Trauma! Massive Transfusion

The simplest trigger is when a senior clinician suspects impending or actual hemorrhagic shock in bleeding patient.

Various scoring systems have been developed to predict the need for massive transfusion, such as the ABC score, the TASH score and the McLaughlin score

Show scoring systems

There is also research that methods such as thromboelastometry can give an early warning of acute coagulopathy of trauma/ shock (ACoTS).

Learn more:

• Resus.ME — Predicting massive transfusion (thromboelastometry)

Definitions vary… They include:

• 10 unit transfusion in 24 h
• transfusion of an entire blood volume in 24 h
• replacement of 50% blood volume over 3 h

Up to 5% of civilian trauma patients require massive transfusion, and of these 25% have trauma-associated coagulopathy on assessment in ED.

• Age, gender, mechanism of injury
• Blood components given pre-hospital
• FFP and platelets are likely to be needed earlier if the patient has been transfused pre-hospital
• Known bleeding diathesis
• Bleeding disorders and coagulopathies
• Drugs, e.g. warfarin, aspirin and clopidogrel
• History of previous transfusions, antibodies, reactions if known

Administer a 1:1:1 ratio of red cells, FFP and platelets

This ratio of blood products emulates the composition of whole blood. The target is to achieve 1:1:1 ratio over 6 hours.

The protocol I’m most familiar with involves:

• Activation of massive transfusion protocol (includes alerting the hematologist on call and laboratory staff)
• Send blood tests: cross match, coags, FBC, blood gas (including iCa)
• Give initial major hemorrhage pack (4 units PRBCS and 2 units thawed FFP)
• In the presence of ongoing uncontrolled haemorrhage give alternating packs A and B, with repeat blood tests after each pack:
  — Pack A: 2 units PRBC, 2 units FFP, 1 adult bag of platelets
  — Pack B: 2 units PRBC, 2 units FFP

Note that 1 adult bag of platelets is equivalent to 4 units PRBCs for the purposes of maintaining the 1:1 ratio.

Note that the 1:1:1 concept is mainly supported by the fact that it makes sense pathophysiologically and by retrospective and observational studies. It has not been conclusively proven in the way that a large double-blind randomised controlled trial would. Indeed, there are concerns that at least some of the perceived benefit of hemostatic resuscitation and the ’1:1:1′ ratio is due to survivor bias. Cliff Reid states this eloquently:

“In some circles, ‘wuntwuntwun’ is in danger of becoming the new dogma of trauma fluid replacement (ie. 1 unit of plasma and 1 unit of platelets for every unit of red cells). Since it takes longer to thaw some plasma than it does to throw in some O negative packed red cells, some really sick patients may be dead before they get the plasma, biasing comparisons that show a reduced mortality in patients who were still alive to receive plasma. This ‘survivor bias’ has been suggested as a reason that high plasma:red cell ratios are associated with mortality reduction, although this has been challenged.”

Learn more:

• Broome Docs — Managing Traumatic bleeding: how can we apply the evidence in smaller hospitals?
• EMCrit Lecture: Haemostatic Resuscitation by Richard Dutton
• EMCrit Podcast 30 – Haemorrhagic Shock Resuscitation
• Resus.ME — Battlefield Resuscitation
• Resus.Me — Plasma: Red cell ratios (survivor bias)

Current Australian guidelines advise that tranexamic acid should be considered in trauma patients with, or at risk of, significant haemorrhage.

Tranexamic acid an antifibrinolytic that works by competitively inhibiting the activation of plasminogen to plasmin  plasmin is responsible for the degradation of fibrin. Given that tranexamic acid is cheap, one of the few interventions with proven mortality benefit (NNT = 67) and few adverse effects I think clinicians should strongly consider this using this agent in major trauma patients.

Tranexamic acid is given as 1g IV loading dose followed by 1g over 8 hours. It should be given with 3 hours of major trauma.

Tranexamic acid should be given early, within 3 hours of the time of injury.

Learn more:

• EMCrit Podcast 67 – Tranexamic Acid (TXA), Crash 2, & Pragmatism with Tim Coats
• Emergency Medicine Literature of Note — Critique of Crash-2
• Emergency Medicine Ireland — Crash-2
• ICU Rounds Podcast — EARLY use of Tranexamic Acid may improve survival from bleeding in trauma
• Resus.ME — How about pre-hospital tranexamic acid?
• Resus.ME — Tranexamic acid saves lives in trauma
• The Lancet — Crash-2: Tranexamic Acid and Trauma Patients (includes link to fulltext pdf)
• The NNT — Tranexamic acid for Trauma

Again, based on the protocol with which I am most familiar:

Platelets

• Give platelets 1 adult dose if platelets <50 x 10E9/L

FFP

• Give FFP 4 units if INR > 1.5 or APTT >50

Cryoprecipitate

• Give cryoprecipitate 8 units if fibrinogen <1.o g/L

Calcium

• Give 10% calcium chloride 10 mL if ionized calcium <1.1 mmol/L

The main difference in the Australian National Blood Authority guidelines is that FFP 15 mL/kg is recommended rather than 4 units.

Recombinant Factor VIIa may be considered for use in consultation with a hematologist if there is:

• Uncontrolled haemorrhage
• That is not amenable to surgical or interventional radiological therapies
• In a salvageable patient with
  — optimal blood component therapy (INR, APTT, platelets and fibrinogen all in the normal range),
  — pH 7.2, and
  — normothermia (T>34C)

Factor VIIa is dosed at 100 mcg/kg to the nearest vial. Further blood component therapy can be given according to serial blood test results.

Remember that Factor VIIa is very expensive and has not been proven to affect clinically meaningful outcomes in the setting of major haemorrhage.

Learn more:

• LITFL — Hematology Hoodwinker 002: Recombinant Factor VIIa to the Rescue?!