Article Text
Abstract
Background Despite the early uses of tourniquets and haemostatic dressings, blood loss still accounts for the vast majority of preventable deaths on the battlefield. Over the last few years, progress has been made in the management of such injuries, especially with the use of damage control resuscitation concepts. The early application of these procedures, on the field, may constitute the best opportunity to improve survival from combat injury during remote operations.
Data sources Currently available literature relating to trauma-induced coagulopathy treatment and far-forward transfusion was identified by searches of electronic databases. The level of evidence and methodology of the research were reviewed for each article. The appropriateness for field utilisation of each medication was then discussed to take into account the characteristics of remote military operations.
Conclusions In tactical situations, in association with haemostatic procedures (tourniquet, suture, etc), tranexamic acid should be the first medication used according to the current guidelines. The use of fibrinogen concentrate should also be considered for patients in haemorrhagic shock, especially if point-of-care (POC) testing of haemostasis or shock severity is available. If POC evaluation is not available, it seems reasonable to still administer this treatment after clinical assessment, particularly if the evacuation is delayed. In this situation, lyophilised plasma may also be given as a resuscitation fluid while respecting permissive hypotension. Whole blood transfusion in the field deserves special attention. In addition to the aforementioned treatments, if the field care is prolonged, whole blood transfusion must be considered if it does not delay the evacuation.
- War-Related Injuries
- Hemorrhage
- Fibrinogen
- Plasma
- Blood transfusion
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Key messages
In case of delayed evacuation, an application of ‘damage control resuscitation’ procedures constitutes the best opportunity to improve survival from combat injury.
Fibrinogen concentrate administration in the field should be considered for combat casualties in haemorrhagic shock.
Lyophilised plasma may be given as a resuscitation fluid while respecting permissive hypotension.
Fresh whole blood transfusion in the field (‘buddy transfusions’) can be considered but it requires prior careful consideration and specific training before being implemented.
The use of point-of-care testing can help to assess the severity of the shock to prioritise the patient who will benefit the most such interventions.
Introduction
Identifying a potential cause of death, applying life-saving treatments and evacuating casualties through coordinated action to a surgical facility, without loss of time, while continuing care are the cornerstones of modern combat casualty care (T Hodgetts. A revolutionary approach to improving combat casualty care. Unpublished Doctoral thesis, City University London, 2012;143p.).1 ,2 The vast majority of preventable deaths on the battlefield are still associated with blood loss.3 Despite the early use of tourniquets and haemostatic dressings, limb injuries still represent 13.5% of preventable deaths;4 ,5 stopping bleeding is, therefore, a priority for every single soldier. However, haemorrhage is not always compressible or controllable with tourniquets, and truncal and junctional injuries represent an important proportion of preventable causes of death.3 These injuries should ideally be treated during the first hour after the wound, or at least before the second hour, by a surgical team who will apply damage control surgery (DCS) and damage control resuscitation (DCR).6 These principles are nowadays the NATO standard for war injuries.7
The DCR concept is aimed at preventing or treating the lethal triad (hypothermia, acidosis, dilution).8 It combines control of the bleeding, protection against hypothermia, small volume resuscitation and aggressive treatment of the coagulopathy.9 ,10 However, in remote operational theatres, many tactical, environmental or logistic constraints make the application of this concept harder.
The goal of this review is to encourage further thought about the application of these procedures in the context of combat casualty care during remote operations, and especially to make suggestions regarding remote haemostasis and transfusion during tactical and prolonged field care. Of course, such procedures must not delay the evacuation to a medical treatment facility where surgical haemostasis can be processed, according to the DCS principles.
Methods
A search was performed of PubMed using the search terms trauma and prehospital, successively combined with the search terms coagulopathy, fibrinogen concentrates, prothrombin complex concentrates, tranexamic acid, plasma, whole blood, transfusion, point-of-care testing. Articles reporting data on combat casualties in remote settings were also identified from PubMed, using the search terms battlefield, tactical combat casualty care and special operation forces. Only articles written in French or in English were selected. The search covered articles published since 2000, even if few articles prior published have been finally cited.
