A Proactive Approach to the Coagulopathy of Trauma: The Rationale and Guidelines for Treatment

NATO Blood Panel perspectives on changes to military prehospital resuscitation policies: current and future practice

The North Atlantic Treaty Organization (NATO) Blood Panel exists to promote interoperability of transfusion practice between NATO partners. However, it has served as an important forum for the development of prehospital transfusion and transfusion in the austere environment. There are synergies with the trauma hemostasis and oxygen research community especially in the areas of innovation and research. Four presentations are summarized together with a review of some scientific principles. The past decade has already seen significant changes in early transfusion support. Sometimes practice has preceded the evidence and has stretched regulatory and logistic constraints. Ethical and philosophical issues are also important and require us to question "should we" and not just "could we." The challenge for the combined communities is to continue to optimize transfusion support underpinned by evidence-based excellence.

A national common massive transfusion protocol (MTP) is a feasible and advantageous option for centralized blood services and hospitals

BACKGROUND

A common national MTP was jointly implemented in 2011 by the national blood service (Blood Services Group) and seven participating acute hospitals to provide rapid access to transfusion support for massively haemorrhaging patients treated in all acute care hospitals.

METHODS

Through a systematic clinical workflow, blood components are transfused in a ratio of 1:1:1 (pRBC: whole blood-derived platelets: FFP), together with cryoprecipitate for fibrinogen replacement. The composition of components for the MTP is fixed, although operational aspects of the MTP can be adapted by individual hospitals to suit local hospital workflow. The MTP could be activated in support of any patient with critical bleeding and at risk of massive transfusion, including trauma and non-trauma general medical, surgical and obstetric patients.

RESULTS

There were 434 activations of the MTP from October 2011 to October 2013. Thirty-nine per cent were for trauma patients, and 30% were for surgical patients with heavy intra-operative bleeding, with 25% and 6% for patients with gastrointestinal bleeding and peri-partum haemorrhage, respectively. Several hospitals reported reduction in mean time between request and arrival of blood. Mean transfusion ratio achieved was one red cell unit: 0·8 FFP units: 0·8 whole blood-derived platelet units: 0·4 units of cryoprecipitate. Although cryoprecipitate usage more than doubled after introduction of MTP, there was no significant rise in overall red cells, platelet and FFP usage following implementation.

CONCLUSION

This successful collaboration shows that shared transfusion protocols are feasible and potentially advantageous for hospitals sharing a central blood provider.

Trauma care today, what's new?

Injury is the fourth leading cause of death in the US, and the leading cause of death in younger age. Trauma is primarily a disease of the young and accounts for more years of productive life lost than any other illness. Consequently, almost every health care provider encounters trauma patients from time to time. Many of these patients are critically ill and pose several challenges in the acute phase, including airway and ventilation, fluid management, intracranial pressure control, etc. In the last decade, several strategies and treatment options have been studied in trauma care along with improvement in technologies. In this review, we will discuss a few of the new developments and updates in trauma care.

Intra-operative correction of acidosis, coagulopathy and hypothermia in combat casualties with severe haemorrhagic shock

We assessed acidosis, coagulopathy and hypothermia, before and after surgery in 51 combat troops operated on for severe blast injury. Patients were transfused a median (IQR [range]) of 27 (17-38 [5-84]) units of red cell concentrate, 27 (16-38 [4-83]) units of plasma, 2.0 (0.5-3.5 [0-13.0]) units of cryoprecipitate and 4 (2-6 [0-17]) pools of platelets. The pH, base excess, prothrombin time and temperature increased: from 7.19 (7.10-7.29 [6.50-7.49]) to 7.45 (7.40-7.51 [7.15-7.62]); from -9.0 (-13.5 to -4.5 [-28 to -2]) mmol.l⁻¹ to 4.5 (1.0-8.0 [-7 to +11]) mmol.l⁻¹; from 18 (15-21 [9-24]) s to 14 (11-18 [9-21]) s; and from 36.1 (35.1-37.1 [33.0-38.1]) °C to 37.4 (37.0-37.9 [36.0-38.0]) °C, respectively. Contemporary intra-operative resuscitation strategies can normalise the physiological derangements caused by haemorrhagic shock.

