Blood Transfusions + Major Haemorrhage Flashcards
What temperature are red cells stored at and for how long?
4 degrees for 35 days
What temperature is FFP stored at and for how long?
-30 degrees for 3 years
What temperature are platelets stored at and for how long?
22 degrees for 7 days (with agitation)
Which chromosome are the ABO genes found on?
Chromosome q
Which blood groups are dominant?
A + B are co-dominant over O (O is silent)
Which blood group is the universal donor?
O –> can be given to anyone
Which blood group is the universal reciever?
AB –> can receive blood from any other group
Which antigen on RBCs is next most important after ABO?
RhD
How is ABO/RhD grouping determined?
- Test patient’s red cells with anti-A, anti-B and anti-D
- direct agglutination - Test patient’s plasma against red cells of group A and group B
- -> define blood group - Antibody screening: patient’s plasma + red cells with a range of antigens
- indirect antiglobulin test (add anti-human Ig)
What are the indications for a red cell transfusion?
SYMPTOMATIC anaemia Hb < 70 (< 80 if cardiac disease)
Major bleeding
What are the indications for a platelet transfusion?
Prophylaxis in patients with bone marrow failure + very low platelets
Treatment of bleeding in thrombocytopenic patient
Prophylaxis prior to surgery in thrombocytopenic patient
What is the difference between platelets and FFP?
Platelets = primary homeostasis FFP = clotting factors from coagulation cascade = secondary homeostasis
What are the indications for FFP transfusion?
Treatment of bleeding or surgical prophylaxis in patient with coagulopathy (PT ratio > 1.5)
Management of massive haemorrhage
What are the symptoms and signs of an acute transfusion reaction?
Symptoms: - chills, rigors - rash, flushing - feeling of impending doom - collapse - loin pain - respiratory distress Signs: - fever - tachycardia - hypotension
What is the differential for an acute transfusion reaction?
Acute haemolytic transfusion reaction
Bacterial contamination of blood products
What are the principles of management for all acute transfusion reactions?
- STOP the transfusion
- Assess patient with ABCDE
- Re-check compatibility tag against patient details and inspect bag for evidence of contamination
- Document event in medical notes
What causes an acute haemolytic transfusion reaction?
ABO incompatible blood transfusion (most dangerous) or other antigen
Binding of IgM anti-A or anti-B to their corresponding antigens
–> intravascular haemolysis of transfused red cells + release of inflammatory cytokines
What are the features of an acute haemolytic transfusion reaction?
Shock Increased vascular permeability DIC Renal failure --> often fatal
Which type of blood product is most likely to contain bacterial contamination?
Platelets (stored at warmest temperature)
How should a suspected bacterial contamination transfusion reaction be managed?
Stop transfusion ABCDE Culture patient + remains of unit Broad spectrum antibiotics Need to inform transfusion lab so that other units can be quarantined
What are the features of transfusion related circulatory overload (TACO)?
Respiratory distress within 6 hours of transfusion
Raised BP and raised JVP
Positive fluid balance
What are the risk factors for TACO?
Elderly Cardiac failure Low albumin Renal impairment Fluid overload
How should a patient with TACO be managed?
Oxygen + diuretics
Slow rate of further transfusions
Only transfuse minimum volume required
–> identify patients at risk before transfusion
Give two examples of mild transfusion reactions?
Febrile non-haemolytic transfusion reaction
Mild allergic reaction
What are the features of a febrile non-haemolytic transfusion reaction?
Isolated temperature rise > 38 degrees or rise of 1-2 degrees
What are the features of a mild allergic transfusion reaction?
Rash/itch but normal observations
How should a mild transfusion reaction be managed?
Slow rate of transfusion
Close monitoring in case condition worsens
Consider paracetamol/anti-histamine
What is a delayed haemolytic transfusion reaction?
Extravascular haemolysis 5-10 days post-transfusion
How is a delayed haemolytic transfusion reaction diagnosed?
Drop in Hb
Rise in bilirubin
+ve DAT (direct Coombs’) + detection of allo-antibody
How is major haemorrhage defined?
Volume + rate of blood loss:
- one blood volume in 24 hours
- blood loss of 150ml/min
- obstetrics: major = >1000ml
Or by clinical situation:
- HR > 110 +/- systolic BP < 90
- bleeding which has already prompted use of emergency O neg red cells
What are the initial steps of the major haemorrhage protocol?
Call blood bank and state 'major haemorrhage' Send urgent blood samples: - FBC, coag, fibrinogen, crossmatch, U&Es, calcium Blood bank will issue: - 4 units red cells - 4 units FFP - 1 unit platelets Resus --> ABCDE
What should be done if there is ongoing bleeding following the initial steps of the major haemorrhage protocol?
Repeat blood samples
Transfuse further RBCs + FFP at rate of 2:1 (1:1 in trauma)
Cryoprecipitate if fibrinogen < 1
Consider further platelets
What does cryoprecipitate do?
Replaces fibrinogen
Which bleeding situations have specific management protocols?
Post partum haemorrhage
Trauma
Variceal bleed
Ruptured AAA
