Blood Transfusion

Question 1

what is lecuodepletion

Answer 1

removal of white blood cells from blood before transfusion

Question 2

after lecuodepletion what happens to the blood

Answer 2

centrifuged to RBC, platelets and plasma

Question 3

what happens to separated plasma before transfusion

Answer 3

frozen - cryoprecipitate

fractioned to from, factor concentrates, albumin, immunoglobulins

Question 4

what is the normal amount of RBC amount tin males compared to females

Answer 4

male - 130-180 g/L

female - 115 - 165 g/L

Question 5

what is the transfusion time of blood and what affects the speed

Answer 5

1.5-3 hours - warmer the blood the faster the transfusion

Question 6

what are the RBC’s stored with to keep it healthy

Answer 6

electrolytes, glucose, adenine

Question 7

how much does 1 unit of blood raise the haematocrit

Answer 7

1 unit raise Hb by 10g/L

Question 8

which situations would you use a blood transfusion

Answer 8

significant bleeding, acute anaemia,

Question 9

when would you want to avoid transfusion

Answer 9

patients with chronic anaemia due to iron deficiency or vitamin deficiencies

Question 10

what is the normal blood platelet volume

Answer 10

150-450 x 10^9/ L

Question 11

what is the storage volume and transfusion time for platelets

Answer 11

250-350 ml about 30 minutes

Question 12

what are the two ways to collect platelets

Answer 12

pooled - 4-6 donors pooled together to from therapeutic dose

aphaeresis - blood cycled through aphaeresis machine - only platelets removed from blood and then return to donor (reduces infection risk)

Question 13

what is the risk of platelet transfusion

Answer 13

infection risk from arm and storage pooling

Question 14

when would you do a platelet transfusion and when should you avoid it

Answer 14

prevent and treat bleeding in patient with thrombocytopenia or platelet dysfunction

avoid with: immune/thromboctic purpura or heparin induced thrombocytopenia

Question 15

what is good about frozen plasma and what is the therapeutic dose

Answer 15

contains all clotting factors but levels V and VIII diminished after 6 hours of thawing

12-15 MI/Kg

Question 16

when would you give fresh frozen plasma and when would you avoid

Answer 16

significant bleeding gin patients with abnormal clotting

avoid with single factor deficiencies or to reverse warfarin

Question 17

what do you use to reverse warfarin effects

Answer 17

prothrombin complex concentrate (factor IX complex)

high conc of vit k dependant factors

Question 18

which factors are vit k dependant and can reverse warfarin

Answer 18

2, 7, 9, 10

Question 19

what is cryoprecipitate and what is it used for

Answer 19

one does 6-10 units
extracted from FFP - has fibrinogen, vWF, VIII, XIII

used as source of fibrinogen in acquired coagulopathies

Question 20

what are the acute risks of transfusions

Answer 20

acute < 24 h
immunological - anaphylaxis, acute haemolytic transfusion reaction, TRALI (transfusion - related acute lung injury)

non-immunological - bacterial contamination, TACO (transfusion associated circulatory overload), FNHTR (febrile non-haemolytic transfusion reaction)

Question 21

what are the delayed risks of transfusions

Answer 21

immunological - delayed haemolytic reaction, post transfusion purpura
iron overload

Question 22

what are the most common reactions from transfusions

Answer 22

allergic

FNHTR - febrile non-haemolytic transfusion reaction

Question 23

what is FNHTR and what’s the cause

Answer 23

febrile non-haemolytic transfusion reaction
rise in temp, tachycardia, resolves after disuse

cytokines or other bio molecules

Question 24

what is TACO

Answer 24

transfusion-associated circulatory overload
acute left ventricular failure with pulmonary oedema
24h after transfusion

Question 25

what is the most common cause of transfusion related deaths

Answer 25

TACO

Question 26

what happens if there’s transfusion with bacterial contaminated components

Answer 26

onset in 15 mins
fatal 35% of the time
rigours, high fever
confirm with blood culture

Question 27

what cause acute haemolytic reaction in transfusions

Answer 27

most often ABO mismatch - recipient has pre-formed antibodies against antigens expressed on the transfused RBC’s

Question 28

what are the signs and symptoms of acute haemolytic reaction

Answer 28

fever, back pain, DIC

Question 29

describe pre-transfusion testing of patients

Answer 29

determination of ABO and Rh(D) - crossmatching

check if there is an agglutination

Question 30

what causes delayed haemolytic reaction

Answer 30

post transfusion formation of new immune IgG antibodies against RBC other than ABO

Question 31

what are the features and testing for delayed haemolytic reaction

Answer 31

fatigue, jaundice

direct anti-globin test to detect antibodies bound on RBC’s - coombs test

Question 32

what is coombs test used for

Answer 32

delayed haemolytic reaction

Question 33

what are the clinical features of allergic responses to transfusion

Answer 33

rash, urticaria, pruritic, periorbital oedema

anaphylaxis - especially with IgA and anti-IgA are at higher risk

Question 34

what is TRALI

Answer 34

transfusion-related acute lung injury

immune mediated reaction due to antibodies against leucocytes causing leaky pulmonary capillaries

Question 35

what are the features of TRALI

Answer 35

hypoxaemia, no evidence of volume overload