Dysregulation of the actin scavenging system and inhibition of DNase activity following severe thermal injury.

BACKGROUND: Circulating cell-free DNA (cfDNA) is not found in healthy subjects, but is readily detected after thermal injury and may contribute to the risk of multiple organ failure. The hypothesis was that a postburn reduction in DNase protein/enzyme activity could contribute to the increase in cfDNA following thermal injury. METHODS: Patients with severe burns covering at least 15 per cent of total body surface area were recruited to a prospective cohort study within 24 h of injury. Blood samples were collected from the day of injury for 12 months. RESULTS: Analysis of blood samples from 64 patients revealed a significant reduction in DNase activity on days 1-28 after injury, compared with healthy controls. DNase protein levels were not affected, suggesting the presence of an enzyme inhibitor. Further analysis revealed that actin (an inhibitor of DNase) was present in serum samples from patients but not those from controls, and concentrations of the actin scavenging proteins gelsolin and vitamin D-binding protein were significantly reduced after burn injury. In a pilot study of ten military patients with polytrauma, administration of blood products resulted in an increase in DNase activity and gelsolin levels. CONCLUSION: The results of this study suggest a novel biological mechanism for the accumulation of cfDNA following thermal injury by which high levels of actin released by damaged tissue cause a reduction in DNase activity. Restoration of the actin scavenging system could therefore restore DNase activity, and reduce the risk of cfDNA-induced host tissue damage and thrombosis.

ANTECEDENTES: El ADN libre de las células circulantes (circulating cell-free DNA, cfDNA) no se encuentra en sujetos sanos, pero se detecta fácilmente después de una lesión térmica y puede contribuir al riesgo de fallo multiorgánico. La hipótesis fue que una disminución en la actividad de la proteína/enzima ADNasa tras la lesión térmica podría contribuir a la elevación del cfDNA que ocurre tras la misma. MÉTODOS: Los pacientes con quemaduras graves con una extensión ≥ 15% del área de superficie corporal total (total body surface area, TBSA) se incluyeron en un estudio prospectivo de cohortes durante las primeras 24 horas posteriores a la lesión. Se recogieron muestras de sangre desde el día de la lesión hasta los 12 meses posteriores a la misma. RESULTADOS: El análisis de muestras de sangre de 64 pacientes reveló una reducción significativa de la actividad de la ADNasa en los días 1 a 28 después de la lesión, en comparación con los controles sanos. Los niveles de proteína ADNasa no se vieron afectados, lo que sugiere la presencia de un inhibidor enzimático. Un análisis adicional reveló que la actina (un inhibidor de la ADNasa) estaba presente en las muestras de suero de los pacientes, pero no en los controles, y las concentraciones de la gelsolina, proteína que causa la disociación de la actina, y la proteína de unión a la vitamina D se redujeron significativamente después de la lesión térmica. En un estudio piloto de 10 pacientes con politrauma por lesiones militares, la administración de hemoderivados produjo un aumento en la actividad de la ADNasa y de los niveles de gelsolina. CONCLUSIÓN: Este estudio sugiere un nuevo mecanismo biológico para la acumulación de cfDNA después de una lesión térmica, por el cual los altos niveles de actina liberada por el tejido dañado causarían una reducción en la actividad de la ADNasa. La restauración del sistema eliminador de actina podría, por lo tanto, restaurar la actividad de la ADNasa y reducir el riesgo de daño tisular y trombosis en el huésped inducido por el cfDNA.

The effects of acute hypoxia on tissue oxygenation and circulating alarmins in healthy adults.

