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Lecture 29
Transfusion Medicine II
Question | Answer |
---|---|
What situation indicates the tranfusion of whole blood? | When both red cells and volume are needed. |
Why can't an A or B blood type individual be transfused with large volumes of O whole blood? | The anti-A and anti-B antibodies in the O plasma will eventually react with the recipient's cells causing hemolysis. |
How much serum is found in a unit of packed red blood cells? | About 20 cc per unit |
What ABO type can recieve type O packed red blood cells? | All ABO groups |
What ABO type can recieve any ABO type packed red blood cells? | Blood type AB |
What is the general indication for packed red blood cells? | When the patient exhibits signs and symptoms of an oxygen-carrying deficit. |
How many tranfusions of D-positive blood can be given to an D-negative individual? | Only one. |
What are the indications for transfusion of fresh frozen plasma? | 1)Acquired coagulopathies where PT and PTT > 1.5 times the upper limit of normal 2)Factor replacement for bleeding where no factor concetrate is available. |
What ABO type can recieve type AB fresh frozen plasma? | All ABO groups |
What ABO type fresh frozen plasma can be safely transfused into a type O recipient? | Type O fresh frozen plasma |
What are the indications for platelet transfusions? | 1)Plt count < 50,000 and there is either hemorrhage or an invasive procedure anticipated 2) prophylaxis when plt count <10,000 3) when there bleeding int he presence of a qualitative plt defect |
What are the ABO compatibilty requirements for safe transfusion of platelet concentrates. | None. Platelets of any ABO type can be transfused into any recipient. |
Can a D negative patient be immunized aganist the D antigen from platelet concentrate transfusion? | Yes, a few red cells may be present in platelet concetrates; therefore a D negative patient can be immunized by a platelet product from a D positive donor. |
What complication can occur with chronic platelet transfusions? | Antibodies can be formed aganist HLA antigens present on transfused platelets. Once these antibodies are made, they can accelerate platelet destruction. |
What can prevent alloimmunization to HLA antigens from frequent platelet concetrate transfusion? | Use of leukocyte reduced blood products |
What are the indications for leukocyte reduced blood products? | 1)Prevent recurrent febrile nonhemolytic transfusion reactions 2)Prevent transmission of CMV in patients where CMV infection is life threatening 3)Prevent alloimmunization to platelets |
What are leukocyte reduced blood products? | Blood products which have been filtered to remove 3 to 4 logs of white blood cells. |
What types of blood products require leukocyte reduction? | Platelet concetrate and red blood cells |
What blood products do not require leukocyte reduction? | Fresh frozen plasma and cryoprecipitate becuase WBCs do not survive the freezing process. |
What is the therapy for febrile nonhemolytic transfusion reaction? | Acetaminophen and observation |
A transfusion reaction characterized by a temp elevation of 1 deg C or more during or within 2 hours of a transfusion. | Febrile nonhemolytic transfusion reaction |
A transfusion reaction characterized by an immediate type I hypersensitivity reaction caused by exposure to foreign proteins in the transfused unit. | Urticaria |
What are the consequences of transfusion of ABO incompatible whole blood transfusion? | 1)Acute intravascular hemolytic transfusion 2)Hypotension with ensuing renal failure 3)Activation of the coagulation cascade with DIC |
How long after a transfusion does delayed extravascular hemolytic transfusion reaction present? | typically 7-9 days after transfusion |
What subtype of immunoglobulin are responsible for the delayed extravascular hemolytic transfusion reaction? | IgG that were too low a titer to be detected by the antibody screen. |