Austere military environments
Features of remote military operations
A good example of remote military operations are Special Operations which refer to actions in which a small number of soldiers, discreetly deployed for a period of a few hours up to a few weeks, are carried out to obtain a crucial result in a hostile environment.11 Such operations are conducted in highly insecure areas with limited logistics support and require a small footprint and high mobility;7 ,12 accordingly, troops who conduct such operations may be more lightly equipped, especially in terms of ballistic protection. All of this may increase their vulnerability to ballistic trauma. Although special operations forces (SOF) usually conduct these operations, conventional forces may also work in small teams in remote areas and can be thus exposed to the same risks.
Specificities of casualties during remote operations
There are no specific data on casualties during remote operations, but analysis of the few data about SOF casualties in operations can be a way to observe a population of war casualties wounded in austere environments. The reports of the assault on the Punta Paitilla Airport in 1989 and on Mogadishu in 1993 show clearly the high intensity of combat and describe a large number of gunfire injuries.13 ,14 The accounts of the assault on Mogadishu also illustrate its remoteness and the consequences for the availability of medical evacuation—evacuations were delayed because of the tactical situation and seven medics managed 39 casualties for more than 14 hours before they could be evacuated. Among those killed in action, many were due to uncontrolled bleeding (thoracic, inguinal) who died several hours after injury, while others died after a delayed DCS procedure. Two recent studies15 ,16 report that in Iraq and Afghanistan, while explosions remain the most common cause of injury among US SOF soldiers, the proportion of fatal gunshot injuries in total causes of death seems to be bigger than among conventional forces.3 Kotwal et al15 described that none died of the previously reported three major causes of preventable death: haemorrhage from extremity wounds, tension pneumothorax and airway problems. Holcomb et al16 identified truncal bleeding as the most common preventable cause of death. The main cause of death during special operations seems currently to be related to gunshot wounds (GSWs) and uncontrollable bleeding, while the types of wounds depend mainly on the type of mission. Therefore, an early application of the DCR concept constitutes the best opportunity to improve survival from combat injury.15
Features of the required medical support
At Punta Paitilla, half of the casualties were injured trying to rescue their wounded comrades, trapped under fire showing the relevance of specific medical support.13 In such situations, the availability of medical evacuation is limited and the carers may have to select the medical equipment they take, in order to preserve their mobility. The medical support must be appropriate to the environment and the procedures applied must take into account all the mission objectives, the seriousness of the injuries and the safety of the casualties and the responders. This differentiates soldiers from the counter-terrorism and hostage rescue teams of police departments, who can quickly count on the civilian heath service close to the hot zone. In French forces, including SOF, the decision was made to place physicians and nurses in the field, with the soldiers, in order to take care of the casualties as soon as possible. They must be specifically trained, medically as well as tactically, to be suitable for the missions that their units carry out.
Haemostatic resuscitation
In austere environments where evacuation can easily be delayed, early control of bleeding injuries and management of trauma-induced coagulopathy (TIC) appear to be crucial. This is achieved through the application in the field of haemostatic resuscitation procedures called ‘remote DCR’17 or ‘tactical DCR’.18
Trauma-induced coagulopathy
Overall, 20–30% of injured patients have a coagulopathy, which is complex and multifactorial.19 ,20 With regard to combat casualties, patients injured by explosion seem to have more coagulopathy than those injured by GSWs, even with similar Injury Severity Scores.21 It involves exogenous (eg, dilution) and endogenous mechanisms. Endogenous mechanisms are related to tissue hypoperfusion and tissue factor release and are thought to be responsible for the installation of an early anticoagulation state and hyperfibrinolysis through the activation of the protein C pathway.22 ,23 Furthermore, hypothermia induces platelet dysfunction and reduces the coagulation enzyme activity, particularly in the case of acidosis, also affecting the coagulation system.24–26 All these mechanisms (endogenous and exogenous) cause a slower formation of a more fragile blood clot, which can increase the bleeding. TIC represents an independent factor for mortality.27 ,28
A decrease of all the coagulation factors is observed, but is especially significant in the case of fibrinogen;29 ,30 a fibrinogen deficit is observed in 14–26% of all seriously injured patients.31 ,32 This decrease occurs early after a severe trauma even before any fluid administration.33 ,34 It is mainly related to consumption (fibrinolysis) and blood loss, but each element of the lethal triad (acidosis, hypothermia and dilution) can independently increase the fibrinogen deficit.35
Medication for TIC
Stopping the bleeding requires a strategy involving prehospital haemostasis, early surgery and adequate resuscitation. The aim of this resuscitation is to manage the lethal triad elements, especially the coagulopathy. In austere military environments, it seems necessary to think about the use of haemostatic treatment (including tranexamic acid (TXA)) at the point of injury, at the regimental aid post or during the evacuation.
