Tourniquets: A Review of Current Use with Proposals for Expanded Prehospital Use

Implementing Tourniquet Conversion Guidelines for Civilian EMS and Prehospital Organizations : A Case Report and Review

Since the first documented use of a tourniquet in 1674, the popularity of tourniquets has waxed and waned. During recent wars and more recently in Emergency Medical Services systems, the tourniquet has been proven to be a valuable tool in the treatment of life-threatening hemorrhage. However, tourniquet use is not without risk, and several studies have demonstrated adverse events and morbidity associated with tourniquet use in the prehospital setting, particularly when left in place for more than 2 h. Consequently, the US military's Committee on Tactical Combat Casualty Care has recommended guidelines for prehospital tourniquet conversion to reduce the risk of adverse events associated with tourniquets once the initial hemorrhage has been controlled. Emergency Medical Services systems that operate in rural, frontier, and austere environments, especially those with transport times to definitive care that routinely exceed 2 h, may consider implementing similar tourniquet conversion guidelines.

A randomized controlled trial comparison of PTEBL and traditional teaching methods in "Stop the Bleed" training

BACKGROUND

The Stop the Bleed (STB) training program was launched by the White House to minimize hemorrhagic deaths. Few studies focused on the STB were reported outside the United States. This study aimed to evaluate the effectiveness of a problem-, team- and evidence-based learning (PTEBL) approach to teaching, compared to traditional teaching methods currently employed in STB courses in China.

METHODS

This study was a parallel group, unmasked, randomised controlled trial. We included third-year medical students of a five-year training program from the Xiangya School of Medicine, Central South University who voluntarily participated in the trial. One hundred fifty-three medical students were randomized (1:1) into the PTEBL group (n = 77) or traditional group (n = 76). Every group was led by a single instructor. The instructor in the PTEBL group has experienced in educational reform. However, the instructor in the traditional group follows a traditional teaching mode. The teaching courses for both student groups had the same duration of four hours. Questionnaires were conducted to assess teaching quality before and after the course. The trial was registered in the Central South University (No. 2021JY188).

RESULTS

In the PTEBL group, students reported mastery in three fundamental STB skills-Direct Finger Compression (61/77, 79.2%), Packing (72/77, 93.8%), and Tourniquet Placement (71/77, 92.2%) respectively, while 76.3% (58/76), 89.5% (68/76), and 88.2% (67/76) of students in the traditional group (P > 0.05 for each pairwise comparison). 96.1% (74/77) of students in the PTEBL group felt prepared to help in an emergency, while 90.8% (69/76) of students in the traditional group (P > 0.05). 94.8% (73/77) of students reported improved teamwork skills after the PTEBL course, in contrast with 81.6% (62/76) of students in the traditional course (P = 0.011). Furthermore, a positive correlation was observed between improved clinical thinking skills and improved teamwork skills (R = 0.82, 95% CI: 0.74-0.88; P < 0.001).

CONCLUSIONS

Compared with the traditional teaching method, the PTEBL method was superior in teaching teamwork skills, and has equally effectively taught hemostasis techniques in the emergency setting. The PTEBL method can be introduced to the STB training in China.

Tourniquet Use in the Prehospital Setting

PURPOSE

Tourniquets are a mainstay of life-saving hemorrhage control. The US military has documented the safety and effectiveness of tourniquet use in combat settings. In civilian settings, events such as the Boston Marathon bombing and mass shootings show that tourniquets are necessary and life-saving entities that must be used correctly and whenever indicated. Much less research has been done on tourniquet use in civilian settings compared to military settings. The purpose of this study is to describe the prehospital use of tourniquets in a regional EMS system served by a single trauma center.

METHODS

All documented cases of prehospital tourniquet use from 2015 to 2020 were identified via a search of EMS, emergency department, and inpatient records, and reviewed by the lead investigator. The primary outcomes were duration of tourniquet placement, success of hemorrhage control, and complications; secondary outcomes included time of day (by EMS arrival time), transport interval, extremity involved, who placed/removed the tourniquet, and mechanism of injury.

RESULTS

Of 182 patients with 185 tourniquets applied, duration of application was available for 52, with a median (IQR) of 43 (56) minutes. Hemorrhage control was achieved in all but two cases (96%). Three cases (5.8%) required more than one tourniquet. Complications included five cases of temporary paresthesia, one case of ecchymosis, two cases of fasciotomy, and two cases of compression nerve injury. The serious complication rate was 7.7% (4/52). Time of day was daytime (08:01-16:00) = 15 (31.9%), evening (16:01-00:00) = 27 (57.4%), and night (00:01- 08:00) = 5 (10.6%). The median transport interval was 22 (IQR 5] minutes. The limbs most often injured were the left and right upper extremities (15 each). EMS clinicians and police officers were most often the tourniquet placers. Common mechanisms of injury included gunshot wounds, motorcycle accidents, and glass injuries.

CONCLUSION

Tourniquets used in the prehospital setting have a high rate of hemorrhage control and a low rate of complications.

Brief Training of Technical Bleeding Control Skills-A Pilot Study with Security Forces

Uncontrolled external bleeding is a common cause of preventable death, and due to the environment in which these events often occur, e.g., in hostile environments, the state security forces are usually the first responders, and in many cases, if they are injured their partners provide the initial assistance. The tourniquet is a fast, effective, and easy-to-learn intervention, although there is a knowledge gap concerning training techniques. The objective is to evaluate the effectiveness of a bleeding control training program on a high-fidelity mannequin in a simulated critical situation in a law enforcement training environment. A quasi-experimental study was carried out with 27 members of the state security forces. They underwent brief theoretical-practical training and were evaluated via a scenario involving a critically ill patient in a hostile environment. The results showed that no member of the state security forces completed all the tourniquet placement steps, 26 (96%) prepared the tourniquet correctly, 21 (77.8%) placed it on the leg, and all the participants adjusted the band to the thickness of the injured limb and secured the windlass to the triangular flange of the device. However, only 23 (85.2%) of the participants placed it effectively. The participants, who were members of the state security forces, were able to effectively resolve a critical situation with active bleeding in a simulation scenario with a high-fidelity mannequin after completing theoretical-practical training.

Impact of time and distance on outcomes following tourniquet use in civilian and military settings: A scoping review

BACKGROUND

The last two decades have seen the reintroduction of tourniquets into guidelines for the management of acute limb trauma requiring hemorrhage control. Evidence supporting tourniquet application has demonstrated low complication rates in modern military settings involving rapid evacuation timeframes. It is unclear how these findings translate to patients who have prolonged transport times from injury in rural settings. This scoping review investigates the relationship between time and distance on metabolic complications, limb salvage and mortality following tourniquet use in civilian and military settings.

