Outcomes of UK military personnel treated with ice cold water immersion for exertional heat stroke

INTRODUCTION

Despite mitigation efforts, exertional heat stroke (EHS) is known to occur in military personnel during training and operations. It has significant potential to cause preventable morbidity and mortality. International consensus from sports medicine organisations supports treating EHS with early rapid cooling by immersing the casualty in cold water. However, evidence remains sparse and the practice is not yet widespread in the UK.

METHODS

Following changes to enable on-site ice cold water immersion (ICWI) at the Royal Marines Commando Training Centre, Lympstone, UK, we prospectively gathered data on 35 patients treated with ICWI over a 3-year period. These data included the incidence of adverse events (e.g. death, cardiac arrest or critical care admission) as the primary outcome. Basic anthropometric data, cooling rates achieved and biochemical and haematological test results on days 0-5 were also gathered and analysed.

RESULTS

Despite being a cohort of patients in whom we might expect significant morbidity and mortality based on the severity of EHS at presentation, none experienced a serious adverse event. In this cohort with rapid initiation of effective cooling, biochemical derangement appeared less severe than that reported in previous studies. Higher body mass index (BMI) was associated with a lower cooling rate across a range of values previously reported as potentially of clinical significance.

CONCLUSIONS

This case series supports recent updates to UK military guidance that ICWI should be more widely adopted for the treatment of EHS. Clinicians should be aware of likely patterns of blood test abnormalities in the days following EHS. Further work should seek to establish the impact of lower rates of cooling and develop strategies to optimise cooling in patients with higher BMI.

The accuracy of prehospital triage decisions in English trauma networks - a case-cohort study

BACKGROUND

Care for injured patients in England is provided by inclusive regional trauma networks. Ambulance services use triage tools to identify patients with major trauma who would benefit from expedited Major Trauma Centre (MTC) care. However, there has been no investigation of triage performance, despite its role in ensuring effective and efficient MTC care. This study aimed to investigate the accuracy of prehospital major trauma triage in representative English trauma networks.

METHODS

A diagnostic case-cohort study was performed between November 2019 and February 2020 in 4 English regional trauma networks as part of the Major Trauma Triage Study (MATTS). Consecutive patients with acute injury presenting to participating ambulance services were included, together with all reference standard positive cases, and matched to data from the English national major trauma database. The index test was prehospital provider triage decision making, with a positive result defined as patient transport with a pre-alert call to the MTC. The primary reference standard was a consensus definition of serious injury that would benefit from expedited major trauma centre care. Secondary analyses explored different reference standards and compared theoretical triage tool accuracy to real-life triage decisions.

RESULTS

The complete-case case-cohort sample consisted of 2,757 patients, including 959 primary reference standard positive patients. The prevalence of major trauma meeting the primary reference standard definition was 3.1% (n=54/1,722, 95% CI 2.3 - 4.0). Observed prehospital provider triage decisions demonstrated overall sensitivity of 46.7% (n=446/959, 95% CI 43.5-49.9) and specificity of 94.5% (n=1,703/1,798, 95% CI 93.4-95.6) for the primary reference standard. There was a clear trend of decreasing sensitivity and increasing specificity from younger to older age groups. Prehospital provider triage decisions commonly differed from the theoretical triage tool result, with ambulance service clinician judgement resulting in higher specificity.

CONCLUSIONS

Prehospital decision making for injured patients in English trauma networks demonstrated high specificity and low sensitivity, consistent with the targets for cost-effective triage defined in previous economic evaluations. Actual triage decisions differed from theoretical triage tool results, with a decreasing sensitivity and increasing specificity from younger to older ages.

Fine-scale spatiotemporal variations in bacterial community diversity in agricultural pond water

Microbial communities in surface waters are affected by environmental conditions and can influence changes in water quality. To explore the hypothesis that the microbiome in agricultural waters associates with spatiotemporal variations in overall water quality and, in turn, has implications for resource monitoring and management, we characterized the relationships between the microbiota and physicochemical properties in a model irrigation pond as a factor of sampling time (i.e., 9:00, 12:00, 15:00) and location within the pond (i.e., bank vs. interior sites and cross-sectional depths at 0, 1, and 2 m). The microbial communities, which were defined by 16S rRNA gene sequencing analysis, significantly varied based on all sampling factors (PERMANOVA P < 0.05 for each). While the relative abundances of dominant phyla (e.g., Proteobacteria and Bacteroidetes) were relatively stable throughout the pond, subtle yet significant increases in α-diversity were observed as the day progressed (ANOVA P < 0.001). Key water quality properties that also increased between the morning and afternoon (i.e., pH, dissolved oxygen, and temperature) positively associated with relative abundances of Cyanobacteria, though were inversely proportional to Verrucomicrobia. These properties, among additional parameters such as bioavailable nutrients (e.g., NH3, NO3, PO4), chlorophyll, phycocyanin, conductivity, and colored dissolved organic matter, exhibited significant relationships with relative abundances of various bacterial genera as well. Further investigation of the microbiota in underlying sediments revealed significant differences between the bank and interior sites of the pond (P < 0.05 for α- and β-diversity). Overall, our findings emphasize the importance of accounting for time of day and water sampling location and depth when surveying the microbiomes of irrigation ponds and other small freshwater sources.