Tranexamic acid
In total, 3–8% of trauma casualties are in a state of severe hyperfibrinolysis and almost 60% have moderate hyperfibrinolysis.36 The CRASH-2 study has shown a decrease in mortality with the administration of TXA if administered within the first 3 hours following the injury.37 ,38 Moreover, TXA is cheap, not altered by extreme temperatures39 and remains efficient even in the face of acidosis.40 Widely used in civilian health systems, TXA has proven its benefit on the battlefield with the MATTERs study41 and is nowadays part of the tactical combat casualty care.4 ,42
Lyophilised plasma
Early use of fresh frozen plasma (FFP) in a 1:1 ratio with red blood cells units increases the survival rate of massively transfused patients, independently of other administered blood products.43–46 This approach has also been validated in military settings.47 ,48 It has become common practice for penetrating trauma care in the USA.49 Adverse effects (multiorgan failure, acute respiratory distress or venous thromboembolism) have been reported after administration of plasma, but mainly in patients not requiring a massive transfusion.50–52 In massively transfused combat casualties, an increase in the risk of acute respiratory distress has not been reported after plasma administration.53 There is no doubting the benefit of plasma administration in massively transfused patients.
In hospitals, the most frequently used plasma is FFP, which needs time to be thawed and then transported to the trauma resuscitation unit. The French Military Health Service has developed a substitute: French lyophilised plasma (FLYP). FLYP is as effective as FFP for improving thrombin generation and clot formation.54 ,55 It is safe in terms of haemovigilance56 ,57 and follows all the regulatory and sanitary developments. Its use in civilian practice is now allowed and recommended by the French Agency for Medication Safety (Agence Nationale de Sécurité du Médicament et des produits de santé).58 Its effectiveness has been shown in combat-injured patients at the French Role 3 Medical Treatment Facility in Kabul.59
FLYP is easy to use in the field. Quickly available, its reconstitution requires <6 min.57 Produced from several donors, by the Centre de Transfusion Sanguine des Armées, it is ABO-universal, and thus compatible with all blood groups. The natural antibodies anti-A and anti-B are diluted and neutralised during the plasma selection for the compound. It is storable for 2 years at room temperature. In real-life conditions (Operation Barkhane), it has been shown that after 3 months of storage at temperatures ranging from 28°C to 53°C, 55% of the fibrinogen activity persisted.60 Lyophilised plasma has already been used during prehospital care, notably in Norway and Israel.17 ,61 In the Israeli military experience, lyophilised plasma is used early, at the point of injury, as the primary resuscitation fluid, when the injury mechanism suggests a massive haemorrhage, in patients with a systolic BP below 80 mm Hg (or an absent radial pulse); this is the ‘plasma first’ concept and has already been applied a few dozen times, without reported adverse events. In 2014, the USA introduced the early use of lyophilised plasma in the TCCC.42
In summary, there is sufficient evidence to support the early use of the lyophilised plasma, at the point of injury, as soon as it is available, as a resuscitation fluid with hypotensive resuscitation principles for patients with haemorrhagic shock.