The binding of high-mobility group box-1 (HMGB-1) to the membrane receptor for advanced glycation end-products (mRAGE) is a key early mediator of non-infectious inflammation and its triggers include ischaemia/hypoxia. The effects of acute hypoxia on soluble RAGE (sRAGE) are unknown. Fourteen healthy adults (50 % women; 26.6+/-3.8 years) were assessed at baseline normoxia (T0), followed by four time-points (T90, 95, 100 and 180 min) over three hours of continuous normobaric hypoxia (NH, 4,450 m equivalent) and again 60 min after return to normoxia (T240). A 5-min exercise step test was performed during NH at T90. Plasma concentrations of HMGB-1, sRAGE VCAM-1, ICAM-1, VEGF IL-8 and IL-13 were measured using venous blood. Arterial and tissue oxygen saturations were measured using pulse oximetry (SpO(2)) and near-infrared spectroscopy (StO(2)), respectively. NH led to a significant reduction in SpO(2), StO(2), sRAGE and VEGF, which was compounded by exercise, before increasing to baseline values with normoxic restoration (T240). NH-exercise led to a paired increase in HMGB-1. sRAGE inversely correlated with HMGB-1 (r=-0.32; p=0.006), heart rate (r=-0.43; p=0.004) but was not linked to SpO(2) or StO(2). In conclusion, short-term NH leads to a fall in sRAGE and VEGF concentrations with a transient rise post NH-exercise in HMGB-1.

RePHILL: protocol for a randomised controlled trial of pre-hospital blood product resuscitation for trauma.

OBJECTIVES: To describe the 'Resuscitation with Pre-HospItaL bLood products' trial (RePHILL) - a multi-centre randomised controlled trial of pre-hospital blood product (PHBP) administration vs standard care for traumatic haemorrhage. BACKGROUND: PHBP are increasingly used for pre-hospital trauma resuscitation despite a lack of robust evidence demonstrating superiority over crystalloids. Provision of PHBP carries additional logistical and regulatory implications, and requires a sustainable supply of universal blood components. METHODS: RePHILL is a multi-centre, two-arm, parallel group, open-label, phase III randomised controlled trial currently underway in the UK. Patients attended by a pre-hospital emergency medical team, with traumatic injury and hypotension (systolic blood pressure <90 mmHg or absent radial pulse) believed to be due to traumatic haemorrhage are eligible. Exclusion criteria include age <16 years, blood product receipt on scene prior to randomisation, Advanced Medical Directive forbidding blood product administration, pregnancy, isolated head injury and prisoners. A total of 490 patients will be recruited in a 1 : 1 ratio to receive either the intervention (up to two units of red blood cells and two units of lyophilised plasma) or the control (up to four boluses of 250 mL 0.9% saline). The primary outcome measure is a composite of failure to achieve lactate clearance of ≥20%/h over the first 2 hours after randomisation and all-cause mortality between recruitment and discharge from the primary receiving facility to non-acute care. Secondary outcomes include pre-hospital time, coagulation indices, in-hospital transfusion requirements and morbidity. RESULTS: Pilot study recruitment began in December 2016. Approval to proceed to the main trial was received in June 2017. Recruitment is expected to continue until 2020. CONCLUSIONS: RePHILL will provide high-quality evidence regarding the efficacy and safety of PHBP resuscitation for trauma.

Decompressive craniectomy and cranioplasty: experience and outcomes in deployed UK military personnel.

OBJECT: In recent conflicts, many UK personnel sustained head injuries requiring damage-control surgery and aeromedical transfer to the UK. This study aims to examine indications, complications and outcomes of UK military casualties undergoing craniectomy and cranioplasty from conflicts in Afghanistan and Iraq. METHODS: The UK military Joint Theatre Trauma Registry (JTTR) was searched for all UK survivors in Afghanistan and Iraq between 2004 and 2014 requiring craniectomy and cranioplasty resulting from trauma. RESULTS: Fourteen decompressive craniectomies and cranioplasties were performed with blast and gunshot wounds equally responsible for head injury. Ten survivors (71%) had an Injury Severity Score (ISS) of 75, normally designated as 'unsurvivable'. Most were operated on the day of injury. Seventy-one percent received a reverse question mark incision and 7% received a bicoronal incision. Seventy-nine percent had bone flaps discarded. Overall infection rate was 43%. Acinetobacter spp was the causative organism in 50% of cases. Median Glasgow Outcome Scale (GOS) at final follow-up was 4. All casualties had a GOS score greater than 3. CONCLUSIONS: Timely neurosurgical intervention is imperative for military personnel given high survival rates in those sustaining what are designated 'un-survivable' injuries. Early decompression facilitates safe aeromedical evacuation of casualties. Excellent outcomes validate the UK military trauma system and the stepwise performance gains throughout recent conflicts however trauma registers most evolving to have specific relevance to military casualties. In high-energy trauma with contamination and soft-tissue destruction, surgery should be conducted with regard for future soft tissue reconstruction. Bone flaps should be discarded and cranioplasty performed according to local preference. Facilities receiving military casualties should have specialist microbiological input mindful of the difficulties treating unusual microbes.

