Extending existing recommended military casualty evacuation timelines will likely increase morbidity and mortality: a UK consensus statement

INTRODUCTION

Future conflicts may have limited use of aviation-based prehospital emergency care for evacuation. This will increase the likelihood of extended evacuation timelines and an extended hold at a forward hospital care facility following the completion of damage control surgery or acute medical interventions.

METHODS

A three-round Delphi Study was undertaken using a panel comprising 44 experts from the UK armed forces including clinicians, logisticians, medical planners and commanders. The panel was asked to consider the effect of an extended hold at Deployed Hospital Care (Forward) from the current 2-hour timeline to +4, +8, +12 and +24 hours on a broad range of clinical and logistical issues. Where 75% of respondents had the same opinion, consensus was accepted. Areas where consensus could not be achieved were used to identify future research priorities.

RESULTS

Consensus was reached that increasing timelines would increase the personnel, logistics and equipment support required to provide clinical care. There is a tipping point with a prolonged hold over 8 hours, after which the greatest number of clinical concerns emerge. Additional specialties of surgeons other than general and orthopaedic surgeons will likely be required with holds over 24 hours, and robust telemedicine would not negate this requirement.

CONCLUSIONS

Retaining acute medical emergencies at 4 hours, and head injuries was considered a particular risk. This could potentially be mitigated by an increased forward capacity of some elements of medical care and availability of a CT scanner and intracranial pressure monitoring at over 12 hours. Any efforts to mitigate the effects of prolonged timelines will come at the expense of an increased logistical burden and a reduction in mobility. Ultimately the true effect of prolonged timelines can only be answered by close audit and analysis of clinical outcomes during future operations with an extended hold.

Minimum depths to essential structures in a UK military population using computed tomography: application to stab-resistant body armour

INTRODUCTION

Edged weapons are a known domestic threat to the police forces of the UK. This threat is mitigated by wearing stab-resistant body armour that is either worn overtly or covertly depending on role. Although the UK military have traditionally focused their body armour design upon ballistic and fragmentation threats, future roles may require protection against an edged weapon threat. Since 2017, UK police body armour requirements for anatomical coverage for both edged weapon and ballistic threats are now based upon the requirements of UK military. This revised coverage may need additional research to determine minimum distances to essential structures.

METHOD

Three entry locations and penetration vectors were chosen using the limited available information in the literature, in combination with a specialist in edged weapons defence. One hundred twenty CT trauma scans of male military service personnel were subsequently analysed to ascertain minimum distances from skin surface to the first structure encountered that is included in essential coverage (heart, aorta, vena cava, liver and spleen) at 3 specific entry points.

RESULTS

Individuals ranged between 18 and 46 years, with a mean body mass index of 24.8. The absolute minimum depth from skin surface to a structure within the auspice of essential coverage was 17 mm to the liver in entry point 3 and 19 mm to the heart in entry point 2.

CONCLUSIONS

Minimum distances to critical structures were significantly larger than those described in previous studies on civilians. This study will be used to supplement existing evidence to support existing UK police requirements for stab-resistant body armour. Using the weapon entry sites and vectors described in this study, overmatching to a behind armour depth of 17 mm would cover all of this population in this study.

UK military helmet design and test methods

The aim of this paper was to provide the military medical community with an expert summary of military helmets used by HM Armed Forces. The design of military helmets and test methods used to determine the fragmentation and non-ballistic impact protection are discussed. The helmets considered are Parachutist, Combat Vehicle Crewman, Mk6, Mk6A, Mk7 and VIRTUS. The helmets considered provide different levels of fragmentation and non-ballistic impact protection dictated by the materials available at the time of the helmet design and the end-user requirement. The UK Ministry of Defence defines the area of coverage of military helmets by considering external anatomical features to provide protection to the brain and the majority of the brainstem. Established test methods exist to assess the performance of the helmet with respect to the threats; however, these test methods do not typically consider anatomical vulnerability.

Edged weapons awareness

Edged weapons (sometimes referred to as sharp weapons or blades) are an increasing threat to military personnel, the blue light community (police, ambulance, firefighters, other first responders) and the general public worldwide. The use of edged weapons in criminal and terrorist incidents internationally means the forensic community needs an awareness of the technology of edged weapons, how they are used, the damage (clothing and wounding) that might be caused and any other forensic implications. In this paper, the magnitude of the problem is presented, prior research summarised and implications for forensic investigations discussed.