Fibrinogen concentrates
Fibrinogen deficit plays an important part in TIC, and a low fibrinogen level is associated with larger blood loss and the need for transfusion.31 Experimental data suggest that the administration of fibrinogen concentrates reduces blood loss in dilutional coagulopathy.62 In other settings such as cardiac surgery, the use of fibrinogen concentrate was associated with a reduction in allogeneic blood products transfusions.63 The use of fibrinogen concentrates appears to be safe, with no significant adverse effects.10 ,64 ,65 To be most effective, an early administration of fibrinogen would be better.31 ,34 Treatment with fibrinogen is actually recommended in the presence of thromboelastometric signs of a functional fibrinogen deficit or a plasma fibrinogen level of <1.5 g/L.66 ,67 With regard to combat casualties, a retrospective study, conducted in a Role 3 Medical Treatment Facility, showed that a transfusion of an increased fibrinogen-to-red blood cell ratio was independently associated with improved survival.68
Fibrinogen is found in FFP and cryoprecipitate, but it has been shown that the best source of fibrinogen is provided by fibrinogen concentrate.69 Like FLYP, fibrinogen concentrate is easy to use in the field, is quickly available and is storable at room temperature. However, the benefits of fibrinogen supplementation in prehospital settings, without any prior lab test, have not yet been proved. Multicentric prospective investigations are currently underway with the ‘FIinTIC study’,65 but it will take months before their results are published. Nevertheless, for wounded soldiers presenting with haemorrhagic shock, who cannot be quickly evacuated, and thus treated by an hospital before a long time, it seems reasonable to treat them with fibrinogen concentrates in the field, all the more since an early administration seems to be required to improve outcomes. The prognosis of such a patient in the field is so poor that the risk/benefit balance supports this use.
Prothrombin complex concentrates
Prothrombin complex concentrates (PCCs) are concentrates of vitamin K-dependent coagulation factors (X, IX, VII, II), which induce a rapid and important increase of thrombin generation. These products are designed to rapidly reverse the action of vitamin K antagonists in the case of bleeding or urgent surgery.70 ,71
Many teams have explored the use of PCCs in the treatment of TIC, but clinical evidence is still lacking to definitively validate its use. Joseph et al72 ,73 have shown, in patients with trauma, a more rapid correction of the internationalised normalised ratio (INR) and less need for blood products by using PCCs and FFP together compared with FFP alone. In another study, a reduction in the need for blood products, with a similar mortality rate, was described in patients with trauma when injured patients received fibrinogen concentrates and PCCs in comparison with those receiving only FFP.74 In pre-hospital settings, the only reported cases involve antagonisation of prior vitamin-k anticoagulant therapy.75 ,76 Currently, the use of PCCs is advocated only in cases of prior anticoagulation treatment or in the case of severe bleeding if FFP is not rapidly available;66 ,67 moreover, PCCs need to be stored at 4°C, which limits its use in the field.
Avenues for research
Products currently under development include lyophilised platelets and red blood cells; another path of research is the administration of a ‘one-shot’ solution containing 7.5% NaCl with adenosine, lidocaine and magnesium, which seems to increase survival and correct TIC in experimental studies. The mechanism is still poorly understood and the assumption is that this solution would decrease the protein C activation through the thrombomodulin–thrombin complex.77 ,78
Far-forward blood transfusion
A large improvement in mortality can be achieved by an aggressive approach to DCR, including the use of prehospital transfusion,79 ,80 and studies have therefore been conducted to bring packed red blood cells (PRBCs) into the field in isothermal packaging. United Kingdom medical emergency response team - enhanced (UK MERT-E) teams safely implemented en route prehospital blood transfusion (PRBCs and thawed FFP).81 Boscarino et al82 also demonstrated in a parachute drop and a 12-hour mission model that carrying blood packs into the SOF environment does not alter PRBCs, which withstand extreme heat and preserve their biochemical qualities. However, because of the unpredictable nature of missions, this may not be applicable to longer missions or different physical stresses. Implementation of such a ‘golden blood box’ may be impossible. Aye Maung et al83 have reported two cases of successfully resuscitated wounded soldiers who required transfusion during more than 1000 mission hours and showed that if an isolated Role 1 regular medical team can safely deliver blood transfusion by vehicle, helicopter or foot patrols, it was associated with a large logistical burden. They also pointed out that it was for a relatively small clinical output.