Optimisation of mitochondrial function as a novel target for resuscitation in haemorrhagic shock: a systematic review

INTRODUCTION

Traumatic injury is one of the leading causes of death worldwide, and despite significant improvements in patient care, survival in the most severely injured patients remains unchanged. There is a crucial need for innovative approaches to improve trauma patient outcomes; this is particularly pertinent in remote or austere environments with prolonged evacuation times to definitive care. Studies suggest that maintenance of cellular homeostasis is a critical component of optimal trauma patient management, and as the cell powerhouse, it is likely that mitochondria play a pivotal role. As a result, therapies that optimise mitochondrial function could be an important future target for the treatment of critically ill trauma patients.

METHODS

A systematic review of the literature was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol to determine the potential role of mitochondria in traumatic injury and haemorrhagic shock (HS) and to identify current evidence for mitochondrial optimisation therapies in trauma. Articles were included if they assessed a mitochondrial targeted therapy in comparison to a control group, used a model of traumatic injury and HS and reported a method to assess mitochondrial function.

RESULTS

The search returned 918 articles with 37 relevant studies relating to mitochondrial optimisation identified. Included studies exploring a range of therapies with potential utility in traumatic injury and HS. Therapies were categorised into the key mitochondrial pathways impacted following traumatic injury and HS: ATP levels, cell death, oxidative stress and reactive oxygen species.

CONCLUSION

This systematic review provides an overview of the key cellular functions of the mitochondria following traumatic injury and HS and identifies why mitochondrial optimisation could be a viable and valuable target in optimising outcome in severely injured patients in the future.

Haemostatic resuscitation in practice: a descriptive analysis of blood products administered during Operation HERRICK, Afghanistan

INTRODUCTION

Life-threatening haemorrhage is the leading cause of potentially survivable injury in battlefield casualties. During Operation HERRICK (Afghanistan), mortality rates improved year on year due to a number of advances in trauma care, including haemostatic resuscitation. Blood transfusion practice has not previously been reported in detail during this period.

METHODS

A retrospective analysis of blood transfusion at the UK role 3 medical treatment facility (MTF) at Camp Bastion between March 2006 and September 2014 was performed. Data were extracted from two sources: the UK Joint Theatre Trauma Registry (JTTR) and the newly established Deployed Blood Transfusion Database (DBTD).

RESULTS

3840 casualties were transfused 72 138 units of blood and blood products. 2709 adult casualties (71%) were fully linked with JTTR data and were transfused a total of 59 842 units. Casualties received between 1 unit and 264 units of blood product with a median of 13 units per patient. Casualties wounded by explosion required almost twice the volume of blood product transfusion as those wounded by small arms fire or in a motor vehicle collision (18 units, 9 units, and 10 units, respectively). More than half of blood products were transfused within the first 2 hours following arrival at the MTF. There was a trend towards balanced resuscitation with more equal ratios of blood and blood products being used over time.

CONCLUSION

This study has defined the epidemiology of blood transfusion practice during Operation HERRICK. The DBTD is the largest combined trauma database of its kind. It will ensure that lessons learnt during this period are defined and not forgotten; it should also allow further research questions to be answered in this important area of resuscitation practice.

Evolution of the deployed medical director role in an era of contingency operations: reflections from a United Nations operation

This paper examines the development and evolution of the deployed medical director (DMD) role and argues for the re-establishment of a formal selection process and training pathway. Recent deployments into new areas of operations, deployment of smaller medical treatment facilities (MTFs), the reduced numbers of deployments for clinicians, working with various multinational partners and both military and civilian organisations all pose specific problems for DMDs. The initial and then continued deployment of a secondary care role 2 MTF as part of the United Nations Mission in South Sudan illustrated some of these challenges. Although a novel operation, the broad categories of these new challenges were similar to the historical challenges facing the first DMDs in Afghanistan. Corporate memory loss may be unavoidable to some degree due to rapid turnover in appointments, particularly in single service and joint headquarters. However, individual memory and experience remains extant within the military medical deployable workforce. After the cessation of UK military deployed hospital care involvement in Afghanistan, the UK DMD formal training pathway ended. This paper argues for the re-establishment of a more formal DMD selection process and training pathway to ensure that organisational learning is optimised.

Intraseasonal variation of phycocyanin concentrations and environmental covariates in two agricultural irrigation ponds in Maryland, USA

Recently, cyanobacteria blooms have become a concern for agricultural irrigation water quality. Numerous studies have shown that cyanotoxins from these harmful algal blooms (HABs) can be transported to and assimilated into crops when present in irrigation waters. Phycocyanin is a pigment known only to occur in cyanobacteria and is often used to indicate cyanobacteria presence in waters. The objective of this work was to identify the most influential environmental covariates affecting the phycocyanin concentrations in agricultural irrigation ponds that experience cyanobacteria blooms of the potentially toxigenic species Microcystis and Aphanizomenon using machine learning methodology. The study was performed at two agricultural irrigation ponds over a 5-month period in the summer of 2018. Phycocyanin concentrations, along with sensor-based and fluorometer-based water quality parameters including turbidity (NTU), pH, dissolved oxygen (DO), fluorescent dissolved organic matter (fDOM), conductivity, chlorophyll, color dissolved organic matter (CDOM), and extracted chlorophyll were measured. Regression tree analyses were used to determine the most influential water quality parameters on phycocyanin concentrations. Nearshore sampling locations had higher phycocyanin concentrations than interior sampling locations and "zones" of consistently higher concentrations of phycocyanin were found in both ponds. The regression tree analyses indicated extracted chlorophyll, CDOM, and NTU were the three most influential parameters on phycocyanin concentrations. This study indicates that sensor-based and fluorometer-based water quality parameters could be useful to identify spatial patterns of phycocyanin concentrations and therefore, cyanobacteria blooms, in agricultural irrigation ponds and potentially other water bodies.

