Blood Transfusion Flashcards
Why should you be careful prescribing blood products?
- 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
What is the NICE recommendations on threshold of when to use red blood cell transfusion?
- 70g/L without any major haemorrhage or ACS
- Then target Hb of 70-90g/L after transfusion
Two important blood groups
- ABO
- Group D of rhesus system
What is RhD +?
- 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
Universal donor vs universal acceptor
- Donor = O-ve - anyone can have this blood
- Acceptor - AB+ve - give this person ANY donor blood
What is group and save?
- 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
What is crossmatch?
- 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
When should cytomegalovirus blood be given?
- Women during pregnancy
- Intrauterine infusions
- Neonates (up to 28 days)
As it may cause sensorineural deafness and cerebral palsy if congenital infection
What are irradiated blood products?
- Reduce risk of graft vs host disease
Who should have irradiated blood products?
- 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
Observation intervals when administering blood products
- Before transfusion starts
- 15-20 mins after starting
- At 1hr
- At completion
Cannulas for blood products
- Green (18G) or grey (16G) cannula only
- Due to risk of cells haemolysing through narrow tube
Blood vs fluid giving set
- Blood giving set has filter within chamber
- Fluid giving set does not
Types of blood products
- Packed red cells
- Platelets
- Fresh frozen plasma
- Cryoprecipitate
When are packed red cells given?
- Acute blood loss
- Chronic anaemia where Hb 70g/L or less (or 100g/L or less in CVD)
- Symptomatic anaemia
How much should 1 unit of packed red cells increase Hb by?
10g/L
Indications for platelet tranfusion
- Haemorrhagic shock in trauma patient
- Profound thrombocytpenia (<20 x10^9/L)
- Bleeding + thrombocytopenia
- Pre-op platelet level <50 x 10^9/L
What is in FFP?
Clotting factors
Indications for FFP
- DIC
- Any haemorrhage secondary to liver disease
- All massive haemorrhages (after 2nd unit of packed red cells usually)
What is in Cryoprecipitate?
- Fibrinogen
- vWF
- Factor VIII
- Fibronectin
Indications for cryoprecipitate
- DIC with fibrinogen <1g/L
- von Willebrands disease
- Massive haemorrhage