Early aggressive use of fresh frozen plasma does not improve outcome in critically injured trauma patients

Emerging therapies in traumatic hemorrhage control

PURPOSE OF REVIEW

Care of the injured patient is a dynamic process. Hemorrhage remains the primary cause of preventable death after trauma. Rapid and effective early care can improve survival and outcomes. Emerging therapies to address traumatic hemorrhage will be discussed.

RECENT FINDINGS

Current concepts in trauma care include damage control resuscitation with rapid surgical correction of bleeding; prevention of the development of the lethal triad; limitation of crystalloid administration and application of high ratios of plasma and platelets to packed red blood cells. Prehospital resuscitation strategies can effect care of the hemorrhaging trauma patient, as well. The goal should be to preserve vital functions without increasing the risk for further bleeding. The concept of hypotensive resuscitation has been formulated to address this issue. The type of resuscitation fluid also plays an important role, with novel fluids currently being studied for routine use. Compressible hemorrhage constitutes an important component of potentially survivable injury. Hemostatic dressings and tourniquets can prove essential to the management of combat and civilian wounds.

SUMMARY

Given the potential to preserve life with appropriate attention applied to the bleeding trauma victim, it is vitally important to explore the options currently available and continue to make improvements in care.

Clinical review: Fresh frozen plasma in massive bleedings - more questions than answers

Fresh frozen plasma (FFP) is indicated for the management of massive bleedings. Recent audits suggest physician knowledge of FFP is inadequate and half of the FFP transfused in critical care is inappropriate. Trauma is among the largest consumers of FFP. Current trauma resuscitation guidelines recommend FFP to correct coagulopathy only after diagnosed by laboratory tests, often when overt dilutional coagulopathy already exists. The evidence supporting these guidelines is limited and bleeding remains a major cause of trauma-related death. Recent studies demonstrated that coagulopathy occurs early in trauma. A novel early formula-driven haemostatic resuscitation proposes addressing coagulopathy early in massive bleedings with FFP at a near 1:1 ratio with red blood cells. Recent retrospective reports suggest such strategy significantly reduces mortality, and its use is gradually expanding to nontraumatic bleedings in critical care. The supporting studies, however, have bias limiting the interpretation of the results. Furthermore, logistical considerations including need for immediately available universal donor AB plasma, short life after thawing, potential waste and transfusion-associated complications have challenged its implementation. The present review focuses on FFP transfusion in massive bleeding and critically appraises the evidence on formula-driven resuscitation, providing resources to allow clinicians to develop informed opinion, given the current deficient and conflicting evidence.

Optimal use of blood products in severely injured trauma patients

Injury is the leading cause of life years lost in the United States, and uncontrolled hemorrhage is the leading cause of potentially preventable death. Traditionally, these patients have been serially resuscitated with large volumes of crystalloid and/or colloids and red blood cells, followed by smaller amounts of plasma and platelets. Transfusion data coming first from the ongoing war in Iraq and Afghanistan and followed by multiple civilian studies have brought into question this tradition-based practice. Numerous recent retrospective single and multicenter studies have associated improved outcomes with earlier and increased use of plasma and platelets. These data have stimulated significant interest in studying massively transfused trauma patients. Most clinicians have concluded that the optimal timing and quantity of blood products in the treatment of hypothermic, coagulopathic, and acidotic trauma patients are unclear. Although there are strongly held opinions and long-standing traditions in their use, there are little quality data within which to logically guide resuscitation therapy. A multicenter prospective observational study is ongoing, and randomized trials are planned. This review will address the issues raised previously and describe recent trauma patient outcome data utilizing predetermined plasma:platelet:red blood cell transfusion ratios, and possibilities for future transfusion products and research.

Optimal use of blood in trauma patients

Injury is rapidly becoming the leading cause of death worldwide, and uncontrolled hemorrhage is the leading cause of potentially preventable death. In addition to crystalloid and/or colloid based resuscitation, severely injured trauma patients are routinely transfused RBCs, plasma, platelets, and in some centers either cryoprecipitate or fibrinogen concentrates or whole blood. Optimal timing and quantity of these products in the treatment of hypothermic, coagulopathic and acidotic trauma patients is unclear. The immediate availability of these components is important, as most hemorrhagic deaths occur within the first 3-6h of patient arrival. While there are strongly held opinions and longstanding traditions in their use, there are little data within which to logically guide resuscitation therapy. Many current recommendations are based on euvolemic elective surgery patients and incorporate laboratory data parameters not widely available in the first few minutes after patient arrival. Finally, blood components themselves have evolved over the last 30 years, with great attention paid to product safety and inventory management, yet there are surprisingly limited clinical outcome data describing the long term effects of these changes, or how the components have improved clinical outcomes compared to whole blood therapy. When focused on survival of the rapidly bleeding trauma patient, it is unclear if current component therapy is equivalent to whole blood transfusion. In fact data from the current war in Iraq and Afghanistan suggest otherwise. All of these factors have contributed to the current situation, whereby blood component therapy is highly variable and not driven by long term patient outcomes. This review will address the issues raised above and describe recent trauma patient outcome data utilizing predetermined plasma:platelet:RBC transfusion ratios and an ongoing prospective observational trauma transfusion study.

