Blood transfusion

Question 1

How are blood components obtained?

Answer 1

centrifugin anticoagulated blood to separate into red cells, buffy coat and plasma

Question 2

How are blood products obtained?

Answer 2

subjecting human plasma to a manufacturing process to obtain various plasma fractions

Question 3

What makes blood products more risky than blood components?

Answer 3

blood products are in batches from thousands of donations compared to 1-4 donors so higher risk of infection

Question 4

How many people make up a pool of platelets?

Answer 4

4 standard blood donation

Question 5

What is platelets-apheresis?

Answer 5

complete adult dose of platelets from a single donor

Question 6

What are the anticoagulatns used in transfusion?

Answer 6

citrate-based

Question 7

What tests are carried out on donated blood?

Answer 7

HIV 1 and 2; HCV; HBV; syphilis; HTVL 1 and 2; HEV

Question 8

What temperature must red cells be stored at?

Answer 8

4 degrees +/-2

Question 9

What is the shelf life of red cells?

Answer 9

35 days

Question 10

How long can red cells be out of the fridge before thye cant be put back in?

Answer 10

30 minutes

Question 11

Once out of the fridge, how long should red cells be transfused in?

Answer 11

within 4 hours

Question 12

How are platelets stored?

Answer 12

22 degrees with continual agitation

Question 13

What is the shelf life of platelets?

Answer 13

7 days if bacterial monitoring system is employed

Question 14

When should you transfuse after taking platelets out of storage?

Answer 14

within 1 hour

Question 15

what should FFP be stored at?

Answer 15

-30

Question 16

What is the shelf life of FFP?

Answer 16

3 years

Question 17

Why should platelets not be put in a fridge?

Answer 17

cold activates platelets and wontactivate again

Question 18

What ABO blood group has no ABO antibodies?

Answer 18

AB

Question 19

What type of antibody are ABO antibodies?

Answer 19

IgM as ABO antigens are constantly changing by small amounts

Question 20

What chromosome is ABO blood group inherited on?

Answer 20

9

Question 21

Why do most of us not have antibody against Rh in the blood?

Answer 21

no bacteria carry substance that resembles Rh(D)

Question 22

What is blood group determination based on?

Answer 22

agglutination phenomenon

Question 23

What are the commonest irregular red cell antibodies?

Answer 23

anti-D; anti-K; anti-c; anti-E; anti-Fya

Question 24

What is length of time non-urgent transfusion of one unit of red cell conentrate generally?

Answer 24

2-3 hours

Question 25

What might bubbles in the blood bag indiacte?

Answer 25

bacterial contamination

Question 26

What rise of Hb is expected with each unit of red cells transfused?

Answer 26

10g/L

Question 27

what is the blood volume?

Answer 27

70ml/kg

Question 28

How long does normal sending for compatible blood take?

Answer 28

an hour

Question 29

Is cross-matching needed for platelet transufsion?

Answer 29

no

Question 30

what is the threshold for platelet transfusion?

Answer 30

10x10^9/L

Question 31

What would cause the threshold for platelet transfusion to go up?

Answer 31

if patient has fever as platelet survival is shorter with infection; or bleeding; or bruising;

Question 32

What is the commonest indication for FFP?

Answer 32

correct coag deficiency in patient with liver disease who are bleeding

Question 33

What are the indications for FFP?

Answer 33

bleeding or surgery in liver disease with impaired coag; coagulopathy following transfusion; DIC

Question 34

What happpens in immediate haemolytic transfusion reaction?

Answer 34

anti-ABO antibodies to wrong blood group transfusion bing and activate complemetn and rupture of the memrbane; this releases thromboplastins causing more complement and DIC; complement vasodilates

Question 35

What 3 systems are activated with an acute haemolytic tranfusion reaction?

Answer 35

kinin; complement and coagulation systems

Question 36

What are the net effects in acute haemolytic transfusion reaction

Answer 36

systemic hypotension; DIC; renal vasconstriction; renal intravascular thrombi; shock and renal failure

Question 37

What blood samples should be obtained with immediate haemolytic transfusion reaction?

Answer 37

blood to transfusion lab; blood cultures; FBC; coag screen; biochemistry; haptoglobin level

Question 38

What is the function of haptoglobin?

Answer 38

binds free Hb

Question 39

What are the features of an acute haemolytic reaction?

Answer 39

pyrexia/rigors; dizziness; tachy; hypotensive; pallor/sweating; HA/chest/lumbar pain; local pain at infusion; cyanosis

Question 40

What antibodies are usually implicated in delayed haemolytic transfusion reactions?

Answer 40

irregular antibodies

Question 41

What are the lab features of delayed haemolytic reactions?

Answer 41

anaemia; spherocytic red cells on blood film; elevated bilirubin and LDH; positive DAGT and/or red cell allo-antibody; renal failure

Question 42

What is the management of an immediate haemolytic transfusion reaction?

Answer 42

stop transfusion; start IV fluids; obtain blood samples

Question 43

What blood samples should be collected after an immediate haemolytic transfusion reaction?

Answer 43

transfusion lab; FBC and blood flim; coag screen; biochemistry; blood cultures and serum haptoglobin

Question 44

What are the features of a dleyaed haemolytic transfusion reaction?

Answer 44

symptoms similar but less acute than IHTR; unexplained fall in Hb; appearance of jaundice; renal failure of biochemical features; detection of positive DAGT or irregular antibodies in post-transfusion blood samples

Question 45

Why is complement not activated in delyaed haemolytic reactions?

Answer 45

most irregular antibodies do not activate complement

Question 46

Why is the lack of complement in delayed haemolytic reactions significant?

Answer 46

no intravascular red cell destruction but extravascular eg spleen

Question 47

why are there spherocytes with delayed haemolytic reaction?

Answer 47

when antibody coated RBCs go through spleen are destroyed by macrophages, but some excape back to circulation with damaged cell membrane--shape changes

Question 48

What is a postiive direct antiglobulin test?

Answer 48

addition of anti-human globulin to sensitised red cells to look for agglutination

Question 49

What causes febrile non-haemolytic transfusion reactions?

Answer 49

recipient has anti-HLA antibodies that bind to residual white cells within the component being transfused or vasoactive and pyrogenic substances being released from WBCs during storage

Question 50

What are the features of febrile non-haemolytic transfusion reaction?

Answer 50

rapid temperature rise 1-2 degrees; chills; rigors

Question 51

What is the prevention of febrile non-haemolytic transfusion reactions?

Answer 51

anti-pyretics and leucodepleted blood components

Question 52

What is an urticarial reaction to blood products?

Answer 52

mast cell IgE response to infused plasma proteins resulting in rash/weals within few minutes of starting transfusion

Question 53

What is the management of urticarial reaction to trasnfusion?

Answer 53

slow transfusion and consider anti-histamines

Question 54

What is the management of severe urticarial reactions?

Answer 54

need to wash blood components of all residual plasma and suspend cells in plasma

Question 55

What are the symptoms of bacterial infection of transfusion?

Answer 55

fever; immediate collapse; shock ; DIC

Question 56

What bacteria are associated with red cells?

Answer 56

pseudomonas; yersinia

Question 57

What bacteria are associated with platelets?

Answer 57

staph, strep, serratia, salmonellae

Question 58

What is the chance of blood components infecting a patietn with hIv?

Answer 58

1 in 6 million chance