By Betty Tran, MD, MSc, Editor

SYNOPSIS: This was a narrative review of societal recommendations for initiation of massive transfusion protocols based on objective scoring systems and clinical assessment and criteria for termination of protocols.

SOURCE: Foster JC, et al. Initiation and termination of massive transfusion protocols: Current strategies and future prospects. Anesth Analg 2017;125:2045-2055.

Massive transfusion protocols (MTPs) have been associated with significant improvements in patient survival, reductions in blood product use and waste, and decreased complications when compared to massive transfusion (MT) events in hospitals without protocols.1-3 In this narrative review, Foster et al summarized the most up-to-date recommendations regarding MTP initiation and termination. The sources for these guidelines were from the American College of Surgeons, the European Society for Advanced Bleeding Care in Trauma (ABC-Trauma), and the American Society of Anesthesiologists; an additional literature review of papers published between December 2006 and January 2017 involving the keyword “massive transfusion” also was performed. Notably, much of the literature on MTPs involves the trauma population. The authors hypothesized that one explanation for the lack of observed benefits of MTPs in the nontrauma population may be the higher rate of MTP “overactivations” in this group (i.e., MTP activations in which patients do not need to receive the amount of blood products required to meet the definition of an MT). Therefore, precise guidelines for guiding MTP initiation and termination in nontrauma patients are lacking.

Each of the aforementioned societies recommends a systematic approach to MTP initiation, which combines a validated MT prediction score with a clinical assessment of tissue perfusion and estimated blood loss, which usually considers factors such as the need for blood transfusions in the ED/trauma bay, need for immediate surgery or angioembolization to control bleeding, persistent hemodynamic instability after fluid resuscitation, and mechanism and severity of injury. The simplest MT prediction score is the Assessment of Blood Consumption (ABC) score, which includes four variables, each worth 1 point with a positive threshold of > 2: systolic blood pressure < 90, heart rate > 120, focused ultrasound assessment for trauma positive, and penetrating mechanism of injury. The ABC score is reported as 75-90% sensitive and 67-88% specific regarding predicting MT requirements within 24 hours of trauma, with a positive predictive value of 55% and a negative predictive value of 97%.

Instead of the ABC score, the ABC-Trauma guidelines recommend the Trauma Associated Severe Hemorrhage (TASH) score, which is more complicated (seven variables, 28 total points, weighted, positive score > 16) and involves two lab values that require time to result (hemoglobin and base excess).

Validation and revalidation studies have shown that the TASH is similar to the ABC score in that a negative score accurately predicts patients who will not require a MT, but a positive score often will incorrectly identify MT needs in someone who ultimately does not need it. For nontrauma patients, the authors suggested considering “intensity of resuscitation” efforts as a surrogate marker for hemorrhage severity, with a threshold of 3-4 units of packed red blood cells per hour as a possible identifier of patients who could benefit from formal MTP initiation.

In terms of MTP termination, collective societal guidelines recommend stopping based on clinical judgment and the fulfillment of three broad criteria: bleeding source control or decelerating rate of blood loss, stable or improving hemodynamics, and decreasing or absent vasopressor requirements. ABC-Trauma also provides specific lab resuscitation targets in terms of hemoglobin (between 7-9 g/dL), prothrombin time and partial thromboplastin time (< 1.5 × normal values), platelets (> 50 × 109/L or > 100 × 109/L in traumatic brain injury or active bleeding), and fibrinogen (> 1.5-2 g/L). This is based on some evidence that conventional coagulation assay-guided resuscitation added to conventional algorithms is associated with fewer blood transfusions, reduced morbidity, and an improvement in hemostatic markers.4-5 However, no randomized, controlled trials directly comparing algorithm-guided vs. laboratory-guided resuscitation methods exist.

COMMENTARY

This review provides a detailed summary and analysis of the current literature and guidelines on MTP initiation and termination in the hemorrhaging trauma population. At the heart of this topic is the balance between timely and adequate resuscitation for patients, which saves lives, and the need to avoid blood product waste and morbidities associated with massive transfusion.6 It is worth mentioning that although the guidelines are targeted to the trauma population, there is significant variation internationally and even in the United States regarding type/mechanism of traumatic injury, which will have an effect on how the MT prediction scores perform and on the use of MTPs in individual hospitals. For example, the authors noted that in an urban European setting, about 80% of penetrating injuries are stab wounds (overall incidence, 4.7%), and 20% are gunshot wounds (overall incidence, 1.1%); in contrast, in one U.S. urban trauma center, 5.8% of all trauma are gunshot wounds. In addition, although not every hospital is a trauma center, MT situations also arise in nontrauma patients. In addition, there is a need for clear guidelines regarding MTP initiation and termination, which are lacking. At this time, principles guiding the initiation and termination of MTPs, especially in nontrauma situations, will need to be determined by each medical center based on its individual experiences and specific patient populations. Hopefully, the recommendations provided in this review can serve as a starting point for discussion.

REFERENCES

  1. Cotton BA, et al. Predefined massive transfusion protocols are associated with a reduction in organ failure and postinjury complications. J Trauma 2009;66:41-48.
  2. Dente CJ, et al. Improvements in early mortality and coagulopathy are sustained better in patients with blunt trauma after institution of a massive transfusion protocol in a civilian level 1 trauma center. J Trauma 2009;66:1616-1624.
  3. Riskin DJ, et al. Massive transfusion protocols: The role of aggressive resuscitation versus product ratio in mortality reduction. J Am Coll Surg 2009;209:198-205.
  4. Nardi G, et al. Trauma-induced coagulopathy: Impact of an early coagulation support protocol on blood product consumption, mortality and costs. Crit Care 2015;19:83.
  5. Nascimento B, et al. Effect of a fixed-ratio (1:1:1) transfusion protocol versus laboratory-results-guided transfusion in patients with severe trauma: A randomized feasibility trial. CMAJ 2013;185:583-589.
  6. Sihler KC, Napolitano LM. Complications of massive transfusion. Chest 2010;137:209-220.