2015 47 Blood Transfusion

Question 1

** What are the definitions of anemia in each stage of pregnancy? **

Answer 1

1st trimester: < 110
2nd & 3rd: < 105
Postpartum: < 100

Question 2

** When should anaemia be screened for in pregnancy? **

Answer 2

Booking
28/40
Extra at 20-24/40 in multiple pregnancy

Question 3

** When should blood group & antibodies be checked in pregnancy? How long do samples last? **

Answer 3

Booking
28/40
Weekly in high risk eg placenta praevia

Samples last 3 days

Question 4

** Which compatabilities are needed in blood transfusion? **

Answer 4

ABO
RhD
K
Clinically significant red cell antibodies

Question 5

** What precautions need to be taken in cell salvage for Rh negative women? **

Answer 5

Administer 1500 units anti-D
Test for FMH 30-40 mins later to guide further anti-D

Question 6

** In what circumstances should FFP & cryoprecipitate be used? **

Answer 6

FFP: 12-15mg/kg
For every 6 units of red cells
Aim to maintain PT & APTT < 1.5 x normal

Cryoprecipitate: 2 x 5-unit pools
Aiming for fibrinogen > 1.5

Question 7

** What are the triggers for platelet transfusion? **

Answer 7

50 is critical level for haemostasis
Trigger of 75 for margin of safety
Should be group & RhD compatible

Question 8

** What pharmacological can be used in major obstetric haemorrhage? **

Answer 8

1. Consider TXA
2. Recombinant factor VIIa if life-threatening, but don’t delay procedures
3. Not fibrinogen concentrate

Question 9

** What is the trigger for red cell transfusion? **

Answer 9

< 70
Dependent on medical hx & Sx
Almost always needed <60, almost never >100

Question 10

What is the epidemiology of severe obstetric haemorrhage in the UK?

Answer 10

1. 3rd leading direct cause of maternal death
2. 10% of direct deaths
3. > 4000 cases a year

Question 11

What impact does iron +/- folic acid have in late pregnancy?

Answer 11

1. 50% reduction in anaemia
2. Decreased incidence SGA babies

Question 12

What impact do drinks have on iron absorption?

Answer 12

Vitamin C enhances
Tea & coffee inhibit

Question 13

How does e-issuing work?

Answer 13

1. ABO & Rh compatible
2. No cross-matching needed
3. No need to reserve units
4. If no additional antibodies

Question 14

What effect can maternal red cell antibodies have?

Answer 14

1. Haemolytic disease of fetus & newborn
2. Maternal haemolytic transfusion reactions

Question 15

What is the normal threshold for considering cell salvage?

Answer 15

Anticipating 20% + blood volume loss

Question 16

What dose of anti-D should be used if Rh positive platelets are given to a Rh -ve woman of childbearing age?

Answer 16

250 units

Question 17

What do TEG & ROTEM stand for?

Answer 17

Thromboelastography
Rotation thromboelastography

Question 18

How does tranexamic acid work?

Answer 18

Synthetic derivative of lysine
Binds to lysine binding sites of plasminogen molecule
So prevents activation of plasminogen to plasmin
So inhibits fibrinolysis