[Control of bleeding in the military environment]

One of the basics of military medicine is the control of haemorrhagic shock. Haemorrhage is the first cause of preventable death in combat, with the adequate control of bleeding being considered as fundamental to estimate the survival of the combatant as well as therapeutic support aimed at minimising blood loss being a challenge within military health logistics. The aim of this work is to review the medical and logistics advances in the treatment of bleeding in the military environment and combat during the latest conflicts, and to describe what is the current contribution of the Spanish Armed Forces and to profile future lines of investigation.

Fibrinogen γ-chain peptide-coated, ADP-encapsulated liposomes rescue thrombocytopenic rabbits from non-compressible liver hemorrhage

BACKGROUND

We developed a fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV [H12])-coated, ADP-encapsulated liposome (H12-[ADP]-liposome) that accumulates at bleeding sites via interaction with activated platelets via glycoprotein IIb-IIIa and augments platelet aggregation by releasing ADP.

OBJECTIVE

To evaluate the efficacy of H12-(ADP)-liposomes for treating liver hemorrhage in rabbits with acute thrombocytopenia.

METHODS

Thrombocytopenia (platelets < 50 000 μL(-1)) was induced in rabbits by repeated blood withdrawal (100 mL kg(-1) in total) and isovolemic transfusion of autologous washed red blood cells. H12-(ADP)-liposomes with platelet-poor plasma (PPP), platelet-rich plasma (PRP), PPP, ADP liposomes with PPP or H12-(PBS)-liposomes/PPP, were administered to the thrombocytopenic rabbits, and liver hemorrhage was induced by penetrating liver injury.

RESULTS

Administration of H12-(ADP)-liposomes and of PRP rescued all thrombocytopenic rabbits from liver hemorrhage as a result of potent hemostasis at the liver bleeding site, although rabbits receiving PPP or ADP liposomes showed 20% survival in the first 24 h. Administration of H12-(ADP)-liposomes and of PRP suppressed both bleeding volume and time from the site of liver injury. H12-(phosphate-buffered saline)-liposomes lacking ADP also improved rabbit survival after liver hemorrhage, although their hemostatic effect was weaker. In rabbits with severe thrombocytopenia (25 000 platelets μL(-1)), the hemostatic effects of H12-(ADP)-liposomes tended to be attenuated as compared with those of PRP treatment. Histologic examination revealed that H12-(ADP)-liposomes accumulated at the bleeding site in the liver. Notably, neither macrothombi nor microthrombi were detected in the lung, kidney or liver in rabbits treated with H12-(ADP)-liposomes.

CONCLUSIONS

H12-(ADP)-liposomes appear to be a safe and effective therapeutic tool for acute thrombocytopenic trauma patients with massive bleeding.

Modern military surgery

The types of explosive devices used in warfare and the pattern of war wounds have changed in recent years. There has, for instance, been a considerable increase in high amputation of the lower limb and unsalvageable leg injuries combined with pelvic trauma.

The conflicts in Iraq and Afghanistan prompted the Department of Military Surgery and Trauma in the United Kingdom to establish working groups to promote the development of best practice and act as a focus for research.

In this review, we present lessons learnt in the initial care of military personnel sustaining major orthopaedic trauma in the Middle East.

Hypoperfusion in severely injured trauma patients is associated with reduced coagulation factor activity

BACKGROUND

Recent studies have shown that acute traumatic coagulopathy is associated with hypoperfusion, increased plasma levels of soluble thrombomodulin, and decreased levels of protein C but with no change in factor VII activity. These findings led to the hypothesis that acute traumatic coagulopathy is primarily due to systemic anticoagulation, by activated protein C, rather than decreases in serine protease activity. This study was designed to examine the effect of hypoperfusion secondary to traumatic injury on the activity of coagulation factors.

METHODS

Post hoc analysis of prospectively collected data on severely injured adult trauma patients presenting to a single trauma center within 120 minutes of injury. Venous blood was analyzed for activity of factors II, V, VII, VIII, IX, X, and XI. Base deficit from arterial blood samples was used as a marker of hypoperfusion.