METHODS

A systematic search strategy was conducted using PubMed, Embase, and SafetyLit databases. Study characteristics, setting, mechanism of injury, prehospital time, tourniquet time, distance, limb salvage, metabolic response, mortality, and tourniquet removal details were extracted from eligible studies. Descriptive statistics were recorded, and studies were grouped by ischemia time (< 2 h, 2-4 h, or > 4 h).

RESULTS

The search identified 3103 studies, from which 86 studies were included in this scoping review. Of the 86 studies, 55 studies were primarily in civilian environments and 32 were based in military settings. One study included both settings. Blast injury was the most common mechanism of injury sustained by patients in military settings (72.8% [5968/8200]) followed by penetrating injury (23.5% [1926/8200]). In contrast, in civilian settings penetrating injury was the most common mechanism (47.7% [1633/3426]) followed by blunt injury (36.4% [1246/3426]). Tourniquet time was reported in 66/86 studies. Tourniquet time over four hours was associated with reduced limb salvage rates (57.1%) and higher mortality rates (7.1%) compared with a tourniquet time of less than two hours. The overall limb salvage and mortality rates were 69.6% and 6.7% respectively. Metabolic outcomes were reported in 28/86 studies with smaller sample sizes and inconsistencies in which parameters were reported.

CONCLUSION

This scoping review presents literature describing comparatively safe tourniquet application when used for less than two hours duration. However, there is limited research describing prolonged tourniquet application or when used for protracted distances, such that the impact of tourniquet release time on metabolic outcomes and complications remains unclear. Prospective studies utilizing the development of an international database to provide this dataset is required.

Administration of particulate oxygen generators improves skeletal muscle contractile function after ischemia-reperfusion injury in the rat hindlimb

Extended tourniquet application, often associated with battlefield extremity trauma, can lead to severe ischemia-reperfusion (I/R) injury in skeletal muscle. Particulate oxygen generators (POGs) can be directly injected into tissue to supply oxygen to attenuate the effects of I/R injury in muscle. The goal of this study was to investigate the efficacy of a sodium percarbonate (SPO)-based POG formulation in reducing ischemic damage in a rat hindlimb during tourniquet application. Male Lewis rats were anesthetized and underwent tourniquet application for 3 h at a pressure of 300 mmHg. Shortly after tourniquet inflation, animals received intramuscular injections of either 0.2 mg/mL SPO with catalase (n = 6) or 2.0 mg/mL SPO with catalase (n = 6) directly into the tibialis anterior (TA) muscle. An additional Tourniquet-Only group (n = 12) received no intervention. Functional recovery was monitored by in vivo contractile testing of the hindlimb at 1, 2, and 4 wk after injury. By the 4 wk time point, the Low-Dose POG group continued to show improved functional recovery (85% of baseline) compared with the Tourniquet-Only (48%) and High-Dose POG (56%) groups. In short, the low-dose POG formulation appeared, at least in part, to mitigate the impact of ischemic tissue injury, thus improving contractile function after tourniquet application. Functional improvement correlated with maintenance of larger muscle fiber cross-sectional area and the presence of fewer fibers containing centrally located nuclei. As such, POGs represent a potentially attractive therapeutic solution for addressing I/R injuries associated with extremity trauma.NEW & NOTEWORTHY Skeletal muscle contraction was evaluated in the same animals at multiple time points up to 4 wk after injury, following administration of particulate oxygen generators (POGs) in a clinically relevant rat hindlimb model of tourniquet-induced ischemia. The observed POG-mediated improvement of muscle function over time confirms and extends previous studies to further document the potential clinical applications of POGs. Of particular significance in austere environments, this technology can be applied in the absence of an intact circulation.

Hyperbaric oxygen therapy does not alleviate tourniquet-induced acute ischemia-reperfusion injury in mouse skeletal muscles

During tourniquet application, blood flow is restricted to a limb to stop excessive limb hemorrhage in a trauma setting and to create a bloodless operating field in the surgical setting. During tourniquet-related ischemia, aerobic respiration stops, and ATP is depleted, and during subsequent reperfusion, there is an increase in reactive oxygen species (ROS) production and other endogenous substances, which leads to acute ischemia-reperfusion (IR) injuries, including tissue necrosis and skeletal muscle contractile dysfunction. Hyperbaric oxygen (HBO) therapy can increase the arterial oxygen tension in the tissues of patients with general hypoxia/anoxia, including carbon monoxide poisoning, circulatory arrest, and cerebral and myocardial ischemia. Here, we studied the protective effects of HBO pretreatment with 100% oxygen at 2.5 ATA against tourniquet/IR injury in mice. After one hour of HBO therapy with 100% oxygen at 2.5 ATA was administered to C57/BL6 mice, a rubber band was placed at the hip joint of the unilateral hindlimb to induce 3 h of ischemia and then released for 48 h of reperfusion. We analyzed gastrocnemius muscle morphology and contractile function and measured the levels of ATP and ROS accumulation in the muscles. HBO pretreatment did not improve tourniquet/IR-injured gastrocnemius muscle morphology and muscle contraction. Tourniquet/IR mice with HBO pretreatment showed no increase in ATP levels in IR tissues, but they did have a decreased amount of ROS accumulation in the muscles, compared to IR mice with no HBO pretreatment. These data suggest that one hour of HBO pretreatment with 100% oxygen at 2.5 ATA increases the antioxidant response to lower ROS accumulation but does not increase ATP levels in IR muscles and improve tourniquet/IR-injured muscle morphology and contractile function.

Prolonged tactical tourniquet application for extremity combat injuries during war against terrorism in the Sahelian strip

PURPOSE

This study reports on complications following extended tourniquet application in patients with combat extremity injuries treated by the French Military Health Service in the Sahelian strip.

METHODS

A retrospective review was performed in a French forward medical treatment facility deployed in Gao, Mali, between 2015 and 2020. All patients treated for an extremity injury with the application of at least one tourniquet for a minimum of 3 h were included. Prehospital data were injury pattern, associated shock, tourniquet location, and duration. Subsequent complications and surgical procedures performed were analyzed.