Killed in action (KIA): an analysis of military personnel who died of their injuries before reaching a definitive medical treatment facility in Afghanistan (2004-2014)

INTRODUCTION

The majority of combat deaths occur before arrival at a medical treatment facility but no previous studies have comprehensively examined this phase of care.

METHODS

The UK Joint Theatre Trauma Registry was used to identify all UK military personnel who died in Afghanistan (2004-2014). These data were linked to non-medical tactical and operational records to provide an accurate timeline of events. Cause of death was determined from records taken at postmortem review. The primary objective was to report time between injury and death in those killed in action (KIA); secondary objectives included: reporting mortality at key North Atlantic Treaty Organisation timelines (0, 10, 60, 120 min), comparison of temporal lethality for different anatomical injuries and analysing trends in the case fatality rate (CFR).

RESULTS

2413 UK personnel were injured in Afghanistan from 2004 to 2014; 448 died, with a CFR of 18.6%. 390 (87.1%) of these died prehospital (n=348 KIA, n=42 killed non-enemy action). Complete data were available for n=303 (87.1%) KIA: median Injury Severity Score 75.0 (IQR 55.5-75.0). The predominant mechanisms were improvised explosive device (n=166, 54.8%) and gunshot wound (n=96, 31.7%).In the KIA cohort, the median time to death was 0.0 (IQR 0.0-21.8) min; 173 (57.1%) died immediately (0 min). At 10, 60 and 120 min post injury, 205 (67.7%), 277 (91.4%) and 300 (99.0%) casualties were dead, respectively. Whole body primary injury had the fastest mortality. Overall prehospital CFR improved throughout the period while in-hospital CFR remained constant.

CONCLUSION

Over two-thirds of KIA deaths occurred within 10 min of injury. Improvement in the CFR in Afghanistan was predominantly in the prehospital phase.

UK Defence Medical Services’ support to the development of a multiagency major incident plan in South Sudan

UK Defence Medical Services personnel deployed in support of the United Nations Mission in South Sudan as part of Operation TRENTON in 2017–2018. One key contribution was the development of a multiagency major incident plan in collaboration with key stakeholders within the region, including our UN partners, other troop-contributing countries and non-governmental organisations. This paper describes the process and contribution made, with some transferable lessons for future similar operations, such as adaptation of our courses. Major incident management is one of several technical areas ripe for a proactive Defence Healthcare Engagement strategy, seeking to offer capacity building in areas where Defence is rich in expertise that is highly sought after by other sectors.

Civil-military cooperation on operational deployment: the Bentiu State Hospital medical training programme

The United Nations Mission in South Sudan has a mandate to protect civilians and support the delivery of humanitarian assistance. Recognising this during Operation TRENTON, UK staff of the UN level 2 hospital were able to support the people of Bentiu through initiatives to develop local health services with on-the-ground civil–military cooperation. The Bentiu State Hospital Medical Training Programme was developed to train and mentor staff associated with healthcare in Bentiu, to help improve service delivery, support local health services with on-the-ground non-governmental organisation/military coordination and to create a platform to facilitate the sharing of information to support local health services with the overall humanitarian response. It was recognised how important it was to deliver a programme that carefully understood the unique challenging limitations, circumstances and environment. Hence careful tailoring of the programme was essential to ensure that the training was valuable, implementable and durable, long beyond the operational deployment of TRENTON. Despite the logistical and practical complexities, the programme was very positively received, and the training team believed that the development and progress made would build a small part of the future infrastructure of healthcare delivery in the region. Future contingency operations are likely to take place in the resource- limited austere environment. As reflected in this deployed initiative, local health training activity providing key knowledge to build resilience for the current and immediate future is a precious and important defence engagement utility.

Intensive care medicine on military operations in the resource-limited environment: a case series

This paper describes a series of critically ill patients who were cared for at a UK military field hospital during Op TRENTON 4, in support of the United Nations Mission in South Sudan. These cases highlight the potential challenges in managing the critically ill patient during contingency operations that take place in an austere resource-limited environment.

Use of supplemental oxygen in emergency patients: a systematic review and recommendations for military clinical practice

INTRODUCTION

Supplemental oxygen is a key element of emergency treatment algorithms. However, in the operational environment, oxygen supply poses a challenge. The lack of high-quality evidence alongside emerging technologies provides the opportunity to challenge current guidelines. The aim of this review was to appraise the evidence for the administration of oxygen in emergency patients and give recommendations for its use in clinical practice.

METHODS

A critical review of the literature was undertaken to determine the evidence for emergency supplemental oxygen use.

RESULTS

Based on interpretation of the limited available evidence, five key recommendations are made: pulse oximetry should be continuous and initiated as early as possible; oxygen should be available to all trauma and medical patients in the forward operating environment; if peripheral oxygen saturations (SpO₂) are greater than or equal to 92%, supplemental oxygen is not routinely required; if SpO₂ is less than 92%, supplemental oxygen should be titrated to achieve an SpO₂ of greater than 92%; and if flow rates of greater than 5 L/min are required, then urgent evacuation and critical care support should be requested.

