Electrophysiology and 3D-imaging reveal properties of human intracardiac neurons and increased excitability with atrial fibrillation.

Altered autonomic input to the heart plays a major role in atrial fibrillation (AF). Autonomic neurons termed ganglionated plexi (GP) are clustered on the heart surface to provide the last point of neural control of cardiac function. To date the properties of GP neurons in humans are unknown. Here we have addressed this knowledge gap in human GP neuron structure and physiology in patients with and without AF. Human right atrial GP neurons embedded in epicardial adipose tissue were excised during open heart surgery performed on both non-AF and AF patients and then characterised physiologically by whole cell patch clamp techniques. Structural analysis was also performed after fixation at both the single cell and at the entire GP levels via three-dimensional confocal imaging. Human GP neurons were found to exhibit unique properties and structural complexity with branched neurite outgrowth. Significant differences in excitability were revealed between AF and non-AF GP neurons as measured by lower current to induce action potential firing, a reduced occurrence of low action potential firing rates, decreased accommodation and increased synaptic density. Visualisation of entire GPs showed almost all neurons are cholinergic with a small proportion of noradrenergic and dual phenotype neurons. Phenotypic distribution differences occurred with AF including decreased cholinergic and dual phenotype neurons, and increased noradrenergic neurons. These data show both functional and structural differences occur between GP neurons from patients with and without AF, highlighting that cellular plasticity occurs in neural input to the heart that could alter autonomic influence on atrial function. KEY POINTS: The autonomic nervous system plays a critical role in regulating heart rhythm and the initiation of AF; however, the structural and functional properties of human autonomic neurons in the autonomic ganglionated plexi (GP) remain unknown. Here we perform the first whole cell patch clamp electrophysiological and large tissue confocal imaging analysis of these neurons from patients with and without AF. Our data show human GP neurons are functionally and structurally complex. Measurements of action potential kinetics show higher excitability in GP neurons from AF patients as measured by lower current to induce action potential firing, reduced low firing action potential rates, and decreased action potential accommodation. Confocal imaging shows increased synaptic density and noradrenergic phenotypes in patients with AF. Both functional and structural differences occur in GP neurons from patients with AF that could alter autonomic influence on atrial rhythm.

Intra-Areal Visual Topography in Primate Brains Mapped with Probabilistic Tractography of Diffusion-Weighted Imaging.

Noninvasive diffusion-weighted magnetic resonance imaging (dMRI) can be used to map the neural connectivity between distinct areas in the intact brain, but the standard resolution achieved fundamentally limits the sensitivity of such maps. We investigated the sensitivity and specificity of high-resolution postmortem dMRI and probabilistic tractography in rhesus macaque brains to produce retinotopic maps of the lateral geniculate nucleus (LGN) and extrastriate cortical visual area V5/MT based on their topographic connections with the previously established functional retinotopic map of primary visual cortex (V1). We also replicated the differential connectivity of magnocellular and parvocellular LGN compartments with V1 across visual field positions. Predicted topographic maps based on dMRI data largely matched the established retinotopy of both LGN and V5/MT. Furthermore, tractography based on in vivo dMRI data from the same macaque brains acquired at standard field strength (3T) yielded comparable topographic maps in many cases. We conclude that tractography based on dMRI is sensitive enough to reveal the intrinsic organization of ordered connections between topographically organized neural structures and their resultant functional organization.

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.

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.

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.

Individual Differences in the Alignment of Structural and Functional Markers of the V5/MT Complex in Primates.

Extrastriate visual area V5/MT in primates is defined both structurally by myeloarchitecture and functionally by distinct responses to visual motion. Myelination is directly identifiable from postmortem histology but also indirectly by image contrast with structural magnetic resonance imaging (sMRI). First, we compared the identification of V5/MT using both sMRI and histology in Rhesus macaques. A section-by-section comparison of histological slices with in vivo and postmortem sMRI for the same block of cortical tissue showed precise correspondence in localizing heavy myelination for V5/MT and neighboring MST. Thus, sMRI in macaques accurately locates histologically defined myelin within areas known to be motion selective. Second, we investigated the functionally homologous human motion complex (hMT+) using high-resolution in vivo imaging. Humans showed considerable intersubject variability in hMT+ location, when defined with myelin-weighted sMRI signals to reveal structure. When comparing sMRI markers to functional MRI in response to moving stimuli, a region of high myelin signal was generally located within the hMT+ complex. However, there were considerable differences in the alignment of structural and functional markers between individuals. Our results suggest that variation in area identification for hMT+ based on structural and functional markers reflects individual differences in human regional brain architecture.

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.

The prospective validation of the Modified Physiological Triage Tool (MPTT): an evidence-based approach to major incident triage.