RESULTS

Eleven patients with a mean age of 27.4 years (range 21-35 years) were included. They represented 39% of all patients in whom a tourniquet was applied. They had gunshot wounds (n = 7) or multiple blast injuries (n = 4) and totaled 14 extremity injuries requiring tourniquet application. The median ISS was 13 (interquartile range: 13). Tourniquets were mostly applied proximally on the limb for a mean duration of 268 min (range 180-360 min). Rhabdomyolysis was present in all cases. The damage control surgeries included debridement, external fixation, vascular repair, and primary amputation. Ten injuries were complicated by compartment syndrome requiring leg or thigh fasciotomy in the field or after repatriation. Two severely injured patients died of their wounds, but the others had a favorable outcome even though secondary amputation was sometimes required.

CONCLUSIONS

Extended and proximal tourniquet applications led to significant morbidity related to compartment syndrome and rhabdomyolysis. Hemorrhagic shock, mass casualty incident, and tactical constraints often precluded revising the temporary tourniquet applied under fire.

A comparison of acute mouse hindlimb injuries between tourniquet- and femoral artery ligation-induced ischemia-reperfusion

The tourniquet or femoral artery ligation is widely used to stop extremity hemorrhage or create a bloodless operating field in the combat scenario and civilian setting. However, these procedures with subsequent reperfusion also induce ischemia-reperfusion (IR) injuries. To fully evaluate animal models of limb IR injuries, we compared tourniquet- and femoral artery ligation-induced IR injuries in the hindlimb of mice. In C57/BL6 mice, 3 h of unilateral hindlimb ischemia was induced by placement of a rubber band at the hip joint or a surgical ligation of the femoral artery. The tourniquet or femoral artery ligation was then released, allowing for 24 h of reperfusion. Compared to the femoral artery ligation/IR, the tourniquet/IR induced more severe skeletal muscle damage, including muscle necrosis and interruption of muscle fibers. There was no gastrocnemius muscle contraction in tourniquet/IR, while femoral artery ligation/IR markedly weakened gastrocnemius muscle contraction. Motor nerve terminals disappeared, and endplate potentials (EPPs) were undetectable in tourniquet/IR, whereas femoral artery ligation/IR only induced mild impairment of motor nerve terminals and decreased the amplitude of EPPs. Additionally, western blot data showed that proinflammatory cytokine levels (IL-1β and TNF-α) were higher in the tourniquet/IR than that in femoral artery ligation/IR. Moreover, tourniquet/IR caused significant tissue edema and dilation of lymphatic vessels in the hindlimb, compared to femoral artery ligation/IR. The above data demonstrated that tourniquet/IR-induced acute hindlimb injuries are more severe than those induced by femoral artery ligation/IR. This suggests that future investigators should determine which hindlimb IR model (tourniquet/IR or femoral artery ligation/IR) is optimal depending on the purpose of their study.

Teaching and Evaluation Methods of the Use of the Tourniquet in Severe Limb Bleeding among Health Care Professionals: A Systematic Review

INTRODUCTION AND OBJECTIVES

Massive hemorrhage (MH) is a growing pathology in military settings and increasingly in civilian settings; it is now considered a public health problem in the United States with large-scale programs. Tourniquets are the fastest and most effective intervention in MH if direct pressure is not effective.The Liaison Committee on Resuscitation (ILCOR) recognizes a knowledge gap in optimal education techniques for first aid providers. This review aims to describe training and evaluation methods for teaching tourniquet use to both health care and military professionals.

METHODS

The MEDLINE, CINAHL, WEB of Science, and Scopus databases were reviewed (from 2010 through April 2020). The quality of the selected studies was assessed using the Consolidated Standards of Reporting Trials (CONSORT) scale. Studies that met at least 65% of the included items were included. Data were extracted independently by two reviewers.

RESULTS

Ten of the 172 articles found were selected, of which three were randomized clinical trials. Heterogeneity was observed in the design of the studies and in the training and evaluative methods that limit the comparison between studies.

CONCLUSIONS

The results suggest that the training strategies studied are effective in improving knowledge, attitudes, and practical skills. There is no universal method, learning is meaningful but research should be directed to find out which ones work best.

Relationship Between Interface Pressures and Pneumatic Cuff Inflation Pressure at Different Assessment Sites of the Lower Limb to Aid Soft Exoskeleton Design

OBJECTIVE

The aim was to develop a means of predicting interface pressure from cuff inflation pressure during circumferential compression at the lower limb, in order to inform the design of soft exoskeletons.

BACKGROUND

Excessive mechanical loading of tissues can cause discomfort and soft tissue injury. Most ergonomic studies on exoskeletons are of interface pressure, but soft exoskeletons apply circumferential pressures similar to tourniquet cuffs by way of cuff inflation pressure. This study details the relationship between interface and cuff inflation pressures for pneumatic tourniquet cuffs.

METHOD

Pneumatic cuffs of different widths were inflated to target pressures on (A) a rigid cylinder, (B) the dominant thigh and calf, and (C) knee of healthy participants standing still. Interface pressures were measured under the cuffs using a pressure-sensing mat. Average interface pressures were then compared to cuff inflation pressures. The influence of cuff width, cuff inflation pressure, and participants' anthropometric data on pressure transmission was assessed.

RESULTS

A strong linear relationship between cuff inflation pressures and interface pressures was observed. Interface pressures were generally higher than cuff inflation pressures. The efficiency of pressure transmission to the lower limb depended on assessment site, adipose tissue thickness, cuff size, cuff inflation pressure, and possibly limb circumference. Regression equations were developed to predict interface pressures at the thigh, calf, and knee.

CONCLUSION

Interface pressures under pneumatic cuffs are influenced by the cuff size, cuff inflation pressure, and tissue compressibility. Predicted interface pressure from cuff inflation pressure and vice versa can be used to aid the design of soft exoskeletons.

Prehospital tourniquet use: An evaluation of community application and outcome

BACKGROUND

There is substantial investment in layperson and first responder training involving tourniquet use for hemorrhage control. Little is known however about prehospital tourniquet application, field conversion, or outcomes in the civilian setting. We describe the experience of a metropolitan region with prehospital tourniquet application.

METHODS

We conducted a retrospective cohort study characterizing prehospital tourniquet use treated by emergency medical services (EMS) in King County, Washington, from January 2018 to June 2019. Emergency medical services and hospital records were abstracted for demographics, injury mechanism, tourniquet details, clinical care, and outcomes. We evaluated the incidence of tourniquet application, who applied the device (EMS, law enforcement, or layperson), and subsequent course.

