Blood Products

Question 1

What is the haemoglobin concentration threshold for red blood cell transfusion?

Answer 1

<70g/L

Target of 70-90g/L after transfusion

Question 2

Describe the Rhesus D group.

Answer 2

Presence or absence of Rhesus D surface antigens on the red blood cells
80% of population is RhD+ (have antigens present)

Question 3

When is it important to consider the Rhesus group and why?

Answer 3

In women
RhD- woman will make antibodies to theRhD antigens if given RhD+ blood.
This does not matter for the patient as the anti-D antibodies cannot then go on to attack the woman’s own RBCs as they do not have the RhD antigen.
Anti-D antibodies can hover cross the placenta during pregnancy.
So if a woman becomes pregnant with a fetus that is RhD+, she may come into contact with foetal RhD+ blood in childbirth and develop antibodies to it.
Later, when pregnant with a second child, the woman anti–D antibodies will cross the placenta and enter the fetal circulation which contains RhD+ blood. This will cause the immune system to attack and destroy its own RBCs leading to foetal anaemia - haemolytic disease of the newborn.

Question 4

What is the universal donor?

Answer 4

O -ve (RhD negative)
Can be given to anybody as there are no A or B or Rhesus antigens on the donor RBC surface membrane.
Recipient can have bone A, B and Rhesus antibodies but they will not reject O-ve blood as there are no ABO or Rh antigens to attack

Question 5

What is the universal acceptor?

Answer 5

AB+ve

Recipient does not have any A, B or Rhesus antibodies so cannot mount immune response to blood

Question 6

If you have A blood type what antibodies/antigens do you have and what blood types are compatible?

Answer 6

A antigen on red blood cells
Anti-B antibodies
A and O compatible

Question 7

If you have B blood type what antibodies/antigens do you have and what blood types are compatible?

Answer 7

B antigen on red blood cells
Anti-A antibody
B and O compatible

Question 8

If you have AB blood type what antibodies/antigens do you have and what blood types are compatible?

Answer 8

A and B antigens on red blood cells
No antibodies
A, B, AB, O compatible

Question 9

If you have O blood type what antibodies/antigens do you have and what blood types are compatible?

Answer 9

No antigens on red blood cells
Anti-A and anti-B antibodies
O compatible

Question 10

What is the difference between group and save and crossmatch?

Answer 10

G&S determines patients blood group and screens for any atypical antibodies (40mins) no blood issued - recommended if blood loss is not anticipated but blood may be required if more loss than expected

X-match - physically mixing the patient’s blood with donor blood to see if there is any immune reaction taking place. 40 minutes + 40 mins for G&S.
Done if blood loss is anticipated

Question 11

Describe the process for requesting bloods.

Answer 11

3 points of ID - name, DOB, pt number
Consent - transfusion request form
Label bottle at bedside

Question 12

What is it important to check for in blood for women who are pregnant?

Answer 12

Cytomegalovirus - congenital infection that may lead to sensorineural deafness/cerebral palsy
CMV negative blood should be given to pregnant women, intrauterine transfusion and neonates

Question 13

When should obesrvations be carried out during transfusion?

Answer 13

Before it starys
15-20 mins after started
At 1 hour
At completion

Question 14

What cannulas should be used for administering blood products?

Answer 14

Green (18G) or Grey (16G) cannula

otherwise cells haemolyse due to sheering forces

Question 15

What are the types of blood products?

Answer 15

Packed red cells
Platelets
Fresh frozen plasma
Cryoprecipitate

Question 16

What are the major constituents, indications and administration duration for packed red cells?

Answer 16

RBCs
1. Acute blood loss
2. Chronic anaemia where Hb <70g/L or <100g/L in CVS disease or symptomatic anaemia
Duration: 2-4 hours

Question 17

How much does 1 unit of blood increase Hb? What is it important to do after giving red cells?

Answer 17

10g/L

New G&S as patient blood cells may produce autoantibodies to donor surface antigens

Question 18

What are the major constituents, indications and administration duration for platelets?

Answer 18

Platelets
1. Haemorrhagic shock in trauma patient
2. Profound thrombocytopenia (<20x10^9/L - normal range 150-400)
3. Bleeding with thrombocytopenia
4. Pre-operative platelet level < 50x10^9/L
Duration: 30 mins

Question 19

How much does 1 adult therapeutic dose of platelets increase platelet level by?

Answer 19

20-40x10^9/L

Question 20

What are the major constituents, indications and administration duration for FFP?

Answer 20

Clotting factors
1. Disseminated Intravascular Coagulation (DIC)
2. Any haemorrhage secondary to liver disease
3. All massive haemorrhages (after 2nd unit of packed red cells)
Duration: 30 minutes

Question 21

What are the major constituents, indications and administration duration for cryoprecipitate?

Answer 21

Fibrinogen, von Willebrands Factor, Factor VIII and fibronectin
1. DIC with fibrinogen <1g/L
2. von Willebrand's Disease
3. Massive haemorrhage
Duration: Stat