Nowadays whole blood transfusion is accepted for early treatment of oxygen debt and traumatic coagulopathy.84–86 It will provide the patient, in addition to clotting factors, with red blood cells87 and moreover, for many nations, it represents the only source of platelets in an operational theatre. It has been shown that cold-stored whole blood regularly carried in isothermal containers preserves its clotting factors for at least 2 weeks.88 Nevertheless, this concept requires huge logistic organisation, anticipation of blood product requirements and many donors to frequently replenish the stocks.
In the special operations context, the concept of ‘buddy transfusion’ has reappeared and is about collecting whole blood from an uninjured combat companion and transfusing it warm in field conditions. This concept has the advantage of always having available fresh whole blood, maintained indefinitely at 37°C and without storage constraints or much extra equipment. It is currently being considered by United States Special Operations Command (USSOCOM), Norwegian, Canadian and British troops.18 ,89–91
The procedure for fresh whole blood transfusion in the field needs to be anticipated with the selection and education of donors. Blood collection, compatibility tests and surveys of both wounded soldiers and donors are time-consuming procedures. It is important to state that one of the most common complications is an inability to use the collected blood because the bag is not full enough (approximately 15% incidence).92 Moreover, because of the limited number of soldiers that will be used as walking blood banks, only a few whole blood packs will be available for use in the field or for en route transfusion therapy.
Remote transfusion, however, leads to risks. First, the risk of errors in matching donors and recipient blood types appears to be high in this austere and stressful context of combat. Controlling this risk requires the prior identification of donors and the use of a control system before the collected blood is transfused, such as an ultimate control chart with predried reagent. It is also conceivable to identify, even before the deployment, ‘universal donors’, which are Group O soldiers, with low titres of anti-A and anti-B antibodies. Fresh whole blood would be collected preferably from those donors in the case of necessity. This last approach is attractive, but seems limited by the scarcity of such donors, especially when operators work in small teams.
The risk of transfusion-transmitted diseases seems to be controllable through potential donor education, routine predeployment testing for viral diseases of concern, pre-donation examination and rapid viral diagnostic tests realisable in the field.
The Norwegian Naval Special Operation Commandos have shown, in experimental conditions, that buddy transfusion is feasible, safe for the donor and does not decrease donor combat performance in ideal circumstances in simulated combat.93 Thus, they have developed a training programme and have shown the feasibility of the collection of fresh whole blood by specifically trained medics.89
However, only some case reports have been published and there is no strong evidence of the effectiveness of early fresh whole blood transfusion on the battlefield with the studies only indicating the feasibility of such an approach.87 ,94 ,95 Questions still remain regarding the composition of blood collected from soldiers after hours of combat in austere environments. Furthermore, many remote military operations are conducted by small groups of soldiers, and a legitimate concern is whether a compatible donor will be available near an injured soldier. Moreover, the amount of blood taken from a soldier on the battlefield will be limited by necessity, since the soldier will have to pursue the mission and eventually fight. Fresh whole blood transfusion will also have to be considered only when there is a significant probability of evacuation to a surgical facility for haemorrhage control in a reasonable time.
Prior careful consideration, protocols for collection and transfusion in the field and specific training are thus warranted, before implementing such a transfusion strategy.
Protocol proposal
Identifying haemorrhagic shock
An early application of the remote DCR concept constitutes the best opportunity to improve survival from combat injury—the diagnosis of haemorrhagic shock is therefore a crucial step. Its recognition should be based on haemodynamic criteria and, if available, on biological measures (haemoglobinaemia, haematocrit, pH, INR). In a tactical context, in the presence of a penetrating trauma with obvious bleeding, it is therefore acceptable to use simple clinical signs, such as an absent or weak radial pulse, an altered mental status and the response to fluid administration, to evaluate the severity of a haemorrhagic shock; such an approach has been recently validated in a pre-hospital study with 91% specificity.96
Nevertheless, the use of point-of-care (POC) testing can be helpful for quickly determining haemoglobin, lactate or the INR and thus may help in better assessing the severity of the shock and/or the coagulopathy, in addition to clinical signs. Furthermore, in tactical settings, with limited available resources, in the case of several casualties, such POC devices may help to prioritise the injured patient who will benefit the most from haemostatic medication.