CONCLUSION

Oxygen is not universally required for all patients. Current guidelines aim to prevent hypoxia but with potentially conservative limits. Oxygen should be administered to maintain SpO₂ at 92% or above. New areas for research, highlighted in this review, may provide a future approach for oxygen use from point of injury to definitive care.

The impact of emergency department patient-controlled analgesia (PCA) on the incidence of chronic pain following trauma and non-traumatic abdominal pain

The effect of patient-controlled analgesia during the emergency phase of care on the prevalence of persistent pain is unkown. We studied individuals with traumatic injuries or abdominal pain 6 months after hospital admission via the emergency department using an opportunistic observational study design. This was conducted using postal questionnaires that were sent to participants recruited to the multi-centre pain solutions in the emergency setting study. Patients with prior chronic pain states or opioid use were not studied. Questionnaires included the EQ5D, the Brief Pain Inventory and the Hospital Anxiety and Depression scale. Overall, 141 out of 286 (49% 95%CI 44-56%) patients were included in this follow-up study. Participants presenting with trauma were more likely to develop persistent pain than those presenting with abdominal pain, 45 out of 64 (70%) vs. 24 out of 77 (31%); 95%CI 24-54%, p < 0.001. There were no statistically significant associations between persistent pain and analgesic modality during hospital admission, age or sex. Across both abdominal pain and traumatic injury groups, participants with persistent pain had lower EQ5D mobility scores, worse overall health and higher anxiety and depression scores (p < 0.05). In the abdominal pain group, 13 out of 50 (26%) patients using patient-controlled analgesia developed persistent pain vs. 11 out of 27 (41%) of those with usual treatment; 95%CI for difference (control - patient-controlled analgesia) -8 to 39%, p = 0.183. Acute pain scores at the time of hospital admission were higher in participants who developed persistent pain; 95%CI 0.7-23.6, p = 0.039. For traumatic pain, 25 out of 35 (71%) patients given patient-controlled analgesia developed persistent pain vs. 20 out of 29 (69%) patients with usual treatment; 95%CI -30 to 24%, p = 0.830. Persistent pain is common 6 months after hospital admission, particularly following trauma. The study findings suggest that it may be possible to reduce persistent pain (at least in patients with abdominal pain) by delivering better acute pain management. Further research is needed to confirm this hypothesis.

Catastrophic haemorrhage in military major trauma patients: a retrospective database analysis of haemostatic agents used on the battlefield

Objectives

Catastrophic haemorrhage is a leading cause of morbidity and mortality in trauma, in both military and civilian settings. There are numerous studies looking at the effectiveness of different haemostatic agents in the laboratory but few in a clinical setting. This study analyses the use of haemostatic dressings used in patients injured on the battlefield and their association with survival.

Method

A retrospective database review was undertaken using the UK Joint Theatre Trauma Registry from 2003 to 2014, during combat operations in Iraq and Afghanistan. Data included patient demographics, the use of haemostatic dressings, New Injury Severity Score (NISS) and patient outcome.

Results

Of 3792 cases, a haemostatic dressing was applied in 317 (either Celox, Hemcon or Quickclot). When comparing patients who had a haemostatic dressing applied versus no haemostatic agent, there was a 7% improvement in survival. Celox was the only individual haemostatic dressing that was associated with a statistically significant improvement in survival, which was most apparent in the more severely injured (NISS 36–75).

Conclusion

We have shown an association between use of haemostatic agents and improved survival, mostly in those with more severe injuries, which is particularly evident in those administered Celox. This supports the continued use of haemostatic agents as part of initial haemorrhage control for patients injured in conflict and suggests that civilian organisations that may need to deal with patients with similar injury patterns should consider their use and implementation.

Triage and the Modified Physiological Triage Tool-24 (MPTT-24)

Major incidents occur on a regular basis. So far in 2017, England has witnessed five terrorism-related major incidents, resulting in approximately 40 fatalities and 400 injured. Triage is a key principle in the effective management of a major incident and involves prioritising patients on the basis of their clinical acuity. This paper describes the limitations associated with existing methods of primary major incident triage and the process of developing a new and improved triage tool-the Modified Physiological Triage Tool-24 (MPTT-24). Whilst the MPTT-24 is likely to be the optimum physiological method for primary major incident triage, it needs to be accompanied by an appropriate secondary triage process. The existing UK military and civilian secondary triage tool, the Triage Sort, is described, which offers little advantage over primary methods for identifying patients who require life-saving intervention. Further research is required to identify the optimum method of secondary triage.

Major incident triage and the implementation of a new triage tool, the MPTT-24

Introduction

The Modified Physiological Triage Tool (MPTT) is a recently developed primary triage tool and in comparison with existing tools demonstrates the greatest sensitivity at predicting need for life-saving intervention (LSI) within both military and civilian populations. To improve its applicability, we proposed to increase the upper respiratory rate (RR) threshold to 24 breaths per minute (bpm) to produce the MPTT-24. Our aim was to conduct a feasibility analysis of the proposed MPTT-24, comparing its performance with the existing UK Military Sieve.

Method

A retrospective review of the Joint Theatre Trauma Registry (JTTR) and Trauma Audit Research Network (TARN) databases was performed for all adult (>18 years) patients presenting between 2006–2013 (JTTR) and 2014 (TARN). Patients were defined as priority one (P1) if they received one or more LSIs. Using first recorded hospital RR in isolation, sensitivity and specificity of the ≥24 bpm threshold was compared with the existing threshold (≥22 bpm) at predicting P1 status. Patients were then categorised as P1 or not-P1 by the MPTT, MPTT-24 and the UK Military Sieve.

