Haematology 14 - Blood Transfusion 1 & 2 Flashcards
Recall 2 ways in which patients’ blood group is tested
- Using anti-A,B and O reagents against the patient’s red blood cells
- Also use ‘reverse group’ - known A and B group RBCs against the patient’s plasma
Describe the process of antibody testing of blood
Group and screen
- Use 2 or 3 reagent red blood cells containing all the important RBC antigens between them
- Then incubate the patient’s plasma using the indirect antiglobulin technique
What is the purpose of ‘immediate spin’ blood testing?
Used in emergencies only
Incubation for just 5 minutes
Determines ABO compatibility only
What are the 3 pillars of patient blood management?
- Optomise haematopoiesis
- Reduce bleeding (eg stop anti-platelt drugs, cell-salvage techniques)
- Harness and optomise physiological tolerance of anaemia
For which blood products is D compatibility required?
Red cells and platelets (but not FFP or cryoprecipitate)
What is the storage temperature of red cells, platelets, FFP and cryoprecipitate?
Red cells: 4 degrees C
Platelets: 20 degrees C
FFP: 4 degrees C once thawed
Cryoprecipitate: Room temp once thawed
What is the storage length of red cells, platelets, FFP and cryoprecipitate?
Red cells: 35 days
Platelets: 7 days
FFP: 24 hours
Cryoprecipitate: 4 hours
What is the transfusion rate of red cells, platelets, FFP and cryoprecipitate?
Red cells: 1 unit over 2-3 hours
Platelets: 1 unit over 20-30 mins
FFP: 1 unit over 20-30 mins
Cryoprecipitate: 1 unit over 20-30 mins
How much blood loss counts as ‘major’?
> 30% blood volume lost
When are platelets contra-indicated?
TTP/ heparin-induced TTP
How low does haemaglobin need to be to require transfusion peri-operatively vs post-chemo?
Peri-op/ crit care: <70g/dL
Post-chemo: <80g/dL
In what type of surgery is post-operative cell salvage most often done?
Knee surgery
What are the steps of intra-operative cell salvage?
Centrifuge, filter, wash and re-infuse blood
What special blood reuquirements do pregnant women have?
CMV neg
What special blood reuquirements do highly immunocompromised patients have?
Blood needs to be irradiated
What special blood requirements do patients who have had severe reactions in the past to transfusion have?
Washed cells
Recall the 10 classes of transfusion reaction, and which are acute/ delayed?
Acute (<24 hours):
- Acute haemolytic (ABO incompatible)
- Allergic/ anaphylaxis
- Bacterial infection
- Febrile non-haemolytic
- TACO/TRALI
Delayed:
- Delayed haemolytic transfusion reaction (antibodies)
- Transfusion-associated GVHD
- Infection (malaria, CJD)
- Post-transfusion purpura
- Iron overload (thalasaemia patients mostly)
What monitoring should be done during a blood transfusion as minimum?
- Baseline temp, HR, RR, BP
- Repeat obs after 15 mins
- Repeat hourly after end of transfusion
What are the features of febrile non-haemolytic transfusion reaction?
Temp increase >1%
Chills and rigors
Why is febrile non-haemolytic transfusion reaction rare nowadays?
Blood is now leucodepleted to reduce risk of febrile non-haemolytic transfusion reaction
How should febrile non-haemolytic transfusion reaction be managed?
Stop/ slow the transfusion and give paracetamol