What are the criteria for critical bleeding or massive transfusion? (6)
- Blood loss >150ml/min
- Loss of 1.5ml/kg/min over 20 minutes
- > 3 x RC in any 1 hour period
- 50% TBV replaced over 3 hours
- > 4 x RC in any 4 hour period
- 1 TBV or 10 RC replaced over 24 hours
What are some of the principles of massive transfusion?
- use BALANCED products
- treat early and adequately
- plasma alone is insufficient to correct hypofibrinogenaemia
- 1:1:1 FFP, plt, RC
- TEG/ROTEM to individualise therapy
- goal-directed therapy
What are the goals of MTP?
- rapid control of bleeding
- prevent and minimise coagulopathy
- void unnecessary transfusion
- minimise end organ dysfunction
What is the expected incrementation after 1 unit of platelets?
20-40 x 10^9
In which conditions are platelet transfusio`ns contraindicated?
ITP
TTP
HIT unless life-threatening haemorrhage
What is in FFP? What are some of the indications?
whole blood or apheresis split into 2-3 units, contains all coagulation factors (200 IU VII and V)
- coagulopathy
- MTP
- CPB
- DIC
- warfarin overdise
- TTP
How is cryoprecipitate formed? What are the components?
Cold-insoluble precipitate at 1-6 degrees
FVIII, vWF, fibrinogen, FXIII, and fibronectin
Who gets CMV seronegative components?
Pregnant women
Intra-uterine infusions
Neonates
Granulocyte transfusions for CMV negative patients
Who gets leucodepleted prducts?
- solid organ transplants
- haematopoetic stem cell transplants
- haem onc patients
- immunodeficient patients
What are the 4 broad causes of transfusion complications?
Immunological (alloantibodies on recipient or donor side)
Infection (viral, bacterial, prion)
Administrative (ID, lab errors, transport)
Storage (degeneration, temperature)
Differentiate between acute and delayed presentations of immune transfusion reactions
ACUTE
- febrile non-haemolytic
- allergic
- haemolytic
- TRALI
DELAYED
- delayed haemolysis
- alloimmunisation
- GVHD
- post-transfusion purpura
What are the presenting features and mechanism of an ACUTE haemolytic transfusion reaction?
fevers/chills/rigors chest/flank pain shock Haemoglobinuria Bleeding
MECHANISM
- ABO incompatibility or other red cell antibodies
- Ab binds to RBC, activates complement leading to lysis or FBC
- Cytokines, activation of coagulation, fibrinolysis leading to shock, renal failure, coagulopathy and MOF
What are the presenting features and mechanism of a DELAYED haemolytic transfusion reaction?
Inadequate rise/fall in Hb 2-14 days post transfusion
Fever/Jaundice
Positive DAT
Previously formed RBC Ab not detected on pre-transfusion testing, transfused RBCs removed/destroyed
Differentiate between TACO and TRALI
What is the mechanism of TRALI?
BOTH: dyspnoea, hypoxia, white out XR
TRALI: Hypotension, no features of overload
TACO: hypertension, pleural effusions
- Neutrophils become primed/susceptible due to pre-existing conditions (trauma, ventilation)
- Plasma with leukocyte antibodies/biologic agents
- Transfusion leads to damage to endothelium, capillary leak and pulmonary oedema
What are the signs/symptoms of transfusion-associated GVHD and what is the mechanism?
1-2 weeks post transfusion Fever Rash Diarrhoea Hepatic dysfunction Progressive pancytopenia
Immunodeficient patient unable to recognise t lymphocytes in transfused product, lymphocytes engraft and destroy patient’s own cells
What are the laboratory findings of trauma induced coagulopathy?
Prolonged APTT/PT or INR >1.5x upper limit of normal with low fibrinogen in association with trauma
What are the 2 major driving factors of trauma-induced coagulopathy?
Hypocoagulable state driven by upregulation of thrombomodulin and APC
○ Decreased availability of Va and VIIIa
○ Decrease in PAI1 (regulator of fibrinolysis)
Hypoperfusion results in massive thrombin release, fibrin deposition, tPA locally and globally driving fibrinolysis
