MTP: Fill ‘er Up – Part 1

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When to pull the trigger on your Massive Transfusion Protocol.

EMS calls with a trauma activation at 0130 for a 46-year-old male who fell asleep on the train tracks. He suffered amputations at the mid-humeral level and the right leg above the knee. EMS placed tourniquets high and tight on the right extremities, but the patient’s vital signs are BP 60/palp, HR 142, Sats 94% on 2L. Not only does this patient require resuscitation and an OR, but he needs a significant number of blood products.


What if EMS brings in a 25-year-old female at 27 weeks gestation with severe lower abdominal pain, bright red vaginal bleeding, and similar vital signs? What do you need to consider? Is the transfusion strategy different?

This article is the first of a two-part series evaluating massive transfusion protocol (MTP). Part 1 will investigate what comprises the products of MTP and when MTP should be activated (including scoring systems). Part 2 looks at implementation, conducting MTP, adjunctive agents, monitoring MTP patient and when to terminate MTP.

Hemorrhage is the major cause of morbidity and mortality in trauma, accounting for up to 50% of deaths in combination with coagulopathy, especially in the acute stage.1-3 Coagulopathy increases this mortality further and may be present in up to 40% of patients upon arrival as a part of the lethal triad (hypothermia, coagulopathy and acidosis).4,5


Damage control resuscitation (DCR) focuses on permissive hypotension, hemostatic resuscitation with blood products (with massive transfusion protocol, or MTP), and hemorrhage control with damage control surgery.6,7 MTP seeks to replace what the patient lost: blood.6-9 They don’t need crystalloids, or even just red blood cells (RBCs). They need the whole package including clotting factors (fresh frozen plasma), RBCs, and platelets. DCR and MTP seek to meet this need with defined ratios of blood product administration with a recommended ratio of 1:1:1 for plasma to platelets to RBCs.10-12

MTP does not have a formal, universal definition and it can be used for managing hemorrhage from many different etiologies (not just trauma). Most MTP activations occur for non-trauma indications.13 MTP is typically described as transfusion of > 10 units of blood products within 24 hours, though there are better ways of predicting MTP need.14

The goal of MTP is to resuscitate the patient until definitive surgical control or operative therapy is accomplished, no matter the source of hemorrhage.6-10 MTP seeks to provide a balanced resuscitation with clotting factors (fresh frozen plasma), RBCs and platelets. Literature suggests a 5% increased mortality rate with every minute delay in activation.15

What comprises the products for MTP?


Fresh frozen plasma, packed RBCs, platelets… Seems simple, but what about the specific ratio of products? There is strong retrospective literature supporting a high ratio of platelets and plasma to RBCs, such as a 1:1:1 ratio. This ratio is associated with improved survival and treats intravascular volume deficits, improves coagulopathy associated with trauma and provides oxygen-carrying capacity.

Several studies have evaluated the optimal ratio of plasma, platelets and RBCs. The Prospective, Observational, Multicenter, Major Trauma Transfusion (PROMMTT) Study found patients receiving a ratio of plasma to RBCs and platelets to RBCs of greater than 1:1 experienced decreased six-hour mortality, compared to patients receiving ratios less than 1:2.11

The Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial evaluated mortality at 1 and 30 days, comparing plasma, platelets and RBCs in a 1:1:1 ratio versus 1:1:2 ratio.12 Authors found no improvement in mortality at 1 or 30 days. However, exsanguination within the first 24 hours was decreased in the 1:1:1 group (9.2%) versus the 1:1:2 groups (14.6%), and more patients achieved hemostasis in the 1:1:1 group (86% vs 78%).12 Based on current literature, a 1:1:1 ratio is recommended.

Of note, blood product transfusion is constantly changing, and whole blood and freeze-dried plasma are new therapies on the horizon. However, this article will not discuss these potential game-changers.

When should you activate MTP?

This seems like an easy decision, and that is often the case. Patients with shock due to hemorrhage, notable blood loss or a mangled extremity will need MTP. Other times it isn’t as easy.

The patient may have had one single low blood pressure during transport, or the patient appears well in the resuscitation bay, but keeps experiencing episodes of low BP.  Let’s be honest – using 10 units in 24 hours is not useful in the ED as a marker for activation. Other criteria include four units over four hours or loss of half the blood volume over 24 hours, which again, are not as useful.

One potentially helpful tool is the use of a critical administration threshold (CAT). If you expect to transfuse > 3 units within one hour, strongly consider activating MTP.16,17  Several tools are available to help you decide whether MTP is needed. Those include the ABC score (Assessment of Blood Consumption score), the TASH score (Trauma Associated Severe Hemorrhage), the McLaughlin score and the Shock Index (SI).18-27

The ABC score was designed for use in trauma patients and utilizes four criteria, with a score > 2 predicting need for MTP.18,19 The original retrospective study by Nunez et al. found scores > 2 demonstrate a sensitivity and specificity over 75% and 86%, respectively, for predicting need for MTP, not just RBC transfusion.18

Authors also found the ABC score to be more accurate than the TASH and McLaughlin scores, while also simpler to use.18 The score has been validated, finding the scores > 2 demonstrate sensitivities ranging from 76-90% and specificities ranging from 67-87%.19 The score can be recalculated as the patient’s status changes and is based on objective measures. It does not rely on laboratory values and thus transfusion is not delayed. It requires use of ultrasound, with quality FAST exams, and the most important predictor of need for MTP is the FAST component.


