Blood Products Flashcards
What is the haemoglobin concentration threshold for red blood cell transfusion?
<70g/L
Target of 70-90g/L after transfusion
Describe the Rhesus D group.
Presence or absence of Rhesus D surface antigens on the red blood cells
80% of population is RhD+ (have antigens present)
When is it important to consider the Rhesus group and why?
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.
What is the universal donor?
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
What is the universal acceptor?
AB+ve
Recipient does not have any A, B or Rhesus antibodies so cannot mount immune response to blood
If you have A blood type what antibodies/antigens do you have and what blood types are compatible?
A antigen on red blood cells
Anti-B antibodies
A and O compatible
If you have B blood type what antibodies/antigens do you have and what blood types are compatible?
B antigen on red blood cells
Anti-A antibody
B and O compatible
If you have AB blood type what antibodies/antigens do you have and what blood types are compatible?
A and B antigens on red blood cells
No antibodies
A, B, AB, O compatible
If you have O blood type what antibodies/antigens do you have and what blood types are compatible?
No antigens on red blood cells
Anti-A and anti-B antibodies
O compatible
What is the difference between group and save and crossmatch?
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
Describe the process for requesting bloods.
3 points of ID - name, DOB, pt number
Consent - transfusion request form
Label bottle at bedside
What is it important to check for in blood for women who are pregnant?
Cytomegalovirus - congenital infection that may lead to sensorineural deafness/cerebral palsy
CMV negative blood should be given to pregnant women, intrauterine transfusion and neonates
When should obesrvations be carried out during transfusion?
Before it starys
15-20 mins after started
At 1 hour
At completion
What cannulas should be used for administering blood products?
Green (18G) or Grey (16G) cannula
otherwise cells haemolyse due to sheering forces
What are the types of blood products?
Packed red cells
Platelets
Fresh frozen plasma
Cryoprecipitate
What are the major constituents, indications and administration duration for packed red cells?
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
How much does 1 unit of blood increase Hb? What is it important to do after giving red cells?
10g/L
New G&S as patient blood cells may produce autoantibodies to donor surface antigens
What are the major constituents, indications and administration duration for platelets?
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
How much does 1 adult therapeutic dose of platelets increase platelet level by?
20-40x10^9/L
What are the major constituents, indications and administration duration for FFP?
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
What are the major constituents, indications and administration duration for cryoprecipitate?
Fibrinogen, von Willebrands Factor, Factor VIII and fibronectin 1. DIC with fibrinogen <1g/L 2. von Willebrand's Disease 3. Massive haemorrhage Duration: Stat