British Military surgical key performance indicators: time for an update?

BACKGROUND: Key performance indicators (KPIs) are metrics that compare actual care against an ideal structure, process or outcome standard. KPIs designed to assess performance in deployed military surgical facilities have previously been published. This study aimed to review the overall performance of surgical trauma care for casualties treated at Role 3 Camp Bastion, Medical Treatment Facility, Afghanistan, in light of the existing Defence Medical Services (DMS) KPIs. The secondary aims were to assess the utility of the surgical KPIs and make recommendations for future surgical trauma care review. METHODS: Data on 22 surgical parameters were prospectively collected for 150 injured patients who had primary surgery at Camp Bastion between 1 May 2013 and 20 August 2013. Additional information for these patients was obtained using the Joint Theatre Trauma Register. The authors assessed data recording, applicability and compliance with the KPIs. RESULTS: Median data recording was 100% (IQR 98%-100%), median applicability was 56% (IQR 10%-99%) and median compliance was 78% (IQR 58%-93%). One KPI was not applicable to any patient in our population. Eleven KPIs achieved >80% compliance, five KPIs had 80%-60% compliance and five KPIs had <60% compliance. Recommendations are made for minor modifications to the current KPIs. CONCLUSION: 78% compliance with the DMS KPIs provides a snapshot of the performance of the surgical aspect of military trauma care in 2013. The KPIs highlight areas for improvement in service delivery. Individual KPI development should be driven by evidence and reflect advances in practice and knowledge. A method of stakeholder consultation, and sequential refinement following evidence review, may be the right process to develop the future set of DMS KPIs.

Maintaining surgical skills for military general surgery: the potential role for multivisceral organ retrieval in military general surgery training and practice.

The closure of the Medical Treatment facility in Camp BASTION and the return to contingency operations presents a new challenge in training and maintaining the skills of military surgeons. Multivisceral organ retrieval presents a unique opportunity to practice some of the more unusual techniques required in military surgery in the National Health Service. This article details the experience that organ retrieval offers and matches this to the needs of military surgeons. National Organ Retrieval Service teams need skilled surgeons, and a mutually beneficial partnership is in prospect.

Human factors in decision making in major trauma in Camp Bastion, Afghanistan.

INTRODUCTION: The concentration of major trauma experience at Camp Bastion has allowed continuous improvements to occur in the patient pathway from the point of wounding to surgical treatment. These changes have involved clinical management as well as alterations to the physical layout of the hospital, training and decision making. Consideration of the human factors has been a major part of these improvements. METHODS: We describe the Camp Bastion patient pathway with the communication template that focused decision making at various key moments during damage control resuscitation and damage control surgery (DCR-DCS). This system identifies four key stages: 'command huddle', 'snap brief', 'sit-reps' (situation reports) and 'sign-out/debrief'. The attitude of staff to communication and decision making is also evaluated. RESULTS: Twenty cases admitted to Camp Bastion with battlefield injuries were studied from 6 September to 6 October 2012. Qualitative responses from 115 members of staff were collected. All patients were haemodynamically shocked with a median pH of 7.25 (range: 6.83-7.40) and a median of 18 units of mixed red cells and plasma were transfused. In 89% of instances, theatre staff were aware of what was required of them at the beginning of the case, 86% felt there were regular updates and 93% understood what was required of them as the case progressed. CONCLUSIONS: The evolution of the hospital at Camp Bastion has been a unique learning experience in the field of major trauma. The Defence Medical Services have responded with continuous innovation to optimise DCR-DCS for seriously injured patients. Together with the improvements in clinical care, a communication and decision making matrix was developed. Staff evaluation showed a high degree of satisfaction with the quality of communication.

A survey of major trauma centre staffing in England.