ABC Score (1 point for each)
–          Heart rate > 120 bpm

–          Systolic blood pressure < 90 mm Hg

–          Positive FAST

–          Penetrating injury to the torso


The TASH score uses several variables to identify patients needing MTP.20 A score < 9 is associated with < 5% chance of requiring MTP, while scores > 24 predict the need for MTP with 85% accuracy.20 This score relies on patient characteristics, laboratory values and injuries.

TASH Score
Variable Score
Gender Male = +1

Female = 0

Blood pressure SBP < 100 = +4

SBP < 120 = +1

Hemoglobin < 7 = +8

< 9 = +6

< 10 = +4

< 11 = +3

< 12 = +2

Heart rate > 120 = +2
Base Excess < 10 = +4

< 6 = +3

< 2 = +1

FAST Positive = +3
Unstable pelvic fracture Present = +6
Open or dislocated femur fracture Present = +3


Another score is the McLaughlin Score, which is less complicated than the TASH score with four separate variables: HR > 105, SBP < 110 mm Hg, pH < 7.25, and hematocrit < 32%.21 Though this is easier to use than TASH, it still requires laboratory assessment.

The SI is easy to calculate, as it consists of the heart rate divided by systolic blood pressure.22-25 Normal values range from 0.5-0.7. As the ratio reaches over 0.7, the need for MTP increases: 2X for SI of 0.9, 4X for SI of 1.1, and 7X for SI of 1.3.22-24 When compared to the ABC score, a SI > 1 had a sensitivity of 68% and specificity of 81%, while ABC > 2 had a sensitivity of 47% and specificity of 90%.25 The ABC score was more specific and may decrease false positives, but at the same time increase the risk of a false negative. Authors state that both scores can be utilized to predict need for MTP, though SI does not need the FAST exam.25

How does physician gestalt compare? One study compared the TASH, McLaughlin and ABC scores with gestalt.26 In this study, researchers asked trauma surgeons whether patients were likely to receive blood products 10 minutes after the patient’s arrival, which was compared to the ABC, TASH, and McLaughlin scores.26 Authors found physician gestalt was 65.6% sensitive, with specificity 63.8%.26 Based on results, the TASH score classified more patients requiring need for MTP versus gestalt, but there was no difference between the ABC or McLaughlin scores and gestalt. Another study evaluated the ABC score against clinician judgment in determining need for MTP, finding the ABC predicted need for MTP activation faster than clinical judgment, but also led to greater potential for waste of plasma.27

What should you use? When it comes down to it, you can use the ABC score, the SI, or your clinical gestalt. When the patient displays evidence of shock due to hemorrhage, injury with notable blood loss, mangled extremity, or unstable pelvic fracture, or you anticipate administering > 3 units in the first hour or two, activate MTP.

If the patient does not appear critical due to blood loss, run through the ABC score or SI in conjunction with your FAST exam. If the ABC score is > 2 or SI is approaching 1 or greater, MTP should be strongly considered.  Keep in mind that while the ABC score can overestimate need for MTP, it is consistent in its ability to predict the need for MTP.10 The American College of Surgeons also currently recommends its use.10 Though this over-triaging can use resources, this is likely associated with earlier resuscitation and improved survival.

Based on the patient’s extensive blood loss, you activate the MTP with a phone call and begin transfusing…

That brings us to the end of Part 1. Stay tuned for Part 2!

Part 1 Key Points

  • Hemorrhage requires replacement of what is lost: blood. This does not just consist of RBCs, but also platelets, coagulation factors, and fibrinogen.
  • MTP is a component of damage control resuscitation, which focuses on providing ratio-based, balanced resuscitation (1:1:1 ratio for plasma to platelets to RBCs).
  • Determining when to activate MTP should be based on evidence of bleeding, the expectation of administering > 3 units within the first several hours of resuscitation, or scores such as the ABC score.
  • ABC scores > 2 or elevated SI values are predictive of need for MTP.