Massive transfusion: new insights

Massive transfusion (MT) is used for the treatment of uncontrolled hemorrhage. Earlier definitive control of life-threatening hemorrhage has significantly improved patient outcomes, but MT is still required. A number of recent advances in the area of MT have emerged, including the use of "hypotensive" or "delayed" resuscitation for victims of penetrating trauma before hemorrhage is controlled and "hemostatic resuscitation" with increased use of plasma and platelet transfusions in an attempt to maintain coagulation. These advances include the earlier use of hemostatic blood products (plasma, platelets, and cryoprecipitate), recombinant factor VIIa as an adjunct to the treatment of dilutional and consumptive coagulopathy, and a reduction in the use of isotonic crystalloid resuscitation. MT protocols have been developed to simplify and standardize transfusion practices. The authors of recent studies have advocated a 1:1:1 ratio of packed RBCs to fresh frozen plasma to platelet transfusions in patients requiring MT to avoid dilutional and consumptive coagulopathy and thrombocytopenia, and this has been associated with decreased mortality in recent reports from combat and civilian trauma. Earlier assessment of the exact nature of abnormalities in hemostasis has also been advocated to direct specific component and pharmacologic therapy to restore hemostasis, particularly in the determination of ongoing fibrinolysis.

Assessing response to changing plasma/red cell ratios in a bleeding trauma patient

Recent military experience suggests that transfusing fresh frozen plasma and packed red cells in a 1:1 ratio may improve survival in exsanguinating trauma patients. We report the case of a single patient who required massive transfusion after suffering a single gunshot wound. Initially, the patient received FFP:PRBC in 1:2 ratio, but this did not correct laboratory parameters except for INR and clotting factor VII level, which were likely normalized by treatment with recombinant activated factor VII. After receiving FFP:PRBC in a 4:5 ratio, he continued to bleed and his coagulation profile showed no appreciable improvement. In the final phase, he received FFP:PRBC in a 7:5 ratio and his laboratory parameters of coagulopathy normalized, except for factor V level which was improved. He also clinically stopped bleeding.

Current trends in resuscitation strategy for the multiply injured patient

The ideal resuscitation strategy for multiply injured patients remains a topic of ongoing debate. At present, no consensus has been reached on the ideal fluid for early resuscitation and on the threshold for blood product transfusions. The concept of "permissive hypotension" for bleeding trauma patients furthermore contributes to the controversy in the field, particularly as it relates to blunt trauma and to patients with associated head injuries. Finally, postinjury coagulopathy is a poorly defined entity, and current resuscitation strategies lack strong evidence-based scientific support. This review article provides a brief overview of the existing resuscitation protocols for multiply injured patients, including ATLS and "damage control", and will address developing controversies in the field.

Resuscitation and transfusion principles for traumatic hemorrhagic shock

The transfusion approach to massive hemorrhage has continually evolved since it began in the early 1900s. It started with fresh whole blood and currently consists of virtually exclusive use of component and crystalloid therapy. Recent US military experience has reinvigorated the debate on what the most optimal transfusion strategy is for patients with traumatic hemorrhagic shock. In this review we discuss recently described mechanisms that contribute to traumatic coagulopathy, which include increased anti-coagulation factors and hyperfibrinolysis. We also describe the concept of damage control resuscitation (DCR), an early and aggressive prevention and treatment of hemorrhagic shock for patients with severe life-threatening traumatic injuries. The central tenants of DCR include hypotensive resuscitation, rapid surgical control, prevention and treatment of acidosis, hypothermia, and hypocalcemia, avoidance of hemodilution, and hemostatic resuscitation with transfusion of red blood cells, plasma, and platelets in a 1:1:1 unit ratio and the appropriate use of coagulation factors such as rFVIIa and fibrinogen-containing products (fibrinogen concentrates, cryoprecipitate). Fresh whole blood is also part of DCR in locations where it is available. Additional concepts to DCR since its original description that can be considered are the preferential use of "fresh" RBCs, and when available thromboelastography to direct blood product and hemostatic adjunct (anti-fibrinolytics and coagulation factor) administration. Lastly we discuss the importance of an established massive transfusion protocol to rapidly employ DCR and hemostatic resuscitation principles. While the majority of recent trauma transfusion papers are supportive of these general concepts, there is no Level 1 or 2 data available. Taken together, the preponderance of data suggests that these concepts may significantly decrease mortality in massively transfused trauma patients.