RESULTS

Seventy-one patients were identified. The activity of factors II, V, VII, IX, X, and XI correlated negatively with base deficit, and after stratification into three groups, based on the severity of hypoperfusion, a statistically significant dose-related reduction in the activity of factors II, VII, IX, X, and XI was observed. Hypoperfusion is also associated with marked reductions in factor V activity levels, but these appear to be relatively independent of the degree of hypoperfusion. The activity of factor VIII did not correlate with base deficit.

CONCLUSIONS

Hypoperfusion in trauma patients is associated with a moderate, dose-dependent reduction in the activity of coagulation factors II, VII, IX, X, and XI, and a more marked reduction in factor V activity, which is relatively independent of the severity of shock. These findings suggest that the mechanisms underlying decreased factor V activity--which could be due to activated protein C mediated cleavage, thus providing a possible link between the proposed thrombomodulin/thrombin-APC pathway and the serine proteases of the coagulation cascade--and the reductions in factors II, VII, IX, X, and XI may differ. Preservation of coagulation factor activity in the majority of normally and moderately hypoperfused patients suggests that aggressive administration of plasma is probably only indicated in severely hypoperfused patients. Markers of hypoperfusion, such as base deficit, might be better and more readily available predictors of who require coagulation support than international normalized ratio or activated partial thromboplastin time.

Massive transfusion

Massive Transfusion is a part of Damage Control Resuscitation. The aim of transfusion therapy is to restore oxygen delivery to poorly perfused tissues and to treat the acute coagulopathy of trauma. The severity and complexity of modern injuries have led to the use of swift, protocol-driven care with the use of'Shock Packs' and management of metabolic complications. The proactive treatment of the coagulopathy has been termed Haemostatic Resuscitation. The delivery of this transfusion capability has required an increasingly sophisticated logistic and laboratory response. New operational capabilities have included cold chain solutions; laboratory management information systems; platelet apheresis and ROTEM. This investment in the massive transfusion capability has delivered rapid resuscitation. It has also enabled clinicians to direct individualised transfusion support following initial resuscitation i.e. goal directed therapy. Future technical solutions should further support the prehospital delivery of transfusion while addressing the logistic tail. However, the key to success is the knowledge and skills of frontline staff to deliver safe and appropriate blood transfusion.

Transfusion practice in major obstetric haemorrhage: lessons from trauma

The management of massive haemorrhage with blood products is changing as evidence arrives from civilian and military trauma. Rapid early replacement of coagulation factors and platelets is now becoming central to improving outcome, usually given in higher ratios with respect to red cell units than previously recommended and using empiric transfusion based on clinical rather than laboratory parameters. The management of three cases of major obstetric haemorrhage based on these principles is presented. Packed red blood cells, fresh frozen plasma, platelets and cryoprecipitate were transfused in the ratios 5:2:2:1, 4.5:1:1:1 and 4.5:2:1:1. Each patient had acceptable full blood count and coagulation results after surgery and all made an uneventful recovery. These outcomes support the opinion that major obstetric haemorrhage can be managed in a similar fashion to blood loss in trauma. Recommendations from the Association of Anaesthetists of Great Britain and Ireland, and the UK National Patient Safety Agency should be considered during major obstetric haemorrhage.

Damage Control Philosophy in Polytrauma

Severe traumatic injury is a public health care problem; with injuries accounting for 12% of the global mortality. Continued improvement in the survival of severely injured trauma patients is a paramount goal. Bailout/damage control surgery following trauma has developed as a major advance in surgical practice in the last twenty years. The principles of damage control surgery defied the traditional surgical teaching of definitive operative intervention and were slow to be adopted. Currently, damage control surgery has been successfully utilized to manage traumatic thoracic, abdominal, extremity, and peripheral vascular injuries. In addition, damage control surgery has been extrapolated for use in general, vascular, cardiac, urologic, and orthopaedic surgery. Stone et al were the first to describe the "bailout" approach of staged surgical procedures for severely injured patients. This approach emerged after their observation that early death following trauma was associated with severe metabolic and physiologic derangements following severe exsanguinating injuries. Profound shock along with major blood loss initiates the cycle of hypothermia, acidosis, and coagulopathy. During the 1980s, hypothermia, acidosis, and coagulopathy were described as the "trauma triangle of death" which makes the prolonged and definitive operative management of trauma patients dangerous. The management technique, now described as "damage control" by Rotondo et al, involves a multiphase approach, in which reoperation occurs after correction of physiologic abnormalities.

