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Erythrocytapheresis is an apheresis procedure by which erythrocytes (red blood cells) are separated from whole blood. It is an extracorporeal blood separation method whereby whole blood is extracted from a donor or patient, the red blood cells are separated, and the remaining blood is returned to circulation.
For the separation of erythrocytes, whole blood is passed through an apparatus that isolates the red blood cells from the remaining components. In erythrocytapheresis, centrifugation is the most commonly used red blood cell fractionation method. This is because the hematocrit, or the percentage of blood volume taken up by red blood cells, is present in the highest percentage of all blood cell components in the solid portion of blood. Therefore, since erythrocytes have the highest specific weight in comparison to other solids in blood, they can easily be separated using centrifugation. Whole blood is spun down in a spinning bowl centrifuge and the bottom layer, concentrated with erythrocytes, sediments to the bottom. These are separated and the rest of the blood can be retransfused.
Centrifugal sedimentation is the most used process by which erythrocytapheresis occurs. In this method, patient or donor blood is collected and processed into an erythrocyte concentrate with a high hematocrit content. This exhausted, pre-filtered blood is collected in a suitable reservoir and pumped into a rotating centrifuge. The centrifugal force will separate the red blood cells from other cells due to their high specific weight. These cells can then be collected. A separate washing step will lead to the removal of plasma parts which will further purify and concentrate erythrocytes. The remaining blood, consisting of blood plasma, leukocytes, platelets, stem cells, lipids, and other solids will then be retransfused into the patient or donor.
The advancement of centrifugation and membrane filtration methods is essential to the development of erythrocytapheresis. In addition, blood separation on microdevices containing capillary channels has been identified as a potential blood cell fractionation method.[ citation needed ] Other plasma and blood cell separation techniques are being explored based on magnetophoresis, electrophoresis, microchannel bends, and ultrasound standing waves.[ citation needed ]
Therapeutic erythrocytapheresis is commonly used to remove red blood cells in patients experiencing sickle cell crisis. The affected erythrocytes are removed while the rest of the blood is retransfused. This blood separation is also used in patients with severe malaria. After removal of the affected cells, the patient can then be transfused with a dose of normal red blood cells.
Erythrocytapheresis can also be used for blood donations. The procedure is commonly done using automated red blood cell collection which involves the removal of two units of red blood cells. This includes either two standard units of red blood cells or one unit plus of red blood cells and another of either plasma or platelets. The advantage to the donor is the use of smaller needles and saline compensation, as well as more convenient donating schedules (the no-donation period following apheresis is twice as long as that for a single unit). The advantage to the blood bankers is the on-line separation into standardized RBC masses with the subsequent reduction in testing, data entry and staffing. This process is commonly referred to as 'power reds', 'double reds' or 'double red cell apheresis'. [1]
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek erythros 'red' and kytos 'hollow vessel', with -cyte translated as 'cell' in modern usage), are the most common type of blood cell and the vertebrate's principal means of delivering oxygen (O2) to the body tissues—via blood flow through the circulatory system. RBCs take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillaries.
Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but modern medical practice commonly uses only components of the blood, such as red blood cells, white blood cells, plasma, clotting factors and platelets.
Platelets or thrombocytes are a component of blood whose function is to react to bleeding from blood vessel injury by clumping, thereby initiating a blood clot. Platelets have no cell nucleus; they are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow or lung, which then enter the circulation. Platelets are found only in mammals, whereas in other vertebrates, thrombocytes circulate as intact mononuclear cells.
Whole blood (WB) is human blood from a standard blood donation. It is used in the treatment of massive bleeding, in exchange transfusion, and when people donate blood to themselves. One unit of whole blood brings up hemoglobin levels by about 10 g/L. Cross matching is typically done before the blood is given. It is given by injection into a vein.
Blood plasma is a light amber-colored liquid component of blood in which blood cells are absent, but which contains proteins and other constituents of whole blood in suspension. It makes up about 55% of the body's total blood volume. It is the intravascular part of extracellular fluid. It is mostly water, and contains important dissolved proteins, glucose, clotting factors, electrolytes, hormones, carbon dioxide, and oxygen. It plays a vital role in an intravascular osmotic effect that keeps electrolyte concentration balanced and protects the body from infection and other blood-related disorders.
A blood bank is a center where blood gathered as a result of blood donation is stored and preserved for later use in blood transfusion. The term "blood bank" typically refers to a department of a hospital usually within a Clinical Pathology laboratory where the storage of blood product occurs and where pre-transfusion and Blood compatibility testing is performed. However, it sometimes refers to a collection center, and some hospitals also perform collection. Blood banking includes tasks related to blood collection, processing, testing, separation, and storage.
