Mass Transfusion Protocol

There are two main definitions used:

• Austin guideline: the transfusion of 50% blood volume in 4 hours, or >1 blood volume in 24 hours (blood volume is approx. 70mL/kg).
  • Which is going to be approx. 8 units per 4 hours, or 16 units per 24 hours
  • Activate the protocol when you anticipate >4 units required, or when 4 have been transfused in 4 hours and more is required.
• ATLS defines adult MTP as 4 units in one hour or 10 units in 24 hours

Goals

• Maintain tissue perfusion and oxygenation
• Prevent trauma-induced or resuscitation-induced coagulopathy
• Aggressive control of bleeding

Pathophysiology of coagulopathy in trauma

• Acute trauma - endogenous process whereby injury and hypoperfusion lead to acidosis, impairing coagulation cascade
• Resuscitation - unbalanced resus dilutes/does not replace clotting factors
• 'Trauma-induced coagulopathy' has been defined as acute traumatic and resuscitation-induced coagulopathy combined

Epidemiology

• In trauma, risk is high in these patients:
  • SBP <70
  • HR >110 and SBP <90
  • Penetrating injury or major fractures
  • Fluid in body cavities likely to be blood

Process:

• Contact blood bank on 4630 (at Austin)
• Designate one person as liaison who will provide basic information to lab
• Pre-transfusion sample collected and sent
• pRBC and platelets take about 5 minutes, while FFP/cryo takes 30 mins
• Ratio
  • The common phrase is '1:1:1' but really what they mean is 4 units RBC, 4 units FFP and 1 bag of pooled platelets (which is somehow equivalent to 4 units)
    • 2024 update to Austin guidelines states 8 units pRBC : 1 bag pooled platelets = 4 units platelets : 4 bags FFP
  • Give first bag FFP after 4 units of RBC have gone in
• FBE and coags every 30 mins
• Consider tranexamic acid (1g IV over 10 mins followed by 1g over 8 hours) - best evidence if given within 3 hours; worth giving up to 8 hours
• Recombinant factor VIIa can be considered as last resort in ongoing bleeding

Complications:

• Hypocalcaemia
  • Citrate is present in blood products, which chelates calcium
  • Can lead to coagulopathy
  • Calcium will need to be replaced
• Hyperkalaemia
• Acidosis
• Standard transfusion complications

Blood products

• Packed red blood cells
  • Red cell component after centrifuging to remove platelets and most plasma
  • Additives SAG-M: saline, adenine, glucose, mannitol
  • Volume 260mL
  • Storage temp 2-6 degrees
  • Shelf life 42 days
• Platelets
  • Platelets obtained from a group of ABO-identical donors, with leucocytes removed
  • Additives: citrate, phosphate, acetate, potassium, magnesium
  • Volume 367mL, which is equivalent to about 20-40 change in serum platelets
  • Storage temp 20-24 degrees
  • Shelf life 5 days
• Fresh frozen plasma
  • Made up of plasma collected via apheresis or separated from whole blood
  • Contains all coagulation factors
  • No additives
  • Volume about 270mL
  • Storage temp <-25deg
  • Shelf life 12 months frozen, then 2-6 degrees for 5 days
• Cryoprecipitate
  • Contains factors VIII and XIII, fibrinogen, fibronectin
  • No additives
  • Volume 36mL
  • Dose 1 unit per 5-10kg, to increase Fib by 0.5-1.0g/L
  • Storage temp <-25 degrees
  • Shelf life 12 months frozen
• Request times
  • pRBC, platelets and generic FFP take 5-10 minutes to prepare
  • Group-specific FFP and cryoprecipitate take 30 minutes to thaw