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Higher platelet transfusion thresholds have been used in premature neonates, but this has been based on limited evidence. [19] There is now evidence that using a high platelet count threshold (50 x 10 9 /L) increases the risk of death or bleeding compared to a lower platelet count threshold (25 x 10 9 /L) in premature neonates. [20]
In a typical set of rules, a platelet donor must weigh at least 50 kg (110 lb) and have a platelet count of at least 150 x 10 9 /L (150,000 platelets per mm³). [2] One unit has greater than 3×10 11 platelets. Therefore, it takes 2 liters of blood having a platelet count of 150,000/mm³ to produce one unit of platelets.
Blood compatibility testing is routinely performed before a blood transfusion.The full compatibility testing process involves ABO and RhD (Rh factor) typing; screening for antibodies against other blood group systems; and crossmatching, which involves testing the recipient's blood plasma against the donor's red blood cells as a final check for incompatibility.
A massive transfusion protocol is used when significant blood loss is present such as in major trauma, when more than ten units of blood are needed. Packed red blood cells, fresh frozen plasma, and platelets are generally administered. [131] Typical ratios of fresh frozen plasma, platelets and packed red blood cells are between 1:1:1 and 1:1:2 ...
Finally, platelets may be transfused as part of a massive transfusion protocol, in which the three major blood components (red blood cells, plasma, and platelets) are transfused to address severe hemorrhage. Platelet transfusion is contraindicated in thrombotic thrombocytopenic purpura (TTP), as it fuels the coagulopathy.
The ABO blood group system is used to denote the presence of one, both, or neither of the A and B antigens on erythrocytes (red blood cells). [1] For human blood transfusions , it is the most important of the 44 different blood type (or group) classification systems currently recognized by the International Society of Blood Transfusions (ISBT ...
The term human blood group systems is defined by the International Society of Blood Transfusion (ISBT) as systems in the human species where cell-surface antigens—in particular, those on blood cells—are "controlled at a single gene locus or by two or more very closely linked homologous genes with little or no observable recombination between them", [1] and include the common ABO and Rh ...
Platelets for transfusion can also be prepared from a unit of whole blood, whereby 4 or 5 buffy coats are pooled to produce a platelet component. Some blood banks have replaced this with platelets collected by plateletpheresis because whole blood platelets, sometimes called "random donor" platelets, must be pooled from multiple donors to get ...