INTRODUCTION: Triage is a key principle in the effective management of major incidents. There is limited evidence to support existing triage tools, with a number of studies demonstrating poor performance at predicting the need for a life-saving intervention. The Modified Physiological Triage Tool (MPTT) is a novel triage tool derived using logistic regression, and in retrospective data sets has shown optimum performance at predicting the need for life-saving intervention. MATERIALS AND METHODS: Physiological data and interventions were prospectively collected for consecutive adult patients with trauma (>18 years) presenting to the emergency department at Camp Bastion, Afghanistan, between March and September 2011. Patients were considered priority 1 (P1) if they received one or more interventions from a previously defined list. Patients were triaged using existing triage tools and the MPTT. Performance was measured using sensitivity and specificity, and a McNemar test with Bonferroni calculation was applied for tools with similar performance. RESULTS: The study population comprised 357 patients, of whom 214 (59.9%) were classed as P1. The MPTT (sensitivity: 83.6%, 95% CI 78.0% to 88.3%; specificity: 51.0%, 95% CI 42.6% to 59.5%) outperformed all existing triage tools at predicting the need for life-saving intervention, with a 19.6% absolute reduction in undertriage compared with the existing Military Sieve. The improvement in undertriage comes at the expense of overtriage; rates of overtriage were 11.6% higher with the MPTT than the Military Sieve. Using a McNemar test, a statistically significant (p<0.001) improvement in overall performance was demonstrated, supporting the use of the MPTT over the Military Sieve. DISCUSSION AND CONCLUSIONS: The MPTT outperforms all existing triage tools at predicting the need for life-saving intervention, with the lowest rates of undertriage while maintaining acceptable levels of overtriage. Having now been validated on both military and civilian cohorts, we recommend that the major incident community consider adopting the MPTT for the purposes of primary triage.

A pilot study to evaluate the utility of live training (LIVEX) in the operational preparedness of UK military trauma teams.

BACKGROUND: With the end of UK military operations in Iraq and Afghanistan, it is essential that peacetime training of Defence Medical Services (DMS) trauma teams ensures appropriate future preparedness. A new model of pre-deployment training involves placement of formed military trauma teams into civilian trauma centres. This study evaluates the benefit of 'live training during an exercise period' (LIVEX) for DMS trauma teams. METHODS: A cross-sectional questionnaire-based survey of participants was conducted. Quantitative data were collected prior to the start and on the final day. Written reports were collected from the coordinators. Thematic analysis was used to identify emergent themes in a supplementary, qualitative analysis. RESULTS: Each team comprised 13 personnel and results should be interpreted with knowledge of this small sample size. The response rate for both the pre-LIVEX and post-LIVEX questionnaire was 100%. By the end of the week, 89% of participants (n=23) stated LIVEX was an 'appropriate or very appropriate' way of preparing for an operational role compared with 40% (n=9) before the exercise (p<0.01). However, completing LIVEX made no difference to participants' personal perception of their own operational preparedness. Thematic analysis suggested greater training benefit for more junior members of the team; from Regulars and Reservists training together; and from two-way exchange of information between DMS and National Health Service medical staffs. CONCLUSIONS: Completing LIVEX made no statistically significant difference to participants' personal perception of their own operational preparedness, but the perception of LIVEX as an appropriate training platform improved significantly after conducting the training exercise.

Older patients with traumatic brain injury present with a higher GCS score than younger patients for a given severity of injury.

INTRODUCTION: Recent evidence suggests that presenting GCS may be higher in older rather than younger patients for an equivalent anatomical severity of traumatic brain injury (TBI). The aim of this study was to confirm these observations using a national trauma database and to test explanatory hypotheses. METHODS: The Trauma Audit Research Network database was interrogated to identify all adult cases of severe isolated TBI from 1988 to 2013. Cases were categorised by age into those under 65 years and those 65 years and older. Median presenting GCS was compared between the groups at abbreviated injury score (AIS) level (3, 4 and 5). Comparisons were repeated for subgroups defined by mechanism of injury and type of isolated intracranial injury. RESULTS: 25 082 patients with isolated TBI met the inclusion criteria, 10 936 in the older group and 14 146 in the younger group. Median or distribution of presenting GCS differed between groups at each AIS level. AIS 3: 14 (11-15) vs 15 (13-15), AIS 4: 14 (9-15) vs 14 (13-15), AIS 5: 9 (4-14) vs 14 (5-15) all p<0.001. Similar differences between the groups were observed across all mechanisms of injury and types of isolated intracranial injury. We detected no influence of gender on results. CONCLUSIONS: For an equivalent severity of intracranial injury, presenting GCS is higher in older patients than in the young. This observation is unlikely to be explained by differences in mechanism of injury or types of intracranial injury between the two groups.

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 success of battlefield surgical airway insertion in severely injured military patients: a UK perspective.

BACKGROUND: The insertion of a surgical airway in the presence of severe airway compromise is an uncommon occurrence in everyday civilian practice. In conflict, the requirement for insertion of a surgical airway is more common. Recent military operations in Afghanistan resulted in large numbers of severely injured patients, and a significant proportion required definitive airway management through the insertion of a surgical airway. OBJECTIVE: To examine the procedural success and survival rate to discharge from a military hospital over an 8-year period. METHODS: A retrospective database and chart review was conducted, using the UK Joint Theatre Trauma Registry and the Central Health Records Library. Patients who underwent surgical airway insertion by UK medical personnel from 2006 to 2014 were included. Procedural success, demographics, Injury Severity Score, practitioner experience and patient survival data were collected. Descriptive statistics were used for data comparison, and statistical significance was defined as p<0.05. RESULTS: 86 patients met the inclusion criterion and were included in the final analysis. The mean patient age was 25 years, (SD 5), with a median ISS of 62.5 (IQR 42). 79 (92%) of all surgical airways were successfully inserted. 7 (8%) were either inserted incorrectly or failed to perform adequately. 80 (93%) of these procedures were performed either by combat medical technicians or General Duties Medical Officers (GDMOs) at the point of wounding or Role 1. 6 (7%) were performed by the Medical Emergency Response Team. 21 (24%) patients survived to hospital discharge. DISCUSSION: Surgical airways can be successfully performed in the most hostile of environments with high success rates by combat medical technicians and GDMOs. These results compare favourably with US military data published from the same conflict.

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.

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.

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.

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.

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.

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.

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.