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  2. Kauvar DS, Lefering R, Wade CE. Impact of hemorrhage on trauma outcome: an overview of epidemiology, clinical presentations, and therapeutic considerations. J Trauma. 2006;60:S3-S11.
  3. Acosta JA, Yang JC, Winchell RJ, et al. Lethal injuries and time to death in a level I trauma center. Journal of American College of Surgeons. 1998;186:528-533.
  4. Brohi K, Singh J, Heron M, Coats T. Acute traumatic coagulopathy. J Trauma. 2003;54:1127-1130.
  5. MacLeod JB, Lynn M, McKenney MG, Cohn SM, Murtha M. Early coagulopathy predicts mortality in trauma. J Trauma. 2003;55:39-44.
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  7. Holcomb JB. Damage control resuscitation. J Trauma. 2007; 62:S36-S37.
  8. Cotton BA, Gunter OLD, Ishell J, et al. Damage control hematology: the impact of a trauma exsanguination protocol on survival and blood product utilization. J Trauma. 2008; 64: 1177-1182; discussion 1182-1183.
  9. Tieu BH, Holcomb JD, Schreiber MA. Coagulopathy: its pathophysiology and treatment in the injured patient. World Journal of Surgery. 2007; 31: 1055-1064.
  10. ACS Trauma Quality Improvement Program. Massive Transfusion in Trauma Guidelines.  Accessed on 03 February 2019.
  11. Holcomb JB,del Junco DJFox EE, et al. The prospective, observational, multicenter, major trauma transfusion (PROMMTT) study: comparative effectiveness of a time-varying treatment with competing risks. JAMA Surg. 2013 Feb;148(2):127-36.
  12. Holcomb JB, Tilley BC, Baraniuk S, et al. Transfusion of Plasma, Platelets, and Red Blood Cells in a 1:1:1 vs a 1:1:2 Ratio and Mortality in Patients With Severe Trauma: The PROPPR Randomized Clinical Trial. 2015;313(5):471–482.
  13. Thomasson RR,Yazer MHGorham JD, et al. International assessment of massive transfusion protocol contents and indications for activation.  2019 Feb 5. doi: 10.1111/trf.15149. [Epub ahead of print]
  14. Hardy JF,De Moerloose PSamama MGroupe d’intérêt en Hémostase Périopératoire. Massive transfusion and coagulopathy: pathophysiology and implications for clinical management. Can J Anaesth. 2004 Apr;51(4):293-310.
  15. Meyer DE,Vincent LEFox EE, et al. Every minute counts: Time to delivery of initial massive transfusion cooler and its impact on mortality. J Trauma Acute Care Surg. 2017 Jul;83(1):19-24.
  16. Pottecher J, Ageron FX, Fauché C, et al. Prehospital shock index and pulse pressure/heart rate ratio to predict massive transfusion after severe trauma: Retrospective analysis of a large regional trauma database. J Trauma Acute Care Surg. 2016;81(4):713–722.
  17. Chang R, Holcomb JB. Optimal fluid therapy for traumatic hemorrhagic shock. Crit Care Clin. 2017;33(1):15–36.
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  19. Cotton BA, Dossett LA, Haut ER, et al. Multicenter Validation of a Simplified Score to Predict Massive Transfusion in Trauma. Journal of Trauma:  Injury, Infection, and Critical Care. 2010;69:S33-S39.
  20. Yücel N,Lefering RMaegele M, et al. Trauma Associated Severe Hemorrhage (TASH)-Score: probability of mass transfusion as surrogate for life threatening hemorrhage after multiple trauma. J Trauma. 2006 Jun;60(6):1228-36; discussion 1236-7.
  21. McLaughlin DF, Niles SE, Salinas J, et al. A predictive model for massive transfusion in combat casualty patients. J Trauma. 2008; 64:S57–S63; discussion S63.
  22. Allgower M, Burri C. The “shock-index”. Dtsch med Wochen schr 1967;92(43):1947-1950.
  23. Vandromme MJ,Griffin RLKerby JD, et al. Identifying risk for massive transfusion in the relatively normotensive patient: utility of the prehospital shock index. J Trauma. 2011 Feb;70(2):384-8; discussion 388-90.
  24. Mutschler M, Nienaber U, Munzberg M, et al. The Shock Index revisited – a fast guide to transfusion requirement? A retrospective analysis on 21,853 patients derived from the TraumaRegister DGU®. Critical Care 2013;17:R172.
  25. Schroll R, Swift D, Tatum D, et al.  Accuracy of shock index versus ABC score to predict need for massive transfusion in trauma patients.  Injury. 2018; 49 (1): 15-19.
  26. Pommerening MJ, Goodman MD, Holcomb JB, et al. Clinical gestalt and the prediction of massive transfusion after trauma. Injury. 2015; 46: 807-813.
  27. Motameni ATHodge RAMcKinley WI, et al. The use of ABC score in activation of massive transfusion: The yin and the yang. J Trauma Acute Care Surg.2018 Aug;85(2):298-302.


Brit Long, MD is an EM Attending Physician at San Antonio Uniformed Services Health Education Consortium.

Alex Koyfman, MD is a Clinical Assistant Professor of Emergency Medicine at UT Southwestern Medical Center and an Attending Physician at Parkland Memorial Hospital. He is also Editor-in-Chief for emDocs.

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