Packed Red Blood Cells (PRBCs)A unit of PRBCs is red blood cells centrifuged out from whole blood. The hematocrit of PRBCs is approximately 55%. This type of blood product is often given in the case of acute bleeding. In the ICU, it seems like the majority of patients receiving PRBCs are GI bleeders or patients with complications from surgery.
Fresh Frozen Plasma (FFP)One unit of FFP is taken all of the plasma from a unit of whole blood. It contains many factors necessary for clotting and is often given to reverse a patient’s INR. When patients receive multiple units of FFP, they are often given Vitamin K to aid in increasing the patient’s ability to coagulate.
SerumSerum (off-the-clot) is derived from whole blood donations and then allowed to clot spontaneously prior to centrifugation. After separating the serum from the cellular components, it is allowed to undergo secondary clotting to ensure removal of all remaining components necessary for the clotting cascade. It is centrifuged again, allowing the remaining serum to be drawn off and packaged according to your requirements.
Platelets are produced in two ways:
Whole blood donations are centrifuged and the buffy coats (between the red cell and plasma layers) from four donations are pooled in the plasma of one of the donors (male, to reduce the risk of transfusion-related acute lung injury).
An ATD of platelets is obtained from a single donor by apheresis.
Apheresis, from the Greek word for “to take away”, is the process of taking whole blood from a donor or patient and dividing it into its component parts namely, plasma, red cells, platelets and white blood cells. This can be automated by way of an apheresis machine, which often uses a centrifuge to accomplish the separation. Once the blood is separated, the desired component or components may be just removed, in the case of a donor, or removed and replaced in the case of a patient. With patients, the removed component may also be replaced with donor blood, plasma or blood substitutes such as 5% Albumin or normal saline and then returned to the patient. This is typically performed in a continuous flow process such that the donor or patient has only a small percentage of their total blood volume in the machine at any given time. Apheresis is mostly commonly used for platelet donation. When apheresis is performed on patients it is called Therapeutic apheresis, where typically the goal is to remove substances in the plasma (plasmapheresis) and replace it with fresh donor plasma (plasma exchange) or 5% Albumin or normal saline. With some diseases states, the red cells need to be removed, and so a “red cell exchange” may be preformed where the patient’s red cells are replaced with fresh normal donor red cells.
Plasmapheresis involves removing the patient’s blood through a needle with IV line or central catheter and circulating it through a machine where the blood is separated as described above. The plasma, which is the least dense liquid part of the blood, is removed by the machine, discarded and replaced with a blood substitute fluid (typically 5% albumin or normal saline) or fresh donor FFP. The substitute plasma and the patient’s own blood cells (red cells, white cells and platelets) are recombined and then returned to the patient through the venous access.
What Does Plasmapheresis Treat?
- Thrombotic Thrombocytopenic Purpura (TTP)
- Myasthenia Gravis
- Neuromyelitis Optica (NMO)
- Multiple Sclerosis
- Guillain-Barre Syndrome
- Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
- Goodpasture’s Syndrome
- Rapidly Progressive Glomerulonephritis (RPGN)
- Systemic Vasculitis
- Immune Thrombocytopenia (ITP)
- Transplant sensitization
- Transplant rejection (antibody type)
- Waldenstrom’s Macroglobulinemia
- Hyperviscosity syndrome
- Recurring focal segmental glomerulosclerosis (FSGS)
- Other rarer diseases
Potential Side Effects
Plasmapheresis is a safe procedure with a few possible side effects. You may have discomfort at the needle site and occasional fatigue, low blood pressure, dizziness, feeling cold and tingling in the fingers and around the mouth. Notify your nurse immediately if you experience any of these symptoms.
Our apheresis services include:
- 24/7 Therapeutic Apheresis Services with an expert team of nurses (over 40 years combined hands-on experience)
- Guaranteed response time to start a procedure of 3 hours or less for emergencies
- Education on therapeutic apheresis from physician experts
- 24/7 physician-to-physician consultation
- Ability and experience with pediatric patients
- Ability to perform stem cell collections for bone marrow transplant or other indications/clinical trials
- Adhere to Nationally Published, data-supported, ASFA guidelines for apheresis indications
Special Antigen Units
Each donated unit of red cells has thousands of proteins on the cell surface called antigens. These antigens can function in a myriad of capacities, such as cell structure support, ligand receptors, and cell signaling among many other examples.
For each individual class of receptors, there are often at least two copies or “genotypes” within a given population of people. The immune systems of those who only have the genes for one type or haplotype will often recognize the antigens of the other haptotype of the same class as “foreign”. Because our immune systems are trained to destroy any antigen or non-self protein that they see as foreign, for example, bacteria, a person may mount an immune response by creating antibodies against antigens of the same class it sees as foreign. This can occur when mismatched blood is given to patients or in other words, blood having the opposite antigen type is given to patients in the hospital. Because there are at least 44 of these significant antigens that can cause a person to mount an immune response, often we try to match as many of these antigens we can, of course, including the ABO, RH groups as well when we transfuse blood. This strategy works for most people.
Despite this, however, when a patient does make antibodies to perhaps a rare antigen of the 44, it can cause hemolysis or destruction of any red cells transfused that contain that antigen which in some cases, is very common. The result is sometimes that patients may need the blood of a particular type that is more rare and difficult to find. These units are called Special Antigen Units or SAUs.
ITM has developed a program to genotype a select group of our donors to have their antigen type kept on file should such an SAU be needed. A person who can donate blood that falls into the category of rare would be considered an SAU. That donor may be called back and asked to contribute on a rolling basis to help save someone’s life in the hospital who can only receive blood from someone like them. These special donors are indeed highly valued for the patients and their caregivers.