RESULTS

A total of 168 patients received tourniquet application, an incidence of 5.1 per 100,000 person-years and 3.48 per 1,000 EMS responses for trauma. Tourniquets were applied for penetrating trauma (64%), blunt trauma (30%), and bleeding ateriovenous fistulas (7%). A subset was critically ill: 13% had systolic blood pressures of <90 mm Hg, 8% had Glasgow Coma Scale score of <13, and 3% had cardiac arrest. Among initial applications, 48% were placed by law enforcement, 33% by laypersons, and 18% by EMS. Among tourniquets applied by layperson or law enforcement (n = 137), EMS relied solely on the original tourniquet in 45% (n = 61), placed a second tourniquet in 20% (n = 28), and removed the tourniquet without replacement in 35% (n = 48). Overall, 24% required massive transfusion, 59% underwent urgent surgery, and 21% required vascular surgery. Mortality was 3% (n = 4). At hospital discharge, the tourniquet limb was fully functional in 81%, partially functional in 10%, and nonfunctional in 9%; decreased function was not attributed to tourniquet application.

CONCLUSION

The high rate of application, need for urgent hospital intervention in a subset, and low incidence of apparent complication suggest that efforts to increase access and early tourniquet use can provide public health benefit.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Design and Development of a Hemorrhagic Trauma Simulator for Lower Limbs: A Pilot Study

One of the main preventable leading causes of death after a trauma injury is the hemorrhagic shock. Therefore, it is extremely important to learn how to control hemorrhages. In this paper, a hemorrhagic trauma simulator for lower limb has been developed and a pilot study has been accomplished to trail the simulator. Four different bleeding scenarios have been tested per participant, gathering information about the manual pressure exerted to control the bleeding. Data, altogether, from 54 hemorrhagic scenarios managed by final year medical students and doctors were gathered. Additionally, a post-simulation questionnaire, related to the usability of the simulator, was completed. All the participants managed to control the simulated bleeding scenarios, but the pressure exerted to control the four different scenarios is different depending if the trainee is a student or a doctor, especially in deep venous hemorrhages. This research has highlighted the different approach to bleeding control treatment between medical students and doctors. Moreover, this pilot study demonstrated the need to deliver a more effective trauma treatment teaching for hemorrhagic lesions and that hemorrhagic trauma simulators can be used to train and evaluate different scenarios.

CoQ10 augments candesartan protective effect against tourniquet-induced hind limb ischemia-reperfusion: Involvement of non-classical RAS and ROS pathways

Tourniquet is a well-established model of hind limb ischemia–reperfusion (HLI/R) in rats. Nevertheless, measures should be taken to alleviate the expected injury from ischemia/ reperfusion (I/R). In the present study, 30 adult male Sprague-Dawley rats were randomly divided into 5 groups (n = 6): control, HLI/R, HLI/R given candesartan (1 mg/kg, P.O); HLI/R given Coenzyme Q10 (CoQ10) (10 mg/kg, P.O); HLI/R given candesartan (0.5 mg/kg) and CoQ10 (5 mg/kg). The drugs were administered for 7 days starting one hour after reperfusion. Candesartan and CoQ10 as well as their combination suppressed gastrocnemius content of angiotensin II while they raised angiotensin-converting enzyme 2 (ACE2) activity, angiotensin (1–7) expression, and Mas receptor mRNA level. Consequently, candesartan and/or CoQ10 reversed the oxidative stress and inflammatory changes that occurred following HLI/R as demonstrated by the rise of SOD activity and the decline of MDA, TNF-α, and IL-6 skeletal muscle content. Additionally, candesartan and/or CoQ10 diminished gastrocnemius active caspase-3 level and phospho-p38 MAPK protein expression. Our study proved that CoQ10 enhanced the beneficial effect of candesartan in a model of tourniquet-induced HLI/R by affecting classical and non-classical renin-angiotensin system (RAS) pathway. To our knowledge, this is the first study showing the impact of CoQ10 on skeletal muscle RAS in rats.

Evaluation of the efficacy of commercial and noncommercial tourniquets for extremity hemorrhage control in a perfused cadaver model

BACKGROUND

Tourniquets are a critical tool in the immediate response to life-threatening extremity hemorrhage; however, the optimal tourniquet type and effectiveness of noncommercial devices remain unclear. Our aim was to evaluate the efficacy of five tourniquets in a perfused-cadaver model.

METHODS

This prospective study used a perfused-cadaver model with standardized superficial femoral artery injury bleeding at 700 mL/min. Five tourniquets were tested: combat application tourniquet; rapid application tourniquet system; Stretch, Wrap, And Tuck Tourniquet; an improvised triangle bandage windlass; and a leather belt. Forty-eight medical students underwent a practical hands-on demonstration of each tourniquet. Using a random number generator, they placed the tourniquets on the bleeding cadaver in random order. Time to hemostasis, time to secure devices, estimated blood loss, and difficulty rating were assessed. A one-way repeated measures analysis of variance was used to compare efficacy between the tourniquets in achieving the outcomes.

RESULTS

The mean ± SD participant age was 25 ± 2.6 years, and 29 (60%) were male. All but one tourniquet was able to stop bleeding, but the rapid application tourniquet system had a 4% failure rate. Time to hemostasis and estimated blood loss did not differ significantly (p > 0.05). Stretch, Wrap, And Tuck Tourniquet required the longest time to be secured (47.8 ± 17.0 seconds), whereas the belt was the fastest (15.2 ± 6.5 seconds; p < 0.001). The improvised windlass was rated easiest to learn and apply, with 22 participants (46%) assigning a score of 1.

CONCLUSION

Four of five tourniquets evaluated, including both noncommercial devices, effectively achieved hemostasis. A standard leather belt was the fastest to place and was able to stop the bleeding. However, it required continuous pressure to maintain hemostasis. The improvised windlass was as effective as the commercial devices and was the easiest to apply. In an emergency setting where commercial devices are not available, improvised tourniquets may be an effective bridge to definitive care.

Removal of the Prehospital Tourniquet in the Emergency Department

BACKGROUND

Life-threatening hemorrhage from extremity injuries can be effectively controlled in the prehospital environment through direct pressure, wound packing, and the use of tourniquets. Early tourniquet application has been prioritized for rapid control of severe extremity hemorrhage and is a cornerstone of prehospital trauma resuscitation guidelines. Emergency physicians must be knowledgeable regarding the initial assessment and appropriate management of patients who present with a prehospital tourniquet in place.