INTRODUCTION: Trauma care delivery in England has been transformed by the development of trauma networks, and the designation of trauma centres. A specialist trauma service is a key component of such centres. The aim of this survey was to determine to which extent, and how, the new major trauma centres (MTCs) have been able to implement such services. METHODS: Electronic questionnaire survey of MTCs in England. RESULTS: All 22 MTCs submitted responses. Thirteen centres have a dedicated major trauma service or trauma surgery service, and a further four are currently developing such a service. In 7 of these 17 centres, the service is or will be provided by orthopaedic surgeons, in 2 by emergency medicine departments, in another 2 by general or vascular surgeons, and in 6 by a multidisciplinary group of consultants. DISCUSSION: A large proportion of MTCs still do not have a dedicated major trauma service. Furthermore, the models which are emerging differ from other countries. The relative lack of involvement of surgeons in MTC trauma service provision is particularly noteworthy, and a potential concern. The impact of these different models of service delivery is not known, and warrants further study.

An evaluation of the normal range of StO2measurements at rest and following a mixed exercise protocol.

BACKGROUND: Assessment of local tissue oxygenation (StO2) using near infrared spectroscopy is an emerging technique in medical practice with applications in trauma/sepsis management, diagnosis of acute compartment syndrome and assessment of tissue viability. Despite this, there have been little published data on the range of StO2values in normal subjects. METHODS: StO2measurements were recorded in 105 infantry soldiers using an INVOS System Monitor (Somanetics) from both deltoids, the anterior compartment of the leg and the frontal lobe of the brain. Measurements were taken at rest and following completion of a mixed exercise protocol, consisting of overarm pull-ups, sit-ups and a 3-mile run. RESULTS: StO2values at rest were found to have a wide normal range with a skew left distribution. Mean StO2was similar between the deltoids (left deltoid 80%, right deltoid 79%), but significantly different between other anatomical sites (leg 68%, brain 73%). However, all sites demonstrated a similar lower range cut-off at approximately 40%. Following exercise, there was a significant increase in StO2values at all sites (left deltoid by 3.1 ± 2.0%, right deltoid by 2.6 ± 2.3%, leg by 8.0 ± 2.3% and brain by 8.6 ± 1.9%), which persisted for at least 10 min. CONCLUSIONS: There were statistically significant differences in mean StO2values recorded at different anatomical sites, although the reference ranges were wide and substantially overlapped. StO2increased at all sites after exercise with the effect persisting for at least 10 min. The interaction between exercise and pathological phenomena remains unknown and is an area for further study.

Defining combat helmet coverage for protection against explosively propelled fragments.

INTRODUCTION: Prevention against head wounds from explosively propelled fragments is currently the Mark 7 general service combat helmet, although only limited evidence exists to define the coverage required for the helmet to adequately protect against such a threat. The Royal Centre for Defence Medicine was tasked by Defence Equipment and Support to provide a framework for determining the optimum coverage of future combat helmets in order to inform the VIRTUS procurement programme. METHOD: A systematic review of the literature was undertaken to identify potential solutions to three components felt necessary to define the ideal helmet coverage required for protection against explosively propelled fragments. RESULTS: The brain and brainstem were identified as the structures requiring coverage by a helmet. No papers were identified that directly defined the margins of these structures to anatomical landmarks, nor how these could be related to helmet coverage. CONCLUSIONS: We recommend relating the margins of the brain to three identifiable anatomical landmarks (nasion, external auditory meatus and superior nuchal line), which can in turn be related to the coverage provided by the helmet. Early assessments using an anatomical mannequin indicate that the current helmet covers the majority of the brain and brainstem from projectiles with a horizontal trajectory but not from ones that originate from the ground. Protection from projectiles with ground-originating trajectories is reduced by helmets with increased stand-off from the skin. Future helmet coverage assessments should use a finite element numerical modelling approach with representative material properties assigned to intracranial anatomical structures to enable differences in projectile trajectory and helmet coverage to be objectively compared.

Demonstrating the effectiveness of body armour: a pilot prospective computerised surface wound mapping trial performed at the Role 3 hospital in Afghanistan.

