Blood Transfusion

Question 1

Why should you be careful prescribing blood products?

Answer 1

• Transfusion reactions common - even in those with cross-matched blood
• Blood products are scarce - only use when necessary
• Incompatibility is rare but life threatening - need crossmatching and checking to avoid severe consequences

Question 2

What is the NICE recommendations on threshold of when to use red blood cell transfusion?

Answer 2

• 70g/L without any major haemorrhage or ACS
• Then target Hb of 70-90g/L after transfusion

Question 3

Two important blood groups

Answer 3

• ABO
• Group D of rhesus system

Question 4

What is RhD +?

Answer 4

• Rhesus surface antigens on RBC
• If someone who is RhD- is given RhD+ blood - makes anti-D (or if gives birth to RhD+ baby)
• But this won’t attack own blood as it is RhD-
• BUT this becomes a problem during pregnancy as they can cross placenta
• If have RhD+ foetus = haemolytic disease of newborn

Question 5

Universal donor vs universal acceptor

Answer 5

• Donor = O-ve - anyone can have this blood
• Acceptor - AB+ve - give this person ANY donor blood

Question 6

What is group and save?

Answer 6

• Determines patients blood group - ABO and RhD status
• Screens blood for any atypical antibodies
• Takes around 40mins but issues NO blood
• Use if blood loss not anticipated but blood may be needed if more than expected

Question 7

What is crossmatch?

Answer 7

• Physically mixing patients blood with donors blood - check to see if immunological reaction
• This takes around 40 mins + 40 mins for G&S (as this must be done 1st)
• Crossmatch done if blood loss is anticipated

Question 8

When should cytomegalovirus blood be given?

Answer 8

• Women during pregnancy
• Intrauterine infusions
• Neonates (up to 28 days)

As it may cause sensorineural deafness and cerebral palsy if congenital infection

Question 9

What are irradiated blood products?

Answer 9

• Reduce risk of graft vs host disease

Question 10

Who should have irradiated blood products?

Answer 10

• Receiving blood from first or second degree family members
• Hodgkins lymphoma patients
• Recent haemopoetic stem cell transplant
• After anti-thymocyte globulin or Alemtuzumab therapy
• Those receiving purine analogues as chemotherapy
• Intrauterine infusions

Question 11

Observation intervals when administering blood products

Answer 11

• Before transfusion starts
• 15-20 mins after starting
• At 1hr
• At completion

Question 12

Cannulas for blood products

Answer 12

• Green (18G) or grey (16G) cannula only
• Due to risk of cells haemolysing through narrow tube

Question 13

Blood vs fluid giving set

Answer 13

• Blood giving set has filter within chamber
• Fluid giving set does not

Question 14

Types of blood products

Answer 14

• Packed red cells
• Platelets
• Fresh frozen plasma
• Cryoprecipitate

Question 15

When are packed red cells given?

Answer 15

• Acute blood loss
• Chronic anaemia where Hb 70g/L or less (or 100g/L or less in CVD)
• Symptomatic anaemia

Question 16

How much should 1 unit of packed red cells increase Hb by?

Answer 16

10g/L

Question 17

Indications for platelet tranfusion

Answer 17

• Haemorrhagic shock in trauma patient
• Profound thrombocytpenia (<20 x10^9/L)
• Bleeding + thrombocytopenia
• Pre-op platelet level <50 x 10^9/L

Question 18

What is in FFP?

Answer 18

Clotting factors

Question 19

Indications for FFP

Answer 19

• DIC
• Any haemorrhage secondary to liver disease
• All massive haemorrhages (after 2nd unit of packed red cells usually)

Question 20

What is in Cryoprecipitate?

Answer 20

• Fibrinogen
• vWF
• Factor VIII
• Fibronectin

Question 21

Indications for cryoprecipitate

Answer 21

• DIC with fibrinogen <1g/L
• von Willebrands disease
• Massive haemorrhage