DISCUSSION

An interdisciplinary group of experts including emergency physicians, trauma surgeons, and tactical and Emergency Medical Services physicians collaborated to develop a stepwise approach to the assessment and removal (discontinuation) of an extremity tourniquet in the emergency department after being placed in the prehospital setting. We have developed a best-practices guideline to serve as a resource to aid the emergency physician in how to safely remove a tourniquet. The guideline contains five steps that include: 1) Determine how long the tourniquet has been in place; 2) Evaluate for contraindications to tourniquet removal; 3) Prepare for tourniquet removal; 4) Release the tourniquet; and 5) Monitor and reassess the patient.

CONCLUSION

These steps outlined will help emergency medicine clinicians appropriately evaluate and manage patients presenting with tourniquets in place. Tourniquet removal should be performed in a systematic manner with plans in place to immediately address complications.

Evaluating tourniquet use in Swedish prehospital care for civilian extremity trauma

Purpose

The use of tourniquet (TQ) is today a well-documented and lifesaving adjunct to control bleeding from extremity trauma in the military setting. Since August 2015, the ambulance services in Stockholm, Sweden are equipped with TQs. The implementation and potential complications related to TQ use have so far not been evaluated. The primary aim of this study was to evaluate the prehospital use of TQ for haemorrhage control in extremity trauma. Possible complications following the use of TQ were analysed.

Methods

A retrospective, descriptive cohort study of extremity haemorrhage for all patients (n = 56) with a documented prehospital use of TQ admitted to the trauma centre at Karolinska University Hospital from 1st August 2015 to 31st December 2017 was conducted. Data regarding TQ use including indication, duration, bleeding volume, complications and definitive injury were analysed.

Results

Out of 63 placements of TQ in 56 patients, TQ stopped the bleeding effectively in 98.2% of the cases and the TQ time varied from 15 to 100 min. The overall complication rate was 30.1%; however, complications possibly related to TQ use were 3.6%. In 16 (28.6%) cases, the TQ were used for a non-life-threating haemorrhage which may have been stopped with direct pressure only.

Conclusion

This study shows TQs to be an effective but overused tool in haemorrhage control. The use of TQ was not associated with any severe complications, implying the safety and effectiveness of the device in the civilian setting if TQ time is kept under 100 min.

Systematic review: Do commercial tourniquets have potential to be a life-saving intervention for ambulance services?

Background:

Globally, terrorist attacks have major impact because of high rates of mortality and severe injury. Compression with direct pressure may be time-consuming in limb exsanguination and accelerate onset of haemorrhagic shock. Tourniquet applications have undergone scrutiny over a long period, but recently tourniquets have been developed and modified for effective and efficient use in prehospital settings to mitigate adverse effects.

Objectives:

This systematic review aimed at examining commercial tourniquets that demonstrated efficacy for use in prehospital services.

Methods:

Six search engines (ScienceDirect, Ovid, PubMed, SAGE, SpringerLink, Taylor & Francis) were used and articles of which 14 were selected for data analysis.

Results:

The findings were not sufficiently conclusive to pinpoint whether one tourniquet application was superior overall; however, Combat Application Tourniquet appeared to be better than other commercial tourniquets in terms of occlusion of distal blood flow, easy and quick self-application and fewer complications.

Conclusion:

In prehospital settings, ambulance personnel should not hesitate to apply tourniquets when encountering critical circumstances in which they must choose between saving life and potential complications.

Prehospital Blood Product Transfusion in Mountain Rescue Operations

Severely injured patients with hemorrhage present major challenges for emergency medical services, especially during mountain rescue missions in which harsh environmental conditions and long out-of-hospital times are frequent. Because uncontrolled hemorrhage is the leading cause of death within the first 48 hours after severe trauma, initiating damage control resuscitation (DCR) as early as possible after severe trauma and exporting the concept of DCR to the out-of-hospital arena is pivotal for patient survival. Appropriate bleeding control, management of coagulopathy, and transfusion of blood products are core aspects of DCR. This review summarizes the available evidence on out-of-hospital blood product transfusion and the management of coagulopathy with a special focus on mountain rescue missions. An overview of upcoming trials and possible future trends in the management of coagulopathy during rescue operations is provided.

Bathroom Entrapment Leading to Cardiac Arrest From Crush Syndrome

Crush injuries have the potential to cause life-threatening systemic effects such as hyperkalemia, dysrhythmias, acute kidney injury, and renal failure. Systemic involvement is known as crush syndrome (CS) and results from tissue ischemia and muscle necrosis. This is a report of a 76-year-old female who developed a fatal dysrhythmia following release of her extremity from prolonged entrapment in bathroom safety equipment. Hyperkalemia should be presumed in any crush injury and be treated empirically and aggressively. Although tourniquet application prior to extrication is not widely recommended to prevent CS, it should be considered in prolonged extremity entrapment.

Bleeding Control With Limb Tourniquet Use in the Wilderness Setting: Review of Science

The purpose of this review is to summarize tourniquet science for possible translation to wilderness settings. Much combat casualty data has been studied since 2005, and use of tourniquets in the military has changed from a last resort to first aid. The US Government has made use of tourniquets a health policy aimed to improve public access to bleeding control items. International authorities believe that education in first aid should be universal, as all can and should learn first aid. The safety record of tourniquet use is mixed, but users are reliably safe if trained well. Well-designed tourniquets can reliably attain bleeding control, may mitigate risk of shock progression, and may improve survival rates, but conclusive proof of a survival benefit remains unclear in civilian settings. Even a war setting has a bias toward survivorship by sampling mostly survivors in hospitals. Improvised tourniquets are less reliable than well-designed tourniquets but may be better than none. The tourniquet model used most often in 2016 by the US military is the Combat Application Tourniquet (C-A-T), and civilians use an array of various models, including C-A-T. Evidence on tourniquet use to date indicates that most uses are safe and effective in civilian settings. Future directions for study relevant to the wilderness setting include consideration of research priorities, study of the burdens of injury or capability gaps in caregiving for various wilderness settings, determination of the skill needs of outdoor enthusiasts and wilderness caregivers, and survey of wilderness medicine stewards regarding bleeding control.

The trauma center is too late: Major limb trauma without a pre-hospital tourniquet has increased death from hemorrhagic shock

BACKGROUND

To date, no civilian studies have demonstrated that pre-hospital (PH) tourniquets improve survival. We hypothesized that late, trauma center (TC) tourniquet use would increase death from hemorrhagic shock compared to early (PH) placement.