AAGBI: Safer pre-hospital anaesthesia 2017: Association of Anaesthetists of Great Britain and Ireland

Pre-hospital emergency anaesthesia with oral tracheal intubation is the technique of choice for trauma patients who cannot maintain their airway or achieve adequate ventilation. It should be carried out as soon as safely possible, and performed to the same standards as in-hospital emergency anaesthesia. It should only be conducted within organisations with comprehensive clinical governance arrangements. Techniques should be straightforward, reproducible, as simple as possible and supported by the use of checklists. Monitoring and equipment should meet in-hospital anaesthesia standards. Practitioners need to be competent in the provision of in-hospital emergency anaesthesia and have supervised pre-hospital experience before carrying out pre-hospital emergency anaesthesia. Training programmes allowing the safe delivery of pre-hospital emergency anaesthesia by non-physicians do not currently exist in the UK. Where pre-hospital emergency anaesthesia skills are not available, oxygenation and ventilation should be maintained with the use of second-generation supraglottic airways in patients without airway reflexes, or basic airway manoeuvres and basic airway adjuncts in patients with intact airway reflexes.

Laboratory evaluation of a novel anaesthesia delivery device

Here, we describe proof of concept of a novel method for delivering volatile anaesthetics, where the liquid anaesthetic (sevoflurane or isoflurane) is formulated into an emulsion that is contained in a compact, lightweight device through which carrier gas flows. Release of anaesthetic is achieved by stirring of the formulation, allowing controlled and responsive release of anaesthetic at a variety of fixed flow rates between 0.5 l.min^-1 and 5 l.min^-1 , with ventilated, non-ventilated and draw-over breathing systems. Anaesthetic release was evaluated using target anaesthetic concentrations ranging from 0.5% v/v to 8% v/v to mimic those typically required for induction and maintenance of anaesthesia, and lower concentrations suitable for sedation. Under all conditions, output could be maintained within 0.1% v/v of the intended setting, and the device could deliver a controlled level of anaesthetic for at least 60 min, with compensation for different ambient temperatures (10-30 °C) and carrier gas flow rates. This device offers a simple, inexpensive method of delivering safe concentrations of volatile anaesthetics for a wide range of applications.

Died of wounds: a mortality review

OBJECTIVES

Combat casualty care is a complex system involving multiple clinicians, medical interventions and casualty transfers. Improving the performance of this system requires examination of potential weaknesses. This study reviewed the cause and timing of death of casualties deemed to have died from their injuries after arriving at a medical treatment facility during the recent conflicts in Iraq and Afghanistan, in order to identify potential areas for improving outcomes.

METHODS

This was a retrospective review of all casualties who reached medical treatment facilities alive, but subsequently died from injuries sustained during combat operations in Afghanistan and Iraq. It included all deaths from start to completion of combat operations. The UK military joint theatre trauma registry was used to identify cases, and further data were collected from clinical notes, postmortem records and coroner's reports.

RESULTS

There were 71 combat-related fatalities who survived to a medical treatment facility; 17 (24%) in Iraq and 54 (76%) in Afghanistan. Thirty eight (54%) died within the first 24 h. Thirty-three (47%) casualties died from isolated head injuries, a further 13 (18%) had unsurvivable head injuries but not in isolation. Haemorrhage following severe lower limb trauma, often in conjunction with abdominal and pelvic injuries, was the cause of a further 15 (21%) deaths.

CONCLUSIONS

Severe head injury was the most common cause of death. Irrespective of available medical treatment, none of this group had salvageable injuries. Future emphasis should be placed in preventative strategies to protect the head against battlefield trauma.

Modelling the blast environment and relating this to clinical injury: experience from the 7/7 inquest

This paper addresses the computational modelling of a series of specific blast-related incidents and the relationships of clinical and engineering interpretations. The Royal Centre for Defence Medicine and the Defence Science and Technology Laboratory were tasked in 2010 by the UK Ministry of Defence to assist the Coroner's inquests into the 7 July 2005 London bombings. A three phase approach was taken. The first phase included an engineering expert in blast effects on structures reviewing photographs of the damaged carriages and bus to give a view on the likely physical effects on people close to the explosions. The second phase was a clinical review of the evidence by military clinicians to assess blast injury in the casualties. The third phase was to model the blast environment by structural dynamics experts to assess likely blast loading on victims to evaluate the potential blast loading on individuals. This loading information was then assessed by physiology experts. Once all teams (engineering, clinical and modelling/physiological) had separately arrived at their conclusions, the information streams were integrated to arrive at a consensus. The aim of this paper is to describe the methodology used as a potential model for others to consider if faced with a similar investigation, and to show the benefit of the transition of military knowledge to a civilian environment.