Results

The MPTT and MPTT-24 outperformed existing UK methods of triage with a statistically significant (p<0.001) increase in sensitivity of between 25.5% and 29.5%. In both populations, the MPTT-24 demonstrated an absolute reduction in sensitivity with an increase in specificity when compared with the MPTT. A statistically significant difference was observed between the MPTT and MPTT-24 in the way they categorised TARN and JTTR cases as P1 (p<0.001).

Conclusions

When compared with the existing MPTT, the MPTT-24 allows for a more rapid triage assessment. Both continue to outperform existing methods of primary major incident triage and within the military setting, the slight increase in undertriage is offset by a reduction in overtriage. We recommend that the MPTT-24 be considered as a replacement to the existing UK Military Sieve.

The outcome of patients in traumatic cardiac arrest presenting to deployed military medical treatment facilities: data from the UK Joint Theatre Trauma Registry

Background

The UK military was continuously engaged in armed conflict in Iraq and Afghanistan between 2003 and 2014, resulting in 629 UK fatalities. Traumatic cardiac arrest (TCA) is a precursor to traumatic death, but data on military outcomes are limited. In order to better inform military treatment protocols, the aim of this study was to define the epidemiology of TCA in the military population with a particular focus on survival rates and injury patterns.

Methods

A retrospective database analysis of the UK Joint Theatre Trauma Registry was undertaken. Patients who were transported to a UK deployed hospital between 2003 and 2014 and suffered TCA were included. Those patients injured by asphyxiation, electrocution, burns without other significant trauma and drowning were excluded. Data included mechanism of injury, Injury Severity Score (ISS), Abbreviated Injury Scale (AIS) for each body region and survival to deployed (Role 3) field hospital discharge.

Results

424 TCA patients were identified during the study period; median age was 23 years, with a median ISS of 45. The most common mechanism of injury was explosive (55.7%), followed by gunshot wound (38.9%), road traffic collision (3.5%), crush (1.7%) and fall (0.2%). 45 patients (10.6% (95% CI 8.0% to 13.9%)) survived to deployed (Role 3) hospital discharge. The most prevalent body region with a severe to maximum AIS injury was the head, followed by the lower limbs, thorax and abdomen. Haemorrhage secondary to abdominal and lower limb injury was associated with survival; traumatic brain injury was associated with death.

Conclusions

This study has shown that short-term survival from TCA in a military population is 10.6%. With appropriate and aggressive early management, although unlikely, survival is still potentially possible in military patients who suffer traumatic cardiac arrest.

The cost-effectiveness of patient-controlled analgesia vs. standard care in patients presenting to the Emergency Department in pain, who are subsequently admitted to hospital

The clinical effectiveness of patient-controlled analgesia has been demonstrated in a variety of settings. However, patient-controlled analgesia is rarely utilised in the Emergency Department. The aim of this study was to compare the cost-effectiveness of patient-controlled analgesia vs. standard care in participants admitted to hospital from the Emergency Department with pain due to traumatic injury or non-traumatic abdominal pain. Pain scores were measured hourly for 12 h using a visual analogue scale. Cost-effectiveness was measured as the additional cost per hour in moderate to severe pain avoided by using patient-controlled analgesia rather than standard care (the incremental cost-effectiveness ratio). Sampling variation was estimated using bootstrap methods and the effects of parameter uncertainty explored in a sensitivity analysis. The cost per hour in moderate or severe pain averted was estimated as £24.77 (€29.05, US$30.80) (bootstrap estimated 95%CI £8.72 to £89.17) for participants suffering pain from traumatic injuries and £15.17 (€17.79, US$18.86) (bootstrap estimate 95%CI £9.03 to £46.00) for participants with non-traumatic abdominal pain. Overall costs were higher with patient-controlled analgesia than standard care in both groups: pain from traumatic injuries incurred an additional £18.58 (€21.79 US$23.10) (95%CI £15.81 to £21.35) per 12 h; and non-traumatic abdominal pain an additional £20.18 (€23.67 US$25.09) (95%CI £19.45 to £20.84) per 12 h.

Histological Comparison of Implanted Cadaveric and Porcine Dermal Matrix Grafts

OBJECTIVES: Histological comparison of human-based (AlloDerm) and porcine-based (ENDURAGen) dermal matrices regarding tissue incorporation and neovascularization as potential soft tissue augmentation materials.

STUDY DESIGN: In vivo, rat model.

METHODS: Subcutaneous implantation of 1-mm thick, 1 cm X 1 cm pieces of AlloDerm, ENDURAGen, and meshed ENDURAGen was performed in 24 Sprague Dawley rats. Implant materials were harvested at 4 (n = 12) and 8 weeks (n = 12). Histological quantification of soft tissue ingrowth and microvascular density was performed following hematoxylin-eosin staining and CD34 immunohistochemistry, respectively.

RESULTS: AlloDerm showed significantly greater soft tissue in-growth and microvascular density compared with both ENDURAGen and meshed ENDURAGen at 4 and 8 weeks ( P < 0.001).

CONCLUSIONS: Although these results may differ in human host tissues, AlloDerm seems to be a more suitable dermal matrix implant than ENDURAGen for cases in which tissue incorporation and neovascularization are sought for the optimal outcome based on this animal model.