The hematocrit, also known by several other names, is the volume percentage (vol%) of red blood cells (RBCs) in blood, measured as part of a blood test. The measurement depends on the number and size of red blood cells. It is normally 40.7–50.3% for males and 36.1–44.3% for females. It is a part of a person's complete blood count results, along with hemoglobin concentration, white blood cell count and platelet count.
A blood donation occurs when a person voluntarily has blood drawn and used for transfusions and/or made into biopharmaceutical medications by a process called fractionation. Donation may be of whole blood, or of specific components directly (apheresis). Blood banks often participate in the collection process as well as the procedures that follow it.
Apheresis is a medical technology in which the blood of a person is passed through an apparatus that separates out one particular constituent and returns the remainder to the circulation. It is thus an extracorporeal therapy.
Plasmapheresis is the removal, treatment, and return or exchange of blood plasma or components thereof from and to the blood circulation. It is thus an extracorporeal therapy, a medical procedure performed outside the body.
Plateletpheresis is the process of collecting thrombocytes, more commonly called platelets, a component of blood involved in blood clotting. The term specifically refers to the method of collecting the platelets, which is performed by a device used in blood donation that separates the platelets and returns other portions of the blood to the donor. Platelet transfusion can be a life-saving procedure in preventing or treating serious complications from bleeding and hemorrhage in patients who have disorders manifesting as thrombocytopenia or platelet dysfunction. This process may also be used therapeutically to treat disorders resulting in extraordinarily high platelet counts such as essential thrombocytosis.
Leukoreduction is the removal of white blood cells from the blood or blood components supplied for blood transfusion. After the removal of the leukocytes, the blood product is said to be leukoreduced.
Fresh frozen plasma (FFP) is a blood product made from the liquid portion of whole blood. It is used to treat conditions in which there are low blood clotting factors or low levels of other blood proteins. It may also be used as the replacement fluid in plasma exchange. Using ABO compatible plasma, while not required, may be recommended. Use as a volume expander is not recommended. It is given by slow injection into a vein.
Intraoperative blood salvage (IOS), also known as cell salvage, is a specific type of autologous blood transfusion. Specifically IOS is a medical procedure involving recovering blood lost during surgery and re-infusing it into the patient. It is a major form of autotransfusion.
Blood fractionation is the process of fractionating whole blood, or separating it into its component parts. This is typically done by centrifuging the blood.
Packed red blood cells, also known as packed cells, are red blood cells that have been separated for blood transfusion. The packed cells are typically used in anemia that is either causing symptoms or when the hemoglobin is less than usually 70–80 g/L. In adults, one unit brings up hemoglobin levels by about 10 g/L. Repeated transfusions may be required in people receiving cancer chemotherapy or who have hemoglobin disorders. Cross-matching is typically required before the blood is given. It is given by injection into a vein.
The New Zealand Blood Service is the provider of blood services for New Zealand. The service is a Crown entity responsible to New Zealand’s Parliament and is governed by a Board appointed by the Minister of Health.
Autotransfusion is a process wherein a person receives their own blood for a transfusion, instead of banked allogenic (separate-donor) blood. There are two main kinds of autotransfusion: Blood can be autologously "pre-donated" before a surgery, or alternatively, it can be collected during and after the surgery using an intraoperative blood salvage device. The latter form of autotransfusion is utilized in surgeries where there is expected a large volume blood loss – e.g. aneurysm, total joint replacement, and spinal surgeries. The effectiveness, safety, and cost-savings of intraoperative cell salvage in people who are undergoing thoracic or abdominal surgery following trauma is not known.
Red blood cells (erythrocytes) from donors contain normal hemoglobin (HbA), and transfusion of normal red blood cells into people with sickle cell disease reduces the percentage of red cells in the circulation containing the abnormal hemoglobin (HbS). Although transfusion of donor red blood cells can ameliorate and even prevent complications of sickle cell disease in certain circumstances, transfusion therapy is not universally beneficial in sickle cell disease.
Therapeutic apheresis is a treatment modality that processes whole blood through medical technologies for the purpose of separating it into components and removing identified pathological cellular or plasma components. Pediatric therapeutic apheresis treatments includes plasma exchange, red cell exchange/depletion, stem cell collections, leukodepletion and plasma exchange with secondary plasma device. There are considerations to be made when performing apheresis in pediatric patients, with the understanding that the apheresis technology and equipment used to perform adult apheresis are also used for pediatric apheresis. Additionally, pediatric patients require advance monitoring and clinical accommodations, due to their smaller body mass and immature body system functions, to safely perform treatments.