Haematology 9 - Blood transfusion 1

Question 1

What is blood group determined by?

Answer 1

The RBC antigens and the IgM antibodies in the plasma

Question 2

Which type of immunoglobulin are anti-D antibodies?

Answer 2

igG (ABO antibodies are IgM)

Question 3

What is the significance of anti-D antibodies being IgG?

Answer 3

They do not cause intravascular haemolysis but instead cause delayed haemolytic transfusion reaction (Extravascular haemolysis)

Question 4

Difference between group and screen and cross match

Answer 4

In group and screen you check patient’s plasma antibodies and ABO blood group by using known anti-A ant anti-B reagents against patient’s RBCs. In cross match you check the patient’s blood against the donor blood directly

Question 5

Which kind of Coomb’s test does cross matching involve?I

Answer 5

IAT (indirect antiglobulin technique)

Question 6

Which other antibodies can cause delayed haemolytic transfusion reaction?

Answer 6

Kell and Duffy

Question 7

Which blood component is most prone to bacterial contamination?

Answer 7

Platelets because they are stored at room temp

Question 8

Storage and infusion time of RBCs

Answer 8

4C for 35 days, infusion time of 1 unit of 2-3 hours

Question 9

Storage and Infusion time of platelets

Answer 9

room temp 7 days, 20-30 minutes

Question 10

Storage and infusion time of plasma

Answer 10

Frozen, 20-30 minutes

Question 11

Universal donor for platelets

Answer 11

AB group as have no antibodies

Question 12

Increase in hb fo reach unit of transfusion = ?

Answer 12

10g/L

Question 13

Method of autologous blood transfusion available in UK

Answer 13

Cell salvage either intraoperatively or post-operatively

Question 14

Contraindications to platelet transfusion

Answer 14

Heparin induced thrombocytopenia and thrombosis

TTP

Question 15

FFP indications for transfusion

Answer 15

DIC with bleeding as it contains all the clotting factors

Question 16

The transfusion of choice for warfarin reversal

Answer 16

Prothrombin complex concentrate (contains factors 2,7,9,10)

Question 17

Which transfusion products are not cross matched

Answer 17

Platelets and FFP but right group should be selected

Question 18

Two ways in which red cells can be cross matched

Answer 18

Serologically or electronically

Question 19

Most common blood group in UK

Answer 19

Blood group O, specifically O+

Question 20

Main reason for giving cryoprecipitate

Answer 20

Contains fibrinogen

Question 21

Main components in cryoprecipitate

Answer 21

Fibrinogen, fibronectin, factor VIII, vWF, factor XIII

Question 22

Below what level of hb do we tend to transfuse?

Answer 22

~70-90g/L (<70 if asymptomatic, <80 if symptomatic, threshold around 90-100 in pts with coronary complications)