The changing face of major trauma in the UK

Aim

Major trauma (MT) has traditionally been viewed as a disease of young men caused by high-energy transfer mechanisms of injury, which has been reflected in the configuration of MT services. With ageing populations in Western societies, it is anticipated that the elderly will comprise an increasing proportion of the MT workload. The aim of this study was to describe changes in the demographics of MT in a developed Western health system over the last 20 years.

Methods

The Trauma Audit Research Network (TARN) database was interrogated to identify all cases of MT (injury severity score >15) between 1990 and the end of 2013. Age at presentation, gender, mechanism of injury and use of CT were recorded. For convenience, cases were categorised by age groups of 25 years and by common mechanisms of injury. Longitudinal changes each year were recorded.

Results

Profound changes in the demographics of recorded MT were observed. In 1990, the mean age of MT patients within the TARN database was 36.1, the largest age group suffering MT was 0–24 years (39.3%), the most common causative mechanism was road traffic collision (59.1%), 72.7% were male and 33.6% underwent CT. By 2013, mean age had increased to 53.8 years, the single largest age group was 25–50 years (27.1%), closely followed by those >75 years (26.9%), the most common mechanism was low falls (39.1%), 68.3% were male and 86.8% underwent CT.

Conclusions

This study suggests that the MT population identified in the UK is becoming more elderly, and the predominant mechanism that precipitates MT is a fall from <2 m. Significant improvements in outcomes from MT may be expected if services targeting the specific needs of the elderly are developed within MT centres.

Challenging the dogma of traumatic cardiac arrest management: a military perspective

Attempts to resuscitate patients in traumatic cardiac arrest (TCA) have, in the past, been viewed as futile. However, reported outcomes from TCA in the past five years, particularly from military series, are improving. The pathophysiology of TCA is different to medical causes of cardiac arrest, and therefore, treatment priorities may also need to be different. This article reviews recent literature describing the pathophysiology of TCA and describes how the military has challenged the assumption that outcome is universally poor in these patients.

Complotype affects the extent of down-regulation by Factor I of the C3b feedback cycle in vitro

Sera from a large panel of normal subjects were typed for three common polymorphisms, one in C3 (R102G) and two in Factor H (V62I and Y402H), that influence predisposition to age-related macular degeneration and to some forms of kidney disease. Three groups of sera were tested; those that were homozygous for the three risk alleles; those that were heterozygous for all three; and those homozygous for the low-risk alleles. These groups vary in their response to the addition of exogenous Factor I when the alternative complement pathway is activated by zymosan. Both the reduction in the maximum amount of iC3b formed and the rate at which the iC3b is converted to C3dg are affected. For both reactions the at-risk complotype requires higher doses of Factor I to produce similar down-regulation. Because iC3b reacting with the complement receptor CR3 is a major mechanism by which complement activation gives rise to inflammation, the breakdown of iC3b to C3dg can be seen to have major significance for reducing complement-induced inflammation. These findings demonstrate for the first time that sera from subjects with different complement alleles behave as predicted in an in-vitro assay of the down-regulation of the alternative complement pathway by increasing the concentration of Factor I. These results support the hypothesis that exogenous Factor I may be a valuable therapeutic aid for down-regulating hyperactivity of the C3b feedback cycle, thereby providing a treatment for age-related macular degeneration and other inflammatory diseases of later life.

Paediatric traumatic cardiac arrest: data from the Joint Theatre Trauma Registry

BACKGROUND

Traumatic cardiac arrest (TCA) in children is associated with a low probability of survival and poor neurological outcome in survivors. Since 2003, over 600 seriously injured local national children have been treated at deployed UK military medical treatment facilities during the Iraq and Afghanistan conflicts. A number of these were in cardiac arrest after sustaining traumatic injuries. This study defined outcomes from paediatric TCA in this cohort.

METHODS

A retrospective database review was undertaken using the UK Joint Theatre Trauma Registry. This includes UK military, coalition military, civilians and local security forces personnel who prompted trauma team activation. All children in this series were local nationals. Patients aged less than 18 years who presented between January 2003 and April 2014, and who underwent cardiopulmonary resuscitation, were included.

RESULTS

27 children with TCA were included. Four children survived to discharge from the medical treatment facility (14.8%), though limited data are available regarding the long-term neurological outcome in these patients.

CONCLUSIONS

This study demonstrates that the outcomes for paediatric TCA in our military field hospitals were similar to other paediatric civilian and adult military studies, despite patients being injured by severe blast injuries. Further work is needed to define the optimal management of paediatric TCA.

The use of impedance threshold devices in spontaneously breathing, hypotensive trauma patients

Impedance threshold devices are a novel therapeutic option to increase blood pressure in the spontaneously breathing, hypotensive, trauma patient. They have multiple potential mechanisms of action. The most important is their ability to induce a more negative intrathoracic pressure during inspiration. They achieve this by the presence of a series of valves. These valves only open once the patient has generated a more negative intrathoracic pressure than is normally required for inspiration to occur. This negative intrathoracic pressure is thought to increase venous return and therefore cardiac output and subsequently blood pressure. This narrative review examines the evidence pertaining to the use of these devices in spontaneously breathing, hypotensive, trauma patients. While the literature supports the ability of these devices to increase systolic blood pressure in both animal and human models of hypotension, and more recently in patients with true pathological hypotension, potential flaws are discussed, and several key questions that have not been addressed by studies to date are highlighted. Notwithstanding these problems, impedance threshold devices may have a role in hypotensive trauma patients, particularly during the pre-hospital phase of care when available resources limit treatment options. Further work is required to prove both their clinical effectiveness and safety.