METHODS

All patients arriving to a Level 1, urban TC between October 2008 and January 2016 with a tourniquet placed before (T-PH) or after arrival to the TC (T-TC) were evaluated. Cases were assigned the following designations: indicated (absolute indication [vascular injury requiring repair/ligation, operation within 2 hours for extremity injury, or traumatic amputation] or relative indication [major musculoskeletal/soft tissue injury requiring operation 2-8 hours after arrival, documented large blood loss]) or non-indicated. Outcomes were death from hemorrhagic shock, physiology upon arrival to the TC, and massive transfusion requirements. After univariate analysis, logistic regression was carried out to assess independent predictors of death from hemorrhagic shock.

RESULTS

A total of 306 patients received 326 tourniquets for injuries to 157 upper and 147 lower extremities. Two hundred eighty-one (92%) had an indication for placement. Seventy percent of patients had a blunt mechanism of injury. T-TC patients arrived with a lower systolic blood pressure (SBP, 101 [86, 123] vs. 125 [100, 145] mm Hg, p < 0.001), received more transfusions in the first hour of arrival (55% vs. 34%, p = 0.02), and had a greater mortality from hemorrhagic shock (14% vs. 3.0%, p = 0.01). When controlling for year of admission, mechanism of injury and shock upon arrival (SBP ≤90 mm Hg or HR ≥120 bpm or base deficit ≤ 4) indicated T-TC had a 4.5-fold increased odds of death compared to T-PH (OR 4.5, 95% CI 1.23-16.4, p = 0.02).

CONCLUSIONS

Waiting until TC arrival to control hemorrhage with a tourniquet was associated with worsened blood pressure and increased transfusion within the first hour of arrival. In routine civilian trauma patients, delaying to T-TC was associated with 4.5-fold increased odds of mortality from hemorrhagic shock.

LEVEL OF EVIDENCE

Level IV.

Morphological Regeneration and Functional Recovery of Neuromuscular Junctions after Tourniquet-Induced Injuries in Mouse Hindlimb

Tourniquet application and its subsequent release cause serious injuries to the skeletal muscle, nerve, and neuromuscular junction (NMJ) due to mechanical compression and ischemia-reperfusion (IR). Monitoring structural and functional repair of the NMJ, nerve, and skeletal muscle after tourniquet-induced injuries is beneficial in exploring potential cellular and molecular mechanisms responsible for tourniquet-induced injuries, and for establishing effective therapeutic interventions. Here, we observed long-term morphological and functional changes of the NMJ in a murine model of tourniquet-induced hindlimb injuries. Unilateral hindlimbs of C57/BL6 mice were subjected to 3 h of tourniquet by placing an orthodontic rubber band, followed by varied periods of tourniquet release (1 day, 3 days, 1 week, 2 weeks, 4 weeks, and 6 weeks). NMJ morphology in the gastrocnemius muscle was imaged, and the endplate potential (EPP) was recorded to evaluate NMJ function. In NMJs, nicotinic acetylcholine receptor (nAChR) clusters normally displayed an intact, pretzel-like shape, and all nAChR clusters were innervated (100%) by motor nerve terminals. During 3 h of tourniquet application and varied periods of tourniquet release, NMJs in the gastrocnemius muscle were characterized by morphological and functional changes. At 1 day and 3 days of tourniquet release, nAChR clusters retained normal, pretzel-like shapes, whereas motor nerve terminals were completely destroyed and no EPPs recorded. From 1 to 6 weeks of tourniquet release, motor nerve terminals gradually regenerated, even reaching that seen in sham mice, whereas nAChR clusters were gradually fragmented with prolongation of tourniquet release. Additionally, the amplitude of EPPs gradually increased with prolongation of tourniquet release. However, even at 6 weeks after tourniquet release, the amplitude of EPPs did not restore to the level seen in sham mice (13.9 ± 1.1 mV, p < 0.05 vs. sham mice, 29.8 ± 1.0 mV). The data suggest that tourniquet application and subsequent release impair the structure and function of NMJs. Morphological change in motor nerve terminals is faster than in nAChR clusters in NMJs. Slow restoration of fragmented nAChR clusters possibly dampens neuromuscular transmission during the long phase following tourniquet release.

Dexamethasone promotes long-term functional recovery of neuromuscular junction in a murine model of tourniquet-induced ischaemia-reperfusion

AIM

Tourniquet-induced ischaemia and subsequent reperfusion cause serious ischaemia-reperfusion (IR) injury in the neuromuscular junction (NMJ) and skeletal muscle. Here, we investigated whether dexamethasone (Dex) promotes long-term functional recovery of the NMJ and skeletal muscle in tourniquet-induced hindlimb IR.

METHODS

Unilateral hindlimb of C57/BL6 mice was subjected to 3 h of ischaemia following 6 weeks of reperfusion (6-wk IR). Dex treatment began on the day of IR induction and lasted for different periods. Sciatic nerve-stimulated gastrocnemius muscle contraction was detected in situ. Function of the NMJ was measured in situ using electrophysiological recording of the miniature endplate potential (mEPP) and endplate potential (EPP). Western blot was used to detect protein expression of nicotinic acetylcholine receptors (nAChRs) in gastrocnemius muscles.

RESULTS

Gastrocnemius muscle contraction in mice with 6-wk IR was about 60% of normal skeletal muscle contraction recorded in age-matched sham mice. The amplitude of the mEPP and EPP was lower in mice with 6-wk IR, compared to sham mice. Dex treatment for 1 or 3 days did not restore the function of the NMJ and improve gastrocnemius muscle contraction in mice with 6-wk IR. Dex treatment for 1 week exerted a maximum effect on improving the function of the NMJ and skeletal muscle, with the effect of Dex gradually lessening with prolonged Dex treatment. There are no significant differences in protein expression of nAChR-α1 and nAChR-β1 subunits in the gastrocnemius muscle among all groups.

CONCLUSION

Dex promotes repair of the NMJ and subsequently restores skeletal muscle contractile function in tourniquet-induced 6-wk IR.

Safety and Appropriateness of Tourniquets in 105 Civilians

BACKGROUND

The United States military considers tourniquets to be effective for controlling bleeding from major limb trauma. The purpose of this study was to assess whether tourniquets are safely applied to the appropriate civilian patient with major limb trauma of any etiology.

