Flashcards in Haematology 14 - Blood Transfusion 1 & 2 Deck (54)
Recall 2 ways in which patients' blood group is tested
1. Using anti-A,B and O reagents against the patient's red blood cells
2. 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?
1. Optomise haematopoiesis
2. Reduce bleeding (eg stop anti-platelt drugs, cell-salvage techniques)
3. 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
In what type of surgery is post-operative cell salvage most often done?
What are the steps of intra-operative cell salvage?
Centrifuge, filter, wash and re-infuse blood
What special blood reuquirements do pregnant women have?
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?
Recall the 10 classes of transfusion reaction, and which are acute/ delayed?
Acute (<24 hours):
1. Acute haemolytic (ABO incompatible)
2. Allergic/ anaphylaxis
3. Bacterial infection
4. Febrile non-haemolytic
6. Delayed haemolytic transfusion reaction (antibodies)
7. Transfusion-associated GVHD
8. Infection (malaria, CJD)
9. Post-transfusion purpura
10. Iron overload (thalasaemia patients mostly)
What monitoring should be done during a blood transfusion as minimum?
1. Baseline temp, HR, RR, BP
2. Repeat obs after 15 mins
3. 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
What is the pathophysiology of febrile non-haemolytic transfusion reaction?
Cytokines released by white blood cells during storage cause a febrile reaction upon transfusion
What should be the management of an allergic transfusion reaction?
Stop/ slow transfusion
What are the symptoms of ABO incompatibility?
Shock and fever
Restlessness, fever, vomiting and collapse
What is the appropriate management for ABO incompatibility?
Check patient and component
Repeat cross match and DAT
What are the symptoms of bacterial contamination of blood?
Presents very similar to wrong blood - shock, increased temp, restless, fever, vomiting, collapse
How does bacterial contamination of blood cause symptoms?
Bacterial growth --> endotoxin which causes immediate collapse
Recall some protocols for prevention of bacterial contamination of blood
Diversion of first 20mls of blood
Which patients are at most risk of anaphylactic reaction to a blood transfusion?
Those with IgA deficiency