Preparation of the trauma response in a UK emergency department

An immediate, effective team response is needed in order to properly cater to the needs of trauma patients. This paper aims to review some of the strategies that can be implemented in Emergency Departments to reduce errors and improve decision-making in major trauma. It focuses on the phase prior to the patient’s arrival, and in the first few minutes afterwards – as there is evidence that an organised response at this point creates the ideal conditions for all subsequent activity, such as transfer of the patient for further imaging and the requirement for emergency surgery.

Action Stations! 100 years of trauma care on maritime and amphibious operations in the Royal Navy

Over the past century trauma care within the Royal Navy (RN) has evolved; wartime experiences and military medical research have combined to allow significant improvement in the care of casualties. This article describes the key maritime and amphibious operations that have seen the Royal Navy Medical Service (RNMS) deliver high levels of support to wherever the Naval Service has deployed in the last 100 years. Key advancements in which progress has led to improved outcomes for injured personnel are highlighted--the control and treatment of blood loss, wound care, and the prevention and management of organ failure with optimal resuscitation. Historians often point out how slowly military medicine progressed for the first few thousand years of its recorded history, and how quickly it has progressed in the last century. This reflective article will show how the RNMS has been an integral part of that story, and how the lessons learnt by our predecessors have shaped our modern day doctrine surrounding trauma care.

Glasgow Coma Scale is unreliable for the prediction of severe head injury in elderly trauma patients

OBJECTIVES AND BACKGROUND

Elderly patients comprise an ever-increasing proportion of major trauma patients. The presenting GCS in elderly patients with traumatic brain injury (TBI) may not reflect the severity of injury as accurately as it does in the younger patient population. However, GCS is often used as part of the decision tool to define the population transferred directly to a major trauma centre. The aim of this study was to explore the relationship between age and presenting GCS in patients with isolated TBI.

METHODS

A retrospective database review was undertaken using the Trauma Audit and Research Network database. All patients presenting to Derriford Hospital, Plymouth, between 1 January 2009 and 31 May 2014 with isolated TBI were included. Demographic, mechanistic, physiological, resource use and outcome data were collected. Abbreviated injury scale (AIS) was recorded for all patients. Patients were categorised into those older and younger than 65 years on presentation. Distribution of GCS, categorised into severe (GCS 3-8), moderate (GCS 9-12) and mild TBI (13-15), was compared between the age groups. Median GCS at each AIS level was also compared.

RESULTS

The distribution of GCS differed between young and old patients with TBI (22.1% vs 9.8% had a GCS 3-8, respectively) despite a higher burden of anatomical injury in the elderly group. Presenting GCS was higher in the elderly at each level of AIS. The difference was more apparent in the presence of more severe injury (AIS 5).

CONCLUSIONS

Elderly patients who have sustained isolated severe TBI may present with a higher GCS than younger patients. Triage tools using GCS may need to be modified and validated for use in elderly patients with TBI.

Rapid sequence induction of anaesthesia via the intraosseous route: a prospective observational study

BACKGROUND

Intraosseous (IO) drug infusion has been reported to have similar pharmacokinetics to intravenous (IV) infusion. In military and civilian trauma, the IO route is often used to obtain rapid and reliable parenteral access for drug administration. Only a few case reports have described the use of IO infusion to administer drugs for rapid sequence induction of anaesthesia (RSI).

OBJECTIVE

We aimed to assess the feasibility of the administration of RSI drugs via an IO catheter in a prospective observational study.

METHODS

A prospective observational study was undertaken at a combat hospital in Afghanistan. A validated data form was used to record the use of IO drugs for RSI by the prehospital, physician-led Medical Emergency Response Team (MERT), and by inhospital physicians. Data were captured between January and May 2012 by interview with MERT physicians and inhospital physicians directly after RSI. The primary outcome measure was the success rate of first-pass intubation with direct laryngoscopy.

RESULTS

34 trauma patients (29 MERT and 5 inhospital) underwent RSI with IO drug administration. The median age was 24 years and median injury severity score 25; all were male. The predominant mechanism of injury was blast (n=24), followed by penetrating (n=6), blunt (n=3) and burn (n=1). First-pass intubation success rate was 97% (95% CI 91% to 100%). A Cormack-Lehane grade 1 view, by direct laryngoscopy, was obtained at first look in 91% (95% CI 81% to 100%) of patients.

CONCLUSIONS

In this prospective, observational study, IO drug administration was successfully used for trauma RSI, with a comparable first pass intubation success than published studies describing the IV route.

TRIAL REGISTRATION NUMBER

RCDM/Res/Audit/1036/12/0162.

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.

An evaluation of the use of a two-tiered trauma team activation system in a UK major trauma centre

OBJECTIVES AND BACKGROUND

Appropriate activation of multidisciplinary trauma teams improves outcome for severely injured patients but can disrupt normal service in the rest of the hospital. Derriford Hospital uses a two-tiered trauma team activation system. The emergency department trauma team (EDTT) is activated in response to a significant traumatic mechanism; the hospital trauma team (HTT) is activated when this mechanism coexists with physiological abnormality or specific anatomical injury. The aim of this study was to compare characteristics, process measures and outcomes between patients treated by EDTTs or HTTs to evaluate the approach in a UK setting.