INTRODUCTION: Modern body armour clearly reduces injury incidence and severity, but evidence to actually objectively demonstrate this effect is scarce. Although the Joint Theatre Trauma Registry (JTTR) alone cannot relate injury pattern to body armour coverage, the addition of computerised Surface Wound Mapping (SWM) may enable this utility. METHOD: Surface wound locations of all UK and NATO coalition soldiers, Afghan National Army and Police and local nationals injured by explosively propelled fragments and treated in the Role 3 UK-led Field Hospital in Camp Bastion, Afghanistan, between 8 July and 20 October 2012 were prospectively recorded. The Abbreviated Injury Scores (AIS) and relative risk of casualties sustaining injuries under a type of body armour were compared with those that did not wear that armour. RESULTS: Casualties wearing a combat helmet were 2.7 times less likely to sustain a fragmentation wound to the head than those that were unprotected (mean AIS of 2.9 compared with 4.1). Casualties wearing a body armour vest were 4.1 times less likely to sustain a fragmentation wound to the chest or abdomen than those that were unprotected (mean AIS of 2.9 compared with 3.9). Casualties wearing pelvic protection were 10 times less likely to sustain a fragmentation wound to the pelvis compared with those that were unprotected (mean AIS of 3.4 compared with 3.9). DISCUSSION: Computerised SWM has objectively demonstrated the ability of body armour worn on current operations in Afghanistan to reduce wound incidence and severity. We recognise this technique is limited in that it only records the surface wound location and may be specific to this conflict. However, gathering electronic SWM at the same time as recording injuries for the JTTR was simple, required little extra time and therefore we would recommend its collection during future conflicts.

Mortality, survival and residual injury burden of Royal Navy and Royal Marine combat casualties sustained in 11-years of operations in Iraq and Afghanistan.

We present eleven years of prospectively-gathered data defining the full spectrum of the United Kingdom's (UK) Naval Service (Royal Navy and Royal Marines) casualties, and characterise the injury patterns, recovery and residual functional burden from the conflicts of the last decade. The UK Military Trauma Registry was searched for all Naval Service personnel injured between March 2003 and April 2013. These records were then cross-referenced with the records of the Naval Service Medical Board of Survey (NSMBOS), which evaluates injured Naval Service personnel for medical discharge, continued service in a reduced capacity or Return to Full Duty (RTD). Population at risk data was calculated from service records. There were 277 casualties in the study period: 63 (23%) of these were fatalities. Of the 214 survivors, 63 or 29% (23% of total) were medically discharged; 24 or 11% (9% of total) were placed in a reduced fitness category with medical restrictions placed on their continued military service. A total of 127 individuals (46% of the total and 59% of survivors) RTD without any restriction. The greatest number of casualties was sustained in 2007. There was a 3% casualty risk per year of operational service for Naval Service personnel. The most common reason cited by Naval Service Medical Board of Survey (NSMBOS) for medical downgrading or discharge was injury to the lower limb, with upper limb trauma the next most frequent. This study characterises the spectrum of injuries sustained by the Naval Service during recent conflicts with a very high rate of follow-up. Extremity injuries pose the biggest challenge to reconstructive and rehabilitative services striving to maximise the functional outcomes of injured service personnel.

Prospective randomised controlled trial of nanocrystalline silver dressing versus plain gauze as the initial post-debridement management of military wounds on wound microbiology and healing.

INTRODUCTION: Recent conflicts have been characterised by the use of improvised explosive devices causing devastating injuries, including heavily contaminated wounds requiring meticulous surgical debridement. After being rendered surgical clean, these wounds are dressed and the patient transferred back to the UK for on-going treatment. A dressing that would prevent wounds from becoming colonised during transit would be desirable. The aim of this study was to establish whether using nanocrystalline silver dressings, as an adjunct to the initial debridement, would positively affect wound microbiology and wound healing compared to standard plain gauze dressings. METHODS: Patients were prospectively randomised to receive either silver dressings, in a nanocrystalline preparation (Acticoat™), or standard of care dressings (plain gauze) following their initial debridement in the field hospital. On repatriation to the UK microbiological swabs were taken from the dressing and the wound, and an odour score recorded. Wounds were followed prospectively and time to wound healing was recorded. Additionally, patient demographic data were recorded, as well as the mechanism of injury and Injury Severity Score. RESULTS: 76 patients were recruited to the trial between February 2010 and February 2012. 39 received current dressings and 37 received the trial dressings. Eleven patients were not swabbed. There was no difference (p=0.1384, Fishers) in the primary outcome measure of wound colonisation between the treatment arm (14/33) and the control arm (20/32). Similarly time to wound healing was not statistically different (p=0.5009, Mann-Whitney). Wounds in the control group were scored as being significantly more malodorous (p=0.002, Mann-Whitney) than those in the treatment arm. CONCLUSIONS: This is the first randomised controlled trial to report results from an active theatre of war. Performing research under these conditions poses additional challenges to military clinicians. Meticulous debridement of wounds remains the critical determinant in wound healing and infection and this study did not demonstrate a benefit of nanocrystaline silver dressing in respect to preventing wound colonisation or promoting healing, these dressings do however seem to significantly reduce the unpleasant odour commonly associated with battlefield wounds.

