Blood Transfusions Flashcards
Definition of group and save?
A group and save is the sample processing.
It consists of a blood group and an antibody screen to determine the patients group and whether or not they have atypical red cell antibodies in their blood. If atypical antibodies are present the laboratory will do additional work to identify them.
What is a cross match?
A crossmatch is when the laboratory actually provides red cells products for the patient. It is not possible for the laboratory to provide crossmatched blood without having processed a group and save sample first.
Causes of delayed blood transfusion reaction >24 hours?
Delayed haemolytic transfusion
Graft vs host disease
Post-transfusion purpura
Features of delayed haemolytic reaction?
Occurs within 1 week
Extravascular haemolysis IgG mediated
Features of Graft vs host disease?
Diarrhoea, maculopapular rash, skin desquamation. Especially in immunosuppressed.
How to prevent graft vs host disease?
Irradiate blood components.
Causes of acute blood tranfusion reactions <24 hours?
Anaphylaxis- risk increased with IgA deficiency
ABO incompatability- intravascular haemolysis IgM mediated
Bacterial contamination- more commonly occurs with platelet transfusion
Febrile non-haemolytic transfusion reaction
Transfusion associated circulatory overload- signs of heart failure
Transfusion related acute lung injury- absence of heart failure
Features of allergic/anaphylactic reaction?
Type 1 hypersensitivity reaction against PLASMA proteins in transfused blood.
IGA DEFICIENT INDIVIDUALS AT RISK
Must receive blood products without IgA
Presentation: Urticaria, pruritus, fever, wheezing, hypotension, respiratory arrest, shock
Onset: within minutes to 2-3 hours
Features of acute haemolytic transfusion reaction?
Type 2 hypersensitivity reaction. INTRAVASCULAR HAEMOLYSIS (ABO BLOOD GROUP INCOMPATIBILITY) or extravascular haemolysis (host antibody reaction against foreign antigen on donor RBCs)
Presentation: FEVER, HYPOTENSION, tachypnea, ABDO PAIN, LOIN PAIN, HAEMOGLOBINURIA (intravascular haemolysis) DARK URINE, jaundice (extravascular)
WITHIN 1 HOUR
Features of febrile non haemolytic blood transfusion reaction?
Mild Fever
Rigors
Occurs after pregnancy when anti leukocytic antibodies can form, this can causse a reaction in leukocytes to subsequent transfusions.
Features of transfusion related acute lung injury?
Respiratory distress- significant breathlessness
Normal CVP
Non cardiogenic pulmonary oedema
WITHIN 6 HOURS
DRY COUGH, DYSPNOEA AND FEVER
Which deficiency increases risk of anaphylaxis in blood transfusions?
IgA
How to reduce risk of graft versus host disease?
Irradiate blood products prior to transfusion
Features of bacterial infection in blood transfusion?
High fever
Rigors
Hypotension/shock
Features of post transfusion purpura?
Example BB qs:
A 36 year old Italian gentleman presented with severe bruising across the dorsal aspect of his left arm one week post-transfusion. FBC results included: Hb = 15g/dL, platelets = 8x109/L and WBC = 5.5x109/L.
A 30 year old female patient develops red/purple spots on both legs after receiving a blood transfusion during a Caesarean section several days previously.
