores nor rashes, no recent gastric upset, abdominal pain, diarrhea nor vomiting.
Lasts: Only 5 days.
Best donor: O or A.
Uses: Cancer treatments, organ transplants, surgery. Leukemia and other cancer patients who undergo chemotherapy may not be able to produce platelets and can have spontaneous bleeding throughout their body without a constant supply from donors.
What happens: When you first see the platelet apheresis machine it looks a little more confusing and complicated than the plasma one. Fundamentally it isn’t, but it was designed more recently and is therefore quite shiny. Your veins must be a nurse’s dream to be able to do this, since a slight mistake means the pack needs to be thrown away and they are quite expensive. You get hooked up like one the plasma machine only this time, the cycle of “draw” and “return” happens much faster, like 1-2 minutes each way. The machine spins constantly, forever separating plasma and platelets from red blood cells. Your blood “draws” directly into the centrifuge and a little chamber slowly fills up with the separated RBCs and plasma which will empty itself back into you once it starts to get full. You will probably get more anticoagulant over the duration and may feel tingly all up your arm. Be sure to let the nurses know what’s happening. They give you a couple of quick-eze to help, if you’re lucky you get the soft minty chews instead of the powdery white tablets.

The amount of platelets taken depends on a few factors. You cannot lose more than half your platelets, your platelet concentration cannot fall below 150 Billion per Litre and you must be able to give at least 240 Billion in 110 minutes. If you are able to give more than 480 Billion in 110 minutes then your machine will attempt to do so, otherwise it will cut out much earlier. Some people are only on there for 60 minutes. On my last visit, I sat there for 95 minutes and they took 580 Billion platelets and 400ml of plasma.