METHODS

Following IRB approval, patients arriving to a level-1 trauma center between October 2008 and May 2013 with a prehospital (PH) or emergency department (ED) tourniquet were reviewed. Cases were assigned the following designations: absolute indication (operation within 2 hours for limb injury, vascular injury requiring repair/ligation, or traumatic amputation); relative indication (major musculoskeletal/soft-tissue injury requiring operation 2-8 hours after arrival, documented large blood loss); and non-indicated. Patients with absolute or relative indications for tourniquet placement were defined as indicated, while the remaining were designated as non-indicated. Complications potentially associated with tourniquets, including amputation, acute renal failure, compartment syndrome, nerve palsies, and venous thromboembolic events, were adjudicated by orthopedic, hand or trauma surgical staff. Univariate analysis was performed to compare patients with indicated versus non-indicated tourniquet placement.

RESULTS

A total of 105 patients received a tourniquet for injuries sustained via sharp objects, i.e., glass or knives (32%), motor vehicle collisions (30%), or other mechanisms (38%). A total of 94 patients (90%) had indicated tourniquet placement; 41 (44%) of which had a vascular injury. Demographics, mechanism, transport, and vitals were similar between patients that had indicated or non-indicated tourniquet placement. 48% of the indicated tourniquets placed PH were removed in the ED, compared to 100% of the non-indicated tourniquets (p < 0.01). The amputation rate was 32% among patients with indicated tourniquet placement (vs. 0%; p = 0.03). Acute renal failure (3.2 vs. 0%, p = 0.72), compartment syndrome (2.1 vs. 0%, p = 0.80), nerve palsies (5.3 vs. 0%; p = 0.57), and venous thromboembolic events (9.1 vs. 8.5%; p = 0.65) and were similar in patients that had indicated compared to non-indicated tourniquet placement. After adjudication, no complication was a result of tourniquet use.

CONCLUSION

The current study suggests that PH and ED tourniquets are used safely and appropriately in civilians with major limb trauma that occur via blunt and penetrating mechanisms.

Trends and Predictors of Limb Tourniquet Use by Civilian Emergency Medical Services in the United States

BACKGROUND

Tourniquet use by Emergency Medical Services (EMS) can be life saving for severely injured patients. The adoption of this intervention is not well described in civilian settings. This study describes patterns and trends of tourniquet use by civilian EMS and identifies predictors of such use.

METHODS

A retrospective study of four consecutive releases of the U.S. National Emergency Medical Services Information System (NEMSIS) public research dataset (2011-14) was conducted. Descriptive analysis was performed to compare two groups of EMS activations for injuries with or without tourniquet application. This was followed by multivariate logistic regression to identify predictors of tourniquet use.

RESULTS

A total of 2,048 tourniquet applications were documented among all EMS activations for injured patients (N = 10,366,537) yielding a prevalence of 0.2 per 1,000 EMS activations. Tourniquets were mainly applied in young (mean age 44.0 ± 21.1 years) male patients (76.5%) in urban and suburban EMS activations (86.4%) and by advanced life support (ALS) EMS services (81.6%). Most common complaints reported by dispatch for EMS activations with tourniquet use were Traumatic injury (25.3%), Hemorrhage/laceration (23.5%), and Traffic accident (16.8%) with injuries mainly related to Stabbing/Accidental cutting (20.3%), Falls (17.1%), and Motor vehicle traffic accident (11.5%). Upper extremity injuries (39.6%) were more common than Lower extremity injuries (27.3%). The providers' primary impression was predominantly Traumatic injury (92.8%), and patients' primary symptoms were mainly Bleeding (50.4%) and Wound (28.7%). All prehospital time intervals except on-scene time interval were significantly shorter in the group with tourniquets compared to the group without tourniquets (p < 0.05). Reported prevalence of tourniquet use by EMS (per 1,000 EMS injury activations) increased from 2011 to 2012 then stabilized over the following years (2012-14). Significant predictors of tourniquet use reported by the provider were identified and included demographic characteristics, EMS agency type, specific complaints, injury cause, injury anatomic location, chief complaint organ system, and primary symptom.

CONCLUSION

Reported tourniquet use by EMS for injured patients in the U.S. is low. Increasing adoption mainly by urban services was noted. Predictors for tourniquet use in civilian trauma were identified. Establishing the effectiveness of this intervention by comparing patient outcomes is needed. Key words: emergency medical services; prehospital; tourniquet; injury; NEMSIS; hemorrhage.

A hybrid simulator model for the control of catastrophic external junctional haemorrhage in the military environment

Catastrophic haemorrhage from extremity injuries has for a long time been the single most common cause of preventable death in the military environment. The effective use of extremity tourniquets has increased the survival of combat casualties, and exsanguination from isolated limb injuries is no longer the most common cause of death. Today, the most common cause of potentially preventable death is haemorrhage from the junctional zones, i.e. the most proximal part of the extremities, not amenable to standard tourniquets.

Different training techniques to control catastrophic haemorrhage have been used by the Swedish Armed Forces in the pre-deployment training of physicians, nurses and medics for many years. The training techniques include different types of human patient simulators such as moulage patients and manikins. Preferred training conditions for the control of catastrophic haemorrhage include a high degree of realism, in combination with multiple training attempts.

This report presents a new hybrid training model for catastrophic external junctional haemorrhage control. It offers a readily reproducible, simple and inexpensive opportunity to train personnel to deal with life threatening catastrophic junctional haemorrhage. In particular, this model offers an opportunity for non-medical military personnel in Sweden to practice control of realistic catastrophic haemorrhage, with multiple training attempts.

Military-to-civilian translation of battlefield innovations in operative trauma care

BACKGROUND

Historic improvements in operative trauma care have been driven by war. It is unknown whether recent battlefield innovations stemming from conflicts in Iraq/Afghanistan will follow a similar trend. The objective of this study was to survey trauma medical directors (TMDs) at level 1-3 trauma centers across the United States and gauge the extent to which battlefield innovations have shaped civilian practice in 4 key domains of trauma care.

METHODS

Domains were determined by the use of a modified Delphi method based on multiple consultations with an expert physician/surgeon panel: (1) damage control resuscitation (DCR), (2) tourniquet use, (3) use of hemostatic agents, and (4) prehospital interventions, including intraosseous catheter access and needle thoracostomy. A corresponding 47-item electronic anonymous survey was developed/pilot tested before dissemination to all identifiable TMD at level 1-3 trauma centers across the US.

RESULTS

A total of 245 TMDs, representing nearly 40% of trauma centers in the United States, completed and returned the survey. More than half (n = 127; 51.8%) were verified by the American College of Surgeons. TMDs reported high civilian use of DCR: 95.1% of trauma centers had implemented massive transfusion protocols and the majority (67.7%) tended toward 1:1:1 packed red blood cell/fresh-frozen plasma/platelets ratios. For the other 3, mixed adoption corresponded to expressed concerns regarding the extent of concomitant civilian research to support military research and experience. In centers in which policies reflecting battlefield innovations were in use, previous military experience frequently was acknowledged.

