CP36 - Blood transfusion Flashcards
what are the different component of blood?
RBC, platelets, plasma
what is leucodepletion
removal of RBC during processing of the blood before transfusion
what can be derived from the plasma
fresh frozen plasma, cryoprecipitate, fractionation (for production of albumin, immunoglobulin, factor conc.)
what is cryoprecipitate
derived from blood and contain many coagulating factors
what is transfusion threshold
lowest conc of Hb that is no associated with symptoms of anaemia - different with different groups of ppl
what is the amount of Hb that should be transfused to patients who have mild symptoms of anaemia
what is the amount of Hb that should be transfused to patients who have cardiovascular disease
when is transfusion required when acute anaemia due to blood loss
blood loss more than 1.5L
what is the transfusion threshold for chronic anaemia
80-100g/L
what can happen to patients who are regular transfusion?
iron overload
what is the transfusion threshold for chronic anaemia due to inherited anaemias
90-95 g/L
what temp is platelets stored at?
22 degree C and for 5 days
how is platelet collected?
not blood donation but apheresis (donate only platelet)
what is platelet transfusion used for?
massive haemorrhage, bone marrow failure, prophylaxis for surgery
what temp is fresh frozen plasma stored at?
-30 degree C up to 24 months
when will you not transfuse fresh frozen plasma
patient on warfarin or warfarin overdose
what is group and screen
determination of ABO and Rh(D) group,
screened for antibodies against other clinically significant blood group antigens
what is crossmatching
Patients plasma is mixed with aliquots of donor red cells to see if a reaction (agglutination or haemolysis) occurs
what are the 2 different types of transfusion reactions
acute transfusion reactions 24 hrs
what are the general subclassifications for transfusion reactions
immunological & non-immunological
what happens is acute transfusion reactions
immuno - Acute haemolytic transfusion reaction
ABO incompatibility
Allergic /anaphylactic reaction
TRALI (Transfusion-related acute lung injury)
non - Bacterial contamination
TACO (transfusion associated circulatory overload)
Febrile non-haemolytic transfusion reaction
what happens is delayed transfusion reactions
immuno - Transfusion-associated graft-versus-host disease (TA-GvHD)
Post transfusion purpura
non-immuno - Transfusion Transmitted Infection (TTI) –viral/prion
what is the pathogenesis of acute haemolytic reaction
ABO incompatibility and all the symptoms are caused by the release of free haemoglobin
what are some examples consequences of acute haemolytic reaction.
deposition of Hb in the distal renal tubule results in acute renal failure.
stimulation of coagulation results in microvascular thrombosis
stimulation of cytokine storm
Scavenges NO resulting in generalized vasoconstriction
what are some signs and symptoms for acute haemolytic reaction
fever and chills back pain infusion pain hypotension/shock haemoglobinuria increased bleeding chest pain sense of impending death
what are some clinical features in delayed haemolytic reaction
fatigue, jaundice, fever
what causes delayed haemogobulin reaction
immune IgG antibodies against RBC antigen other than ABO
what is the cause of transfusion related acute lung injury
Donor has antibodies to recipient’s leukocytes
activated WBC lodge in pulmonary capillaries
release substances that cause endothelial damage and capillary leak
what are some symptoms for transfusion-associated circulatory overload?
sudden dyspnea orthopnoea tachycardia hypertension hypoxemia
what causes Febrile non-haemolytic transfusion reactions
are due to cytokines or other biologically active molecules that accumulate during storage of blood components