Primary blast lung injury at a NATO Role 3 hospital

BACKGROUND

Primary blast lung injury (PBLI) is defined as lung contusion from barotrauma following an explosive mechanism of injury (MOI). Military data have focused on PBLI characteristics following evacuation from the combat theatre; less is known about its immediate management and epidemiology in the deployed setting. We conducted a quality improvement project to describe the prevalence, clinical characteristics, management strategies and evacuation techniques for PBLI patients prior to evacuation.

METHODS

Patients admitted to a Role 3 hospital in southwest, Afghanistan, from January 2008 to March 2013 with a blast MOI were identified through the Department of Defense Trauma Registry; International Classification of Diseases 9 codes and patient record review were used to identify the PBLI cohort from radiology reports. Descriptive statistics and Fishers exact test were used to report findings.

RESULTS

Prevalence of PBLI among blast injured patients with radiology reports was 11.2% (73/648). The population exhibited high Injury Severity Scores median 25 (IQR 14-34) and most received a massive blood transfusion (mean 33.4±38.3 total blood products/24 h). The mean positive end expiratory pressure (PEEP) requirement was 6.2±3.7 (range 5-15) cm H2O and PaO2 to FiO2 ratio was 297±175.2 (66-796) mm Hg. However, 16.6% of patients had a PaO2 to FiO2 ratio <200, 13.3% required PEEP ≥10 cm H2O and one patient required specialised evacuation for respiratory failure. A dismounted MOI (72.8%) and evacuation from point of injury by the Medical Emergency Response Team (62.3%) appeared to be associated with worse lung injury. Only eight of the 73 PBLI patients died and of the five with retrievable records, none died from respiratory failure.

CONCLUSIONS

PBLI has a low prevalence and conventional lung protective ventilator management is generally appropriate immediately after injury; application of advanced modes of ventilation and specialised evacuation assistance may be required. PBLI may be a marker of underlying injury severity since all deaths were not due to respiratory failure. Further work is needed to determine exact MOI in mounted and dismounted casualties.

Haemorrhage and coagulopathy in the Defence Medical Services

Over the past 12 years, the United Kingdom Defence Medical Services have evolved an integrated 'damage control resuscitation - damage control surgery' sequence for the management of patients sustaining complex injuries. During 2009, over 3200 units of blood products were administered as massive transfusions to severely injured UK personnel. An important part of the approach to traumatic bleeding is the early, empirical use of predefined ratios of blood and clotting products. As soon as control of bleeding is achieved, current practice is to switch towards a tailored transfusion, based on clinical and laboratory assessments, including point-of-care coagulation testing. A key goal is to provide resuscitation seamlessly throughout surgery, so that patients leave the operating room with their normal physiology restored. This article outlines the current management of haemorrhage and coagulation employed in Afghanistan from the point of wounding to transfer back to the National Health Service.

The clinical outcome of UK military personnel who received a massive transfusion in Afghanistan during 2009

OBJECTIVES

The UK Defence Medical Services has developed a Massive Transfusion Protocol (MTP) that forms part of the initial Damage Control Resuscitation process for severely injured combat casualties. The key objectives of this retrospective review of MTP recipients are to document the survival rates, level of critical care support required and the blood components transfused as part of the Massive Transfusion Protocol in Afghanistan during 2009. In addition to providing a measure of our current effectiveness it should also provide a reference point for future reviews as the MTP continues to evolve.

METHODS

This was a collaborative project involving the Royal Centre for Defence Medicine and the Critical Care Department, University Hospitals Birmingham. It was limited to UK military personnel who were injured in 2009 and received massive transfusions (defined as the transfusion of 10 or more units of packed red blood cells over a 24-hour period) at Camp Bastion Role 3 Medical Facility, Afghanistan.

RESULTS

During the 12-month period, 59 personnel received massive transfusions. 51 (86%) personnel survived to be discharged from hospital in the UK. 48 (92%) personnel required ventilatory support for a median of 3 (2-8) days. The longest period of ventilation was 40 days; 29 (55%) personnel required vasopressor support and eight personnel (15%) required renal replacement therapy. The median total transfusion of blood components was 45 (28.5-62) units. There were seven transfusions of more than 100 units. Five of the personnel in this group (including the recipient of a 237-unit transfusion) survived to be discharged from University Hospitals Birmingham. On average, 1.21 (SD 0.28) units of packed red blood cells were transfused for every unit of fresh frozen plasma.