The role of trauma scoring in developing trauma clinical governance in the Defence Medical Services

This paper discusses mathematical models of expressing severity of injury and probability of survival following trauma and their use in establishing clinical governance of a trauma system. There are five sections: (i) Historical overview of scoring systems--anatomical, physiological and combined systems and the advantages and disadvantages of each. (ii) Definitions used in official statistics--definitions of 'killed in action' and other categories and the importance of casualty reporting rates and comparison across conflicts and nationalities. (iii) Current scoring systems and clinical governance--clinical governance of the trauma system in the Defence Medical Services (DMS) by using trauma scoring models to analyse injury and clinical patterns. (iv) Unexpected outcomes--unexpected outcomes focus clinical governance tools. Unexpected survivors signify good practice to be promulgated. Unexpected deaths pick up areas of weakness to be addressed. Seventy-five clinically validated unexpected survivors were identified over 2 years during contemporary combat operations. (v) Future developments--can the trauma scoring methods be improved? Trauma scoring systems use linear approaches and have significant weaknesses. Trauma and its treatment is a complex system. Nonlinear methods need to be investigated to determine whether these will produce a better approach to the analysis of the survival from major trauma.

Use of thromboelastometry in the assessment of coagulation before epidural insertion after massive transfusion

A British soldier presented to the UK Field Hospital, Afghanistan with bilateral traumatic lower limb amputations. Resuscitation and surgery followed accepted damage control principles. Blood component therapy was in keeping with UK military guidelines and included platelets and cryoprecipitate. The patient's trachea was extubated following insertion of an effective epidural. Ten days later, in the UK, he developed neurological symptoms and the presence of a subdural haematoma was confirmed on magnetic resonance imaging. Conventional laboratory coagulation results in this patient were above accepted limits for epidural insertion; however, thromboelastometry before insertion was suggestive of reduced platelet function. This case highlights the risk of relying solely on platelet count as a marker of platelet function following massive transfusion. Thromboelastometry provides additional information for the assessment of coagulation and should form part of the assessment of coagulation following massive transfusion before epidural insertion.

An upshot of war - damage control resuscitation

Management of battlefield casualties in Iraq and Afghanistan has seen considerable development in damage control resuscitation, which aims to address the risk of haemorrhage, initially due to mechanical damage; and thereafter due to the development of life-threatening coagulopathy. Damage control resuscitation combines a variety of techniques, such as the use of the combat application tourniquet and novel haemostatics, through to ground-breaking developments in transfusion protocols. These practical aspects of the doctrine are combined with an ethos which sees consultant-led care implemented from as close to the point of wounding as is possible. Meticulous trauma audit is included in this process and has allowed for rapid translation of knowledge into practice. The main elements of this doctrine are described.

Battlefield resuscitation

PURPOSE OF REVIEW

To bring together in one review article, the most current and relevant evidence relating to military trauma resuscitation.

RECENT FINDINGS

The main themes highlighted by this review are coagulopathy of trauma shock (CoTS), damage control resuscitation, haemostatic resuscitation, the management of massive transfusion, use of adjuvant drugs for haemostasis and use of an empiric massive transfusion protocol.

SUMMARY

The review aims to educate the readership in recent advances in trauma practice, culminating in a novel empiric massive transfusion algorithm seamlessly guiding the clinician through the initial resuscitation stage resulting in reduced mortality, morbidity, coagulopathy and decreased overall blood product usage.

Military pre-hospital care: why is it different?

There are significant differences between the civilian and military pre-hospital trauma systems relating to patient load, injury severity and the nature of the environment. This is reflected in differing clinical paradigm and treatment protocols. There is opportunity, however, for the two systems to learn from each other, which is particularly relevant at the time the UK is actively engaging with defining the requirement for trauma centres and the re-configuration of civilian trauma systems.

Lessons from the battlefield in the management of major trauma

Continuing the Journal's series of leading articles on trauma, Mr Streets of Bristol Royal Infirmary explains what civilian practitioners can learn from their military colleagues.