Outcome of penetrating intracranial injuries in a military setting.

BACKGROUND: Penetrating intracranial injuries are common in the deployed military medical environment. Early assessment of prognosis includes initial conscious level. There has been no previous identification of different outcomes depending on mechanism of penetrating injury. The aim of this study was to define outcome from penetrating head injury in our population, and to compare outcome between gunshot wound (GSW) and blast fragment injury, in order to detect a difference in survival. METHODS: A retrospective database review was undertaken using the UK Joint Theatre Trauma Registry (JTTR) between the dates 2003 and 2011 to identify all cases of penetrating head injury. Data collected included mechanism of injury, first recorded GCS, injury severity score (ISS), abbreviated injury scale (AIS) head score, concomitant extracranial injury, surgical intervention, hospital length of stay, and survival. RESULTS: 813 patients sustained a penetrating head injury, of whom 625 were injured by blast fragmentation and 188 were injured by GSW; overall 336 patients (41.3%) died. There was a significant difference between survival from GSW (41.5%) and blast fragment (63.8%; p<0.001). In addition, the GCS in patients injured by GSW was significantly lower than that in patients injured by blast fragment. 157 cases sustained isolated head injury (79 GSW, 78 blast). The difference in injury severity between these groups was marked; median AIS was higher in the GSW group, survival lower (42% vs. 88%; p<0.001) and distribution of GCS categories less favourable (p<0.001). 338 of 343 patients (98.5%) with a best recorded GCS>5, survived to discharge. CONCLUSION: Most patients who present following penetrating intracranial injury, who have a GCS>5, survive to discharge. There is a significant difference in survival to hospital discharge following penetrating injury caused by blast fragment compared to those caused by GSW, partly attributable to a difference in injury severity. This is the first study to specifically highlight and define this difference.

Changes in blood transfusion practices in the UK role 3 medical treatment facility in Afghanistan, 2008-2011.

OBJECTIVE: To document blood component usage in the UK medical treatment facility, Afghanistan, over a period of 4 years; and to examine the relationship with transfusion capability, injury pattern and survival. BACKGROUND: Haemostatic resuscitation is now firmly established in military medical practice, despite the challenges of providing such therapy in austere settings. MATERIALS AND METHODS: Retrospective study of blood component use in service personnel admitted for trauma. Data were extracted from the UK Joint Theatre Trauma Registry. RESULTS: A total of 2618 patients were identified. Survival increased from 76 to 84% despite no change in injury severity. The proportion of patients receiving blood components increased from 13 to 32% per annum; 417 casualties received massive transfusion (≥10 units of RCC), the proportion increasing from 40 to 62%. Use of all blood components increased significantly in severely injured casualties, to a median (IQR) of 16 (9-25) units of red cell concentrate (P = 0·006), 15 (8-24) of plasma (P = 0·002), 2 (0-5) of platelets (P < 0·001) and 1 (0-3) of cryoprecipitate (P < 0·001). Cryoprecipitate (P = 0·009) and platelet use (P = 0·005) also increased in moderately injured casualties. CONCLUSIONS: The number of blood components transfused to individual combat casualties increased during the 4-year period, despite no change in injury severity or injury pattern. Survival also increased. Combat casualties requiring massive transfusion have a significantly higher chance of survival than civilian patients. Survival is the product of the entire system of care. However, we propose that the changes in military transfusion practice and capability have contributed to increased combat trauma survival.