Currently, lactate is easily and reliably measurable in the field.97 It has been shown that lactate blood level is a severity marker of haemorrhagic shock, and nowadays it is recommended that its level should be monitored in the management of haemorrhagic shock.66 However, there are some concerns about the pertinence of lactate levels for the evaluation of shock severity during combat. Lactate levels rise naturally when significant exercise is performed, and levels as high as 12 mmol/L can be observed in combat scenarios.93 To overcome this limitation, in the case of doubt, it is suggested that lactate capillary levels should be measured a second time, 15–20 min later, in order to establish a trend line. Lactate <5 mmol/L, stable or falling, suggests acceptable tissue oxygenation.18
Base deficit (BD) is also a valuable predictor of massive transfusion and mortality in patients with traumatic haemorrhagic shock. The last European guideline recommends measuring it in association with lactate to estimate and monitor the extent of bleeding and shock.66 A BD of 6 mmol/L appears as a threshold to identify patient who will need an emergent transfusion.98 ,99 POC BD testing is available, with good correlation with lab tests.100 ,101 Nevertheless, as other POC testing, such devices cannot work in extreme temperatures.102 ,103 Outside the required temperature range of 16–30°C, the unit ceases to operate and displays a message indicating the unit’ s temperature is out of range.
INR measurement using a POC device also appears helpful in identifying TIC in bleeding patients with trauma without prior anticoagulant therapy. It has been identified as one of the strongest predictors of the need for massive transfusion in both civilian and military populations.104–106 Many authors suggest to use an increased prothrombin ratio as a definition of coagulopathy, although the cut-off value to define the coagulopathy is still debated with values of 1.2 and 1.5 suggested22 ,107 with 1.2 seeming more appropriate for the field care context. POC INR testing is nowadays well assessed and allows safe self-monitoring of oral anticoagulation108 ,109 but its use is still under discussion for patients with trauma110 although several teams have reported a good correlation between POC testing and laboratory testing in such situations.111 ,112 A study in a Level 1 trauma centre has shown that POC INR performed in the emergency department could predict massive transfusion.113 One major limitation is that INR rises belatedly during haemorrhagic shock; furthermore, POC INR testing could be less accurate in cases of coagulopathy and for low values.22 In case of obvious haemorrhagic shock, waiting for high POC INR reading before use of haemostatic drugs would be a mistake. A recent prehospital study has reported the feasibility of the use of POC INR testing in prehospital settings114 although technical difficulties have frequently occurred in cases of outdoor temperatures below 5°C or higher than 35°C, or when blood was applied later than 2 min after venepuncture. These requirements could make such POC INR testing unusable during military operations, especially in warm areas.
As POC testing can easily fail to identify coagulopathy, or may be unavailable in the field, it must be only considered as an adjunct and in such situations, the clinical sense of the carers remains essential in order to identify patients who require this protocol.
Specific considerations
Haemostatic resuscitation involves the very early use of blood and blood products as primary resuscitation fluids to treat acute traumatic coagulopathy and shock. Nevertheless, tactical situation and logistical difficulties, as encountered in austere military environments, strongly limit the implementation of standard haemostatic protocols. It is thus necessary to design haemostatic resuscitation protocols that are applicable on the battlefield, taking into account both the therapeutic needs and the tactical context. Therefore, efficiency, simplicity and safety are major concerns. In this context, tools to control external haemorrhage (tourniquets, junctional haemorrhage control tools, wound packing, suture, haemostatic dressings, etc) and TXA will play a major role.115
The use of blood components in the field should also be considered. FLYP ensures both coagulation factors and volume replacement and has a favourable safety profile. Despite a certain bulkiness, it might be available for tactical use, especially in cases of prolonged field care and/or delayed medical evacuation. Like FLYP, fibrinogen concentrate is easy to store and reconstitute, may be conserved at ambient temperature and probably represents a better bulkiness profile for dismounted operations such as long-range pedestrian, airborne or nautical infiltration. Blood transfusion in the field is now considered a feasible life-saving procedure when facing significant haemorrhage, but it has logistic constraints. Warm fresh whole blood transfusion (buddy transfusions) can be considered as an approach to ideal transfusion therapy in the field—for French forces, it is the only source of blood on the battlefield at Role 1. It requires prior specific training.