CONCLUSION

This national survey of TMDs suggests that military data supporting DCR has altered civilian practice. Perceived relevance in other domains was less clear. Civilian academic efforts are needed to further research and enhance understandings that foster improved trauma surgeon awareness of military-to-civilian translation.

Emergency department evaluation and treatment of acute hip and thigh pain

Although the incidence of hip fractures is decreasing, the overall prevalence continues to increase because of an aging population. People older than 65 suffer fractures at a rate of 0.6% per year--2% per year for persons older than 85. One in 5 patients suffering a hip fracture will die within a year. Additionally, the emergency physician must consider entities such as avascular necrosis, compartment syndrome, and muscular disruption. This article reviews patterns and complications of acute hip and thigh injuries and clinically relevant diagnostic, anesthetic, and treatment options that facilitate timely, appropriate, and effective emergency department management.

Application of current hemorrhage control techniques for backcountry care: part one, tourniquets and hemorrhage control adjuncts

Decade-long advancements in battlefield medicine have revolutionized the treatment of traumatic hemorrhage and have led to a significant reduction in mortality. Older methods such as limb elevation and pressure points are no longer recommended. Tourniquets have had a profound effect on lives saved without the commonly feared safety issues that have made them controversial. Unique tourniquet designs for inguinal and abdominal regions are now available for areas not amenable to current fielded extremity tourniquets. This article, the first of two parts, reviews the literature for advancements in prehospital hemorrhage control for any provider in the austere setting. It emphasizes the significant evidence-based advances in tourniquet use on the extremities that have occurred in battlefield trauma medicine since 2001 and reviews the newer junctional tourniquet devices. Recommendations are made for equipment and techniques for controlling hemorrhage in the wilderness setting.

Prevention of tissue hypoperfusion in the trauma patient: initial management

This article outlines the challenges of identification and management of tissue hypoperfusion as a consequence of haemorrhagic shock in civilian polytrauma cases. It also describes damage resuscitation, but does not cover specific trauma cases such as pregnancy, burns, head injuries, children and elderly trauma.

Tourniquet use for peripheral vascular injuries in the civilian setting

BACKGROUND

Haemorrhage in peripheral vascular injuries may cause life-threatening exsanguination. Tourniquets are used extensively by the military, with increased interest in the civilian setting to prevent deaths. This is a retrospective study of trauma patients at two large Canadian trauma centres with arterial injury after isolated extremity trauma. We hypothesized that tourniquet use may decrease mortality rate and transfusion requirements if applied early.

METHODS

The study group was all adult patients at two Level 1 Trauma Centres in two Canadian cities in Canada, who had arterial injuries from extremity trauma. The study period was from January 2001 to December 2010. We excluded patients with significant associated injuries. The intervention in this study was prehospital tourniquet use. The main outcome was in-hospital mortality. Secondary outcomes were length of stay, compartment syndrome, amputation, and blood product transfusion.

RESULTS

190 patients were included in the study, and only 4 patients had a prehospital tourniquet applied. They arrived directly from the scene of injury, had improvised tourniquets by police or bystanders, and showed a trend to be more hypotensive and acidotic. Four other patients had tourniquets applied in the trauma bay within 1h of injury. There were no differences in age, sex, injury severity or physiologic presentation between patients who had an early tourniquet applied and those who died without a tourniquet. However, six patients died without a tourniquet, and all bled to death. Of the eight patients who had early tourniquets applied, none died.

CONCLUSIONS

Tourniquets may prevent exsanguination in the civilian setting for patients suffering either blunt or penetrating trauma to the extremity. Future studies will help determine the utility of deploying tourniquets in the civilian setting, given the rarity of exsanguinating haemorrhage from isolated extremity trauma in this setting.

Auto-transfusion tourniquets: the next evolution of tourniquets

In this article, we discuss the relationship between hemorrhagic shock and the pathophysiology of shock using conventional tourniquets. We will focus on corollary benefits with the use of HemaClear(®), a self-contained, sterile, exsanguinating auto-transfusion tourniquet. This discussion will demonstrate that the use of auto-transfusion tourniquets is a practical evidence-based approach in fluid resuscitation: it shortens the duration of shock after hemorrhage and trauma compared with conventional tourniquets. Emphasis is placed on the use of the HemaClear(®) as an alternative fluid resuscitation tool which is more efficient in the battlefield, pre-hospital and in-hospital settings.

Identifying future 'unexpected' survivors: a retrospective cohort study of fatal injury patterns in victims of improvised explosive devices

OBJECTIVES

To identify potentially fatal injury patterns in explosive blast fatalities in order to focus research and mitigation strategies, to further improve survival rates from blast trauma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

UK military personnel killed by improvised explosive device (IED) blasts in Afghanistan, November 2007-August 2010.

SETTING

UK military deployment, through NATO, in support of the International Security Assistance Force (ISAF) mission in Afghanistan.

DATA SOURCES

UK military postmortem CT records, UK Joint Theatre Trauma Registry and associated incident data.

MAIN OUTCOME MEASURES

Potentially fatal injuries attributable to IEDs.

RESULTS

We identified 121 cases, 42 mounted (in-vehicle) and 79 dismounted (on foot), at a point of wounding. There were 354 potentially fatal injuries in total. Leading causes of death were traumatic brain injury (50%, 62/124 fatal injuries), followed by intracavity haemorrhage (20.2%, 25/124) in the mounted group, and extremity haemorrhage (42.6%, 98/230 fatal injuries), junctional haemorrhage (22.2%, 51/230 fatal injuries) and traumatic brain injury (18.7%, 43/230 fatal injuries) in the dismounted group.

CONCLUSIONS

Head trauma severity in both mounted and dismounted IED fatalities indicated prevention and mitigation as the most effective strategies to decrease resultant mortality. Two-thirds of dismounted fatalities had haemorrhage implicated as a cause of death that may have been anatomically amenable to prehospital intervention. One-fifth of the mounted fatalities had haemorrhagic trauma which currently could only be addressed surgically. Maintaining the drive to improve all haemostatic techniques for blast casualties, from point of wounding to definitive surgical proximal vascular control, alongside the development and application of novel haemostatic interventions could yield a significant survival benefit. Prospective studies in this field are indicated.