The challenges in developing a finite element injury model of the neck to predict the penetration of explosively propelled projectiles.

INTRODUCTION: Neck injuries sustained by UK service personnel serving on current operations from explosively propelled fragments result in significant mortality and long-term morbidity. Many of these injuries could potentially have been prevented had the soldiers been wearing their issued neck collars at the time of injury. The aim of this research is to develop an accurate method of predicting the resultant damage to cervical neurovascular structures from explosively propelled fragments. CURRENT STATUS: A finite element numerical model has been developed based on an anatomically accurate, anthropometrically representative 3D mathematical mesh of cervical neurovascular structures. Currently, the model simulates the passage of a fragment simulating projectile through all anatomical components of the neck using material models based upon 20% ballistic gelatin on the simplification that all tissue types act like homogenous muscle. FUTURE RESEARCH: The material models used to define the properties of each element within the model will be sequentially replaced by ones specific to each individual tissue within an anatomical structure. However, the cumulative effect of so many additional variables will necessitate experimental validation against both animal models and post-mortem human subjects to improve the credibility of any predictions made by the model. We believe this approach will in the future have the potential to enable objective comparisons between the mitigative effects of different body armour systems to be made with resultant time and financial savings.

Damage control - trauma care in the first hour and beyond: a clinical review of relevant developments in the field of trauma care.

INTRODUCTION: Trauma provision in the UK is a topic of interest. Regional trauma networks and centres are evolving and research is blossoming, but what bearing does all this have on the care that is delivered to the individual patient? This article aims to provide an overview of key research concepts in the field of trauma care, to guide the clinician in decision making in the management of major trauma. METHODS: The Ovid MEDLINE(®), EMBASE™ and PubMed databases were used to search for relevant articles on haemorrhage control, damage control resuscitation and its exceptions, massive transfusion protocols, prevention and correction of coagulopathy, acidosis and hypothermia, and damage-control surgery. FINDINGS: A wealth of research is available and a broad range has been reviewed to summarise significant developments in trauma care. Research has been categorised into disciplines and it is hoped that by considering each, a tailored management plan for the individual trauma patient will evolve, potentially improving patient outcome.

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

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

Developing a cumulative anatomic scoring system for military perineal and pelvic blast injuries.

BACKGROUND: Improvised explosive device (IED) yields in Afghanistan have increased resulting in more proximal injuries. The injury severity score (ISS) is an anatomic aggregate score of the three most severely injured anatomical areas but does not accurately predict severity in IED related pelvi-perineal trauma patients. A scoring system based on abbreviated injury score (AIS) was developed to reflect the severity of these injuries in order to better understand risk factors, develop a tool for future audit and improve performance. METHOD: Using standard AIS descriptors, injury scales were constructed for the pelvis (1, minor to 6, maximal). The perineum was divided into anterior and posterior zones as relevant to injury patterns and blast direction with each soft tissue structure being allocated a score from its own severity scale. A cumulative score, from 1 to 36 for soft tissue, or a maximum of 42 if a pelvic fracture was involved, was created for all structures injured in the anterior and posterior zones. RESULTS: Using this new scoring system, 77% of patients survived with a pelvi-perineal trauma score (PPTS) below 5. There was a significant increase in mortality, number of pelvic fractures and amputations with increase in score when comparing the first group (score 1-5) to the second group (score 6-10). For scores between 6 and 16 survival was 42% and 22% for scores between 17 and 21. In our cohort of 62 survivors, 1 patient with an IED related pelvi-perineal injury had a 'theoretically un-survivable' maximal ISS of 75 and survived, whereas there were no survivors with a PPTS greater than 22 but this group had no-one with an ISS of 75 suggesting ISS is not an accurate reflection of the true severity of pelvi-perineal blast injury. CONCLUSIONS: This scoring system is the initial part of a more complex logistic regression model that will contribute towards a unique trauma scoring system to aid surgical teams in predicting fluid requirements and operative timelines. In austere environments, it may also help to prevent futile resuscitations. Better correlation between measurement of severity and outcome would aid performance improvement monitoring. In the longer term it will also allow benchmarking of current survival rates and comparisons in the future.