Protocol proposal
We suggest a protocol based on an analysis of the mechanism of injury, clinical evaluation and whether POC testing is available or not (Figure 1), but without recommendation of a specific resuscitation fluid as there isn't an ideal one. Colloids enable a faster and more persistent volume expansion than crystalloids, but must be used within the prescribed limits for each solution and their administration could be associated with side effects (acute kidney injury, impaired coagulation).116 Crystalloids are thus often applied initially, but large volumes of isotonic saline can induce hyperchloraemic acidosis,117 coagulopathy118 and increased mortality rates;119 furthermore, Ringer lactate is hypotonic. The more recent balanced fluids seem promising, but evidence of their clinical relevance is lacking. In practice, in a remote setting with limited medical supply, carers will use the fluids they have brought with them; hypertonic saline is thus often used because it offers the advantage of a small logistical burden.
The protocol also mentions the administration of vasopressors as a way to reach target arterial pressure in situations where severe hypotension persists despite fluid resuscitation in line with the most recent European guideline, even when fluid expansion is in progress and hypovolaemia has not yet been corrected.66 However, the effect on microcirculation is much more uncertain, and some authors suggest that vasopressor use may increase mortality;120 ,121 thus the aim would be to minimise exposure to vasopressors, but if used to aim for a target systolic arterial pressure of 80–90 mm Hg in patients without traumatic brain injury. In such a limited resource context like remote military operations, where there can easily be a lack of fluid supply, vasopressors can be useful. We propose a three-step model approach to achieving control of haemorrhage:
First step: initial life-saving interventions including external haemostasis and hypothermia prevention, first dose of TXA, fluid administration according to hypotensive resuscitation principles and the use of a vasopressor—these are performed along with careful monitoring of the haemorrhage. If there are no signs of severity, prepare the patient for evacuation.
Second step: signs of severity are detected and/or the bleeding persists. Check external haemorrhage control. Administration of a second dose of TXA. Consider administration of fibrinogen concentrate. The decision to administrate it is based on clinical arguments, but if POC testing is available, it can help the decision-making, if lactate ≥5 mmol/L and/or INR ≥1.2 and/or BD ≥6 mmol/L. In this limited available resources context, it is important to identify with certainty casualties who do require such medications and to prioritise the wounded patient who will benefit the most from such medications in the case of several casualties. At this stage, FLYP should be considered as a resuscitation fluid, if it is available, according to the plasma first concept.
Third step: if despite steps one and two bleeding persists with signs of severe shock and/or lactate ≥5 mmol/L and/or INR ≥1.2 and/or BD ≥6 mmol/L, consider fresh whole blood transfusion, according to the tactical context, without delaying the evacuation.
Clinical judgement should remain central to the decision process.
Conclusion
Enabling combat casualties to benefit from the latest scientific advances in the area of haemostatic resuscitation in the field is a priority. We propose an approach, essentially based on clinical judgement, to identify wounded soldiers who need haemostatic resuscitation management and in our view, the risk/benefit balance supports this protocol. Indeed, for bleeding traumatised patients, an early application of the haemostatic resuscitation concept could clearly improve their survival chances. The French concept of battlefield medical support, which is physician based, allows such an approach, but prolonged field care can also be enhanced through remote supervision.
References
Footnotes
Contributors YD drafted the manuscript. YD, SH, LM and SP collected data and analysed them. JE, J-SD and SP critically revised the manuscript.
Competing interests J-SD did lectures for LFB Laboratory (Les Ullis, France).
Provenance and peer review Not commissioned; externally peer reviewed.