METHODS

A retrospective database review was performed using Trauma Audit Research Network (TARN) and the local source trauma database. Patients who activated a trauma team between 1 April and 30 September 2012 were included. Patients were categorised according to the type of trauma team activated. Data included time to X-rays, time to CT, time to intubation, numbers discharged from ED, intensive care unit admission, injury severity score and mortality.

RESULTS

During the study period, 456 patients activated a trauma team with 358 EDTT and 98 HTT activations. Patients seen by the ED team were significantly less likely to have severe injury or require hospital admission, intubation, emergency operation or blood transfusion. Differences in time taken to key investigations were statistically but not clinically significant.

CONCLUSIONS

A two-tiered trauma team activation system is an efficient and cost-effective way of dealing with trauma patients presenting to a major trauma centre in the UK.

Necrotizing fasciitis of the ear: an unusual case

We describe a rare case of necrotizing fasciitis of the ear in an otherwise generally healthy 39-year-old man. The ear is rarely involved in this often-fatal disease. The diagnosis was suspected on the basis of clinical examination and confirmed by computed tomography and pathology of a biopsy specimen, which revealed subcutaneous gas formation and dermal infiltration of inflammatory cells, respectively. The patient was promptly treated with surgical debridement, intravenous antibiotics, and hyperbaric oxygen. He recovered well and subsequently underwent otoplastic reconstruction with very satisfactory results. By documenting this case, we aim to heighten awareness of necrotizing fasciitis of the head and neck in an effort to improve survival rates.

Optimising the management of severe Traumatic Brain Injury in the military maritime environment

Severe Traumatic Brain Injury (sTBI) is a devastating cause of morbidity and mortality, especially among those aged less than 45 years. Advances in clinical practice continue to focus on preventing primary injury through developing ballistic head and eye protection, and through minimising secondary brain injury (secondary prevention). Managing sTBI is challenging in well-developed, well-resourced healthcare systems. Achieving management aims in the military maritime environment poses even greater challenges. Strategies for the management of sTBI in the maritime environment should be in keeping with current best evidence. Provision of specialist interventions for sTBI in military maritime environments may require alternative approaches matched to the skills of the staff and environmental restrictions.

Intraosseous access in the military operational setting

INTRODUCTION

In an operational military environment, circulatory access can prove difficult for a variety of reasons including profound hypovolaemia, and limited first responder experience. With many injuries that cause catastrophic haemorrhage, such as traumatic limb amputations, circulatory access is needed as quickly as possible. Since 2006, the Defence Medical Services have been using the EZ-IO and FAST1 devices as a means of obtaining circulatory access.

METHODS

A prospective observational study was conducted between March and July 2011 at the Emergency Department, Camp Bastion, Afghanistan. All patients with an intraosseous device had data recorded that included if the device successfully flushed (functionality) and if any problems were encountered.

RESULTS

117 patients presented with a total of 195 devices: 149 were EZ-IO (76%) and 46 were FAST1 (24%). Functionality was recorded for 111 (57%), with 17 failing to function, yielding an overall success rate of 84.7%. Device failure was observed to be more prevalent in the humerus; inability to flush the device was the leading cause, followed by mechanical failure. There were 2 complications, device breaking on removal being the reason for both.

CONCLUSIONS

The devices in the study were tested for a period of time following insertion (median 32 minutes), and still the success rates mirror those found in the literature. Observed differences between sites were not found to be significant with confidence intervals overlapping. Further work is proposed to investigate the long-term complications of intraosseous devices.

Salt or sugar for your injured brain? A meta-analysis of randomised controlled trials of mannitol versus hypertonic sodium solutions to manage raised intracranial pressure in traumatic brain injury

BACKGROUND

Rising intracranial pressure (ICP) is a poor prognostic indicator in traumatic brain injury (TBI). Both mannitol and hypertonic sodium solutions are used to treat raised ICP in patients with TBI.

OBJECTIVE

This meta-analysis compares the use of mannitol versus hypertonic sodium solutions for ICP control in patients with TBI.

DATA SOURCES AND STUDY ELIGIBILITY

Randomised clinical trials in adults with TBI and evidence of raised ICP, which compare the effect on ICP of hypertonic sodium solutions and mannitol.

METHODS

The primary outcome measure is the pooled mean reduction in ICP. Studies were combined using a Forest plot.

RESULTS

Six studies were included, comprising 171 patients (599 episodes of raised ICP). The weighted mean difference in ICP reduction, using hypertonic sodium solutions compared with mannitol, was 1.39 mm Hg (95% CI -0.74 to 3.53).

LIMITATIONS

Methodological differences between studies limit the conclusions of this meta-analysis.

CONCLUSIONS

The evidence shows that both agents effectively lower ICP. There is a trend favouring the use of hypertonic sodium solutions in patients with TBI.

Is a two-tier trauma team activation system the most effective way to manage trauma in the UK?

This review describes the evidence exploring the use of a two-tier trauma team activation system, reviewing the background, history, data available and potential benefits and downsides. The current evidence suggests that a two-tier system may be a lean, cost-effective system, focussed on patient outcome, which could be implemented throughout the UK. Despite its current use in some hospitals, there is limited data from similar systems supporting this in a UK setting. Specific activation criteria need to be validated to ensure appropriate activation of trauma teams, ensuring optimal patient outcome and ensuring best practice.