Surgical response to multiple casualty incidents following single explosive events

BACKGROUND

Modern publications on response to single explosive events are from non-US hospitals, predate current resuscitation guidelines and lack detail on surgical and intensive care unit (ICU) requirements. The objective of this study is to provide a contemporary account of surge response to multiple casualty incidences following explosive events managed at a US trauma hospital in Iraq.

METHODS

Observational study and retrospective chart review of 72-hour transfusion, operating room, and ICU resource utilization from 3 multiple casualty incidences managed at the US Air Force Theater Hospital, Balad AB, Iraq between February and April 2008.

RESULTS

Fifty patients were treated with a mean injury severity score of 19. Forty-eight percent (n = 24) of casualties required blood transfusion with 4 patients receiving 43% (N = 74 units) of the packed red blood cells (pRBC). An average of 3.5 and 3.8 units of pRBC and plasma, respectively, was transfused per casualty (pRBC:plasma ratio of 1:1.1). Seventy-six percent (n = 38) of patients required immediate operation upon initial presentation. A total of 191 procedures were performed in parallel during 75 operations (3.8 procedures per casualty). Fifty percent (n = 25) of patients required ICU admission with nearly the same number (n = 24) requiring mechanical ventilator support beyond that required for operation. All cause, in-hospital mortality was 8% (n = 4).

CONCLUSIONS

Results from this study provide a contemporary assessment of transfusion, surgical, and intensive care resource requirements after a single explosive event. Data from this experience may translate into useful guidelines for emergency planners worldwide.

Impact of transfusion of fresh-frozen plasma and packed red blood cells in a 1:1 ratio on survival of emergency department patients with severe trauma

OBJECTIVES

Coagulopathy is common after severe trauma and occurs very early after the initial insult. Some investigators have suggested early and aggressive treatment of the trauma-induced coagulopathy by transfusion of fresh-frozen plasma (FFP) and packed red blood cells (PRBC) in a 1:1 ratio. This evidence-based emergency medicine (EBM) review evaluates the evidence regarding the impact of 1:1 ratio of FFP:PRBC transfusion on survival of emergency department (ED) patients with severe trauma.

METHODS

The MEDLINE, EMBASE, Cochrane Library, and other databases were searched. Studies were selected for inclusion if they included trauma patients who required blood transfusion. The outcome measures of interest included mortality and adverse effects of high FFP:PRBC ratios. For comparison, the patients were classified into high ratio (1:1, defined as a ratio of 1:< or =1.5) and low ratio (1:>1.5) groups.

RESULTS

The authors did not identify any randomized controlled trials (RCT), but included four observational studies (three retrospective registry and one prospective cohort studies), which enrolled 1,511 patients cumulatively. One study found a statistically significant difference in mortality rate, favoring high FFP:PRBC ratio (relative risk = 0.72, 95% confidence interval [CI] = 0.59 to 0.89), while three studies showed no benefits. One study reported higher rates of sepsis and single/multiorgan failure (MOF), and another study revealed a higher risk of nosocomial infections and acute respiratory distress syndrome (ARDS) in the high FFP:PRBC ratio group.

CONCLUSION

Three retrospective registry reviews with suboptimal methodologies and one prospective cohort study provide inadequate evidence to support or refute the use of a high FFP:PRBC ratio in patients with severe trauma.

Fibrinogen metabolic responses to trauma

Coagulation complications are significant contributors to morbidity and mortality in trauma patients. Although the lethal triad of hypothermia, acidosis and coagulopathy has been recognized for over a decade, the underlying mechanisms related to the development of coagulopathy remain unclear. Recent data suggest that decreased fibrinogen levels contribute to the development of coagulation disorders. Thus, regulation of fibrinogen availability, not fully understood at present, may play an important role in survival of trauma patients. This review summarizes the recent findings of the studies that have explored mechanisms related to changes in fibrinogen availability following trauma-related events. Trauma alters fibrinogen metabolism in a variety of ways: hemorrhage – accelerated fibrinogen breakdown; hypothermia – inhibited fibrinogen synthesis; and, acidosis – accelerated fibrinogen breakdown. However, hemorrhage, hypothermia andcidosis all result in a consistent outcome of fibrinogen availability deficit, supporting the notion of fibrinogen supplementation in trauma patients with coagulation defects. Future prospective clinical trials are needed to confirm the beneficial effects of fibrinogen supplementation in trauma patients with bleeding complications.