CONCLUSIONS

The use of the current MTP was associated with a high rate of survival. Survivors require a continuity of critical care with a median demand for 3 days. The early use of plasma and platelets can be successfully delivered in the battlefield despite operational and logistic constraints.

Is pre-hospital thoracotomy necessary in the military environment?

INTRODUCTION

Exsanguination from penetrating torso injury is a major source of mortality on the battlefield. Advanced Life Support guidelines suggest 'on-scene' thoracotomy for patients in cardiac arrest following penetrating chest trauma. This requires significant resourcing and training. Experience from published series (31 pre-hospital thoracotomies with 3 survivors) suggests that when this manoeuvre is applied to a well selected group it is a significant and life-saving procedure. Can this be applied to military injuries?

METHODS

Over a 12 month period on Operation Herrick all patients who sustained significant thoracic trauma were retrospectively reviewed. Parameters were recorded to allow detailed analysis of injury pattern and operative management. Our main objective was to determine if an early (pre-hospital) thoracotomy would have influenced the outcome.

RESULTS

Over the period, 81 patients required operative intervention following thoracic trauma: 8 patients underwent emergency thoracotomy (performed as part of the resuscitation) and 14 underwent urgent thoracotomy (performed after physiology partly restored). There were 9 fatalities--7 undergoing emergency thoracotomy and 2 post-operatively from multi-organ failure. Of the 7 intra-operative deaths 4/7 patients had thoracic injury and 6/7 had additional abdominal injuries. The median predicted survival of fatalities was 2.0% using Trauma Injury Severity Scoring.

DISCUSSION

Emergency thoracotomy should be performed in cardiac arrest following penetrating trauma as soon as possible. Highest survival rates in both in-hospital and pre-hospital thoracotomy are found in isolated cardiac stab wounds (19.4%). Poorest survival is found in multiply, ballistic injured patients (0.7%). The latter best reflects the injury pattern of military patients who have cardiac arrest following penetrating torso injury.

CONCLUSION

As our injury pattern suggests, any pre-hospital thoracotomy on military patients is likely to require complex intervention in very challenging environments. Our evidence does not support the notion that earlier thoracotomy could improve survival.

The Joint Theatre Clinical Case Conference (JTCCC): clinical governance in action

OBJECTIVES

To quantify the type and nature of the lessons and issues arising from the Joint Theatre Clinical Case Conference

METHODS

An evaluation of all JTCCC minutes from inception on 30 Mar 07 to 05 Jun 08 (n = 61) was performed in Jul 08. Each separate issue (n = 207) was assigned a NATO 'J' category and further sub-divided into clinical and non-clinical issues. Detail of whether the issues were raised for information only, or required action to be taken was recorded, as was the outcome of this action.

RESULTS

A wide range of clinical and non-clinical issues (J1-J8), were identified. 23% (47) of the 207 issues were raised for information only. 77% (160) issues required action to be taken. 109 were dosed within 3 weeks. 23 took more than 3 weeks to close. Eight weeks after the study period 28 issues were still being actively resolved. 85% of JTCCC teleconferences had full participation from both theatres. Technical difficulties and/or the treatment of casualties prevented the participation of one or both theatres on 9 occasions.

CONCLUSIONS

JTCCC supports deployed clinicians and enables rapid resolution of issues affecting combat casualty care. It is limited by its focus on UK casualties only. Although intended as a Clinical Governance tool the evidence of this review is that JTCCC has wider effects in a number of clinical and non-clinical areas.

Military pre-hospital care: why is it different?

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

What is the ideal pre-hospital analgesic?--a questionnaire study

AIM

To determine clinical opinion of effectiveness of current battlefield analgesia and the realistic options to improve future analgesia in hostile environments.

METHODS

Structured electronic questionnaire distributed to selected individuals in UK and on operations.

POPULATION

122 UK Defence Medical Services and US Medical Corps doctors, nurses and combat medical technicians involved in the early management of severe trauma on deployment.

RESULTS

54 (44%) agreed and 63 (52%) disagreed that intramuscular morphine had the ideal analgesic properties for the military pre-hospital environment. Over half of those with operational experience reported multiple instances of intramuscular morphine providing inadequate analgesia. 86 (70%) desired a more potent analgesic than morphine in the first hour following injury. 101 (83%) identified simplicity and reliability of use by a soldier as of high importance. 99 (81%) identified rapid onset of action of high importance. With regard to an acceptable route of drug self-administration, 88 (72%) supported a nasal spray; 78 (64%) supported a sustained release buccal tablet (adhesive to the gum); 61 (50%) supported a disposable inhaler of volatile gas (although 91% had no experience of the currently available drug in this formulation); and 55 (45%) supported a skin patch.

CONCLUSION

Intramuscular morphine does not meet the needs of the majority of clinical stakeholders. Alternative routes of self-administration are acceptable, but support for available commercial solutions is clouded by incomplete awareness. Anaesthetists and emergency physicians desire a multimodal approach to battlefield analgesia within the evacuation chain.

Intra-osseous access (EZ-IO) for resuscitation: UK military combat experience

Military trauma produces predominantly blast and fragmentation injury, commonly resulting in haemorrhagic shock. Injury patterns to limbs are such that the conventional sites for venous cannulation may be unsuitable. The EZ-IO (Vidacare, San Antonio) system is one of a number of novel products designed for intraosseous (IO) access in adults or children. In three months of combat casualty care in Helmand Province, Afghanistan, the UK Defence Medical Services used EZ-IO for emergency vascular access on 26 patients (16 adults; 10 children). 23/26 patients had IO access obtained in the emergency department; 3/26 had pre-hospital IO access within a tactically flying helicopter. A total of 32 needles were inserted, with 97% effective function. IO needles were used to administer fluid (crystalloid, packed red cells and fresh frozen plasma) and drugs (analgesics, cardiac arrest drugs, antibiotics, drugs for both rapid sequence induction and maintenance of anaesthesia). No complication of infection was noted, but pain was observed in responsive patients with the pain of infusion exceeding that of the underlying injuries in 3 cases.

A Realistic Model for Catastrophic External Haemorrhage Training

External haemorrhage is a significant cause of combat morbidity and mortality. UK DMS have introduced topical haemostatic agents (HemCon, QuikClot) for use as an adjunct to control catastrophic external haemorrhage. Realistic training in new equipment is essential. A model is described that is simple, reproducible, valid, realistic and currently unique in its opportunity to train soldiers to deal with life-threatening external bleeding, without recourse to live animal training. The model has been used successfully to train UK DMS medics, nurses and doctors in Afghanistan.

Medium-Fidelity Medical Simulators: Use in a Pre-Hospital,Operational, Military Environment

On Operation Telic 6, the UK Med Group consisting of 3 Close Support Medical Regiment and 205 Field Hospital (Volunteers) deployed to provide medical support to coalition forces in Iraq. Personnel were drawn from Regular and Territorial Units, plus additional medical support from Armies of the Czech Republic and Denmark. The efficient delivery of operational emergency medical care hinged upon the successful integration of personnel from these units. We report on the use of a medium-fidelity simulator, in a pre-hospital and hospital environment over a three month period on an operational tour. In conducting 42 exercises (12 of which commenced in a pre-hospital environment), we have demonstrated the feasibility of the system in rehearsing the management of the major trauma patient. This training was used to enhance teamwork, identify system deficiencies and practise solutions in a safe environment. This paper discusses our experiences in relation to the current literature on this expanding area of trauma training.

Training For Overseas Operational Deployments And The DMCC

Through the DMCC and similar comprehensive training, Military and NGO personnel can prepare for deployment with a greater understanding of the issues that will confront them whilst there. Progression through the modules will provide them with a greater skill set to meet the challenges that await them and allow them to be an effective and valuable member of the team.

Entrapment, extrication and immobilization

Management of the trapped casualty is a specialized area of prehospital care. It requires close cooperation between all the emergency services. Specific training courses are being developed in the UK for both rescue and medical terms. When approaching an entrapment incident medical teams must consider their own safety and liaise closely with the paramedical and rescue crews as to the best means of effecting casualty release. A variety of immobilization equipment is available, different equipment being suitable to different situations. The prehospital anaesthetist needs to understand the influence this equipment has on airway management and subsequent anaesthesia.

Successful resuscitation from sea water drowning

A case of a 24-year-old male who survived a near drowning despite suboptimal pre-hospital management is reported. The case illustrates the value of continuing resuscitative efforts even in the apparently dead drowning victim.

The Gulf war: anaesthetic experience at 32 Field Hospital Department of Anaesthesia and Resuscitation

The organisation and the workload of the anaesthetic department of a Field Hospital deployed during the Gulf war were described. Suggestions are made as to how the problems encountered might be overcome in the future.