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Background: Blood transfusion for bleeding trauma patients is a promising pre-hospital intervention with potential to improve outcomes. However, it is not yet clear which patients may benefit from pre-hospital transfusions. The aim of this study was to enhance our understanding of how experienced pre-hospital clinicians make decisions regarding patient blood loss and the need for transfusion, and explore the factors that influence clinical decision-making., Methods: Pre-hospital physicians, from two air ambulance sites in the south of England, were interviewed between December 2018 and January 2019. Participants were involved in teaching or publishing on the management of bleeding trauma patients and had at least 5 years of continuous and contemporary practice at consultant level. Interviews were semi-structured and explored how decisions were made and what made decisions difficult. A qualitative description approach was used with inductive thematic analysis to identify themes and subthemes related to blood transfusion decision-making in trauma., Results: Ten pre-hospital physicians were interviewed and three themes were identified: recognition-primed analysis , uncertainty and imperfect decision analysis . The first theme describes how participants make decisions using selected cues, incorporating their experience and are influenced by external rules and group expectations. What made decisions difficult for the participants was encapsulated in the uncertainty theme. Uncertainty emerged regarding the patient's true underlying physiological state and the treatment effect of blood transfusion. The last theme focuses on the issues with decision-making itself. Participants demonstrated lapses in decision awareness, often incomplete decision evaluation and described challenges to effective learning due to incomplete patient outcome information., Conclusion: Pre-hospital clinicians make decisions about bleeding and transfusion which are recognition-primed and incorporate significant uncertainty. Decisions are influenced by experience and are subject to bias. Improved understanding of the decision-making processes provides a theoretical perspective of how decisions might be supported in the future., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Military surgeons have gained familiarity and experience with mass casualty events (MCEs) as a matter of routine over the course of the last two conflicts in Afghanistan and Iraq. Over the same period of time, civilian surgeons have increasingly faced complex MCEs on the home front. Our objective is to summarize and adapt these combat surgery lessons to enhance civilian surgeon preparedness for complex MCEs on the home front. The authors describe the unique lessons learned from combat surgery over the course of the wars in Afghanistan and Iraq and adapt these lessons to enhance civilian surgical readiness for a MCE on the home front. Military Damage Control Surgery (mDCS) combines the established concept of clinical DCS (cDCS) with key combat situational awareness factors that enable surgeons to optimally care for multiple, complex patients, from multiple simultaneous events, with limited resources. These additional considerations involve the surgeon's role of care within the deployed trauma system and the battlefield effects. The proposed new concept of mass casualty DCS (mcDCS) similarly combines cDCS decisions with key factors of situational awareness for civilian surgeons faced with complex MCEs to optimize outcomes. The additional considerations for a civilian MCE include the surgeon's role of care within the regional trauma system and the incident effects. Adapting institutionalized lessons from combat surgery to civilian surgical colleagues will enhance national preparedness for complex MCEs on the home front.

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., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: Lower extremity vascular trauma (LEVT) is a major cause of amputation. A clear understanding of prognostic factors for amputation is important to inform surgical decision-making, patient counselling and risk stratification. The aim was to develop an understanding of prognostic factors for amputation following surgical repair of LEVT., Methods: A systematic review was conducted to identify potential prognostic factors. Bayesian meta-analysis was used to calculate an absolute (pooled proportion) and relative (pooled odds ratio, OR) measure of the amputation risk for each factor., Results: Forty-five studies, totalling 3187 discrete LEVT repairs, were included. The overall amputation rate was 10·0 (95 per cent credible interval 7·4 to 13·1) per cent. Significant prognostic factors for secondary amputation included: associated major soft tissue injury (26 versus 8 per cent for no soft tissue injury; OR 5·80), compartment syndrome (28 versus 6 per cent; OR 5·11), multiple arterial injuries (18 versus 9 per cent; OR 4·85), duration of ischaemia exceeding 6 h (24 versus 5 per cent; OR 4·40), associated fracture (14 versus 2 per cent; OR 4·30), mechanism of injury (blast 19 per cent, blunt 16 per cent, penetrating 5 per cent), anatomical site of injury (iliac 18 per cent, popliteal 14 per cent, tibial 10 per cent, femoral 4 per cent), age over 55 years (16 versus 9 per cent; OR 3·03) and sex (men 7 per cent versus women 8 per cent; OR 0·64). Shock and nerve or venous injuries were not significant prognostic factors for secondary amputation., Conclusion: A significant proportion of patients who undergo lower extremity vascular trauma repair will require secondary amputation. This meta-analysis describes significant prognostic factors needed to inform surgical judgement, risk assessment and patient counselling., (© 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.)

Complex clinical decisions require the decision maker to evaluate multiple factors that may interact with each other. Many clinical studies, however, report 'univariate' relations between a single factor and outcome. Such univariate statistics are often insufficient to provide useful support for complex clinical decisions even when they are pooled using meta-analysis. More useful decision support could be provided by evidence-based models that take the interaction between factors into account. In this paper, we propose a method of integrating the univariate results of a meta-analysis with a clinical dataset and expert knowledge to construct multivariate Bayesian network (BN) models. The technique reduces the size of the dataset needed to learn the parameters of a model of a given complexity. Supplementing the data with the meta-analysis results avoids the need to either simplify the model - ignoring some complexities of the problem - or to gather more data. The method is illustrated by a clinical case study into the prediction of the viability of severely injured lower extremities. The case study illustrates the advantages of integrating combined evidence into BN development: the BN developed using our method outperformed four different data-driven structure learning methods, and a well-known scoring model (MESS) in this domain., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Background: Venous thromboembolism (VTE) represents a significant preventable cause of hospital mortality. VTE assessment and prophylaxis rates are key patient safety and quality of care indicators. The aim of this study was to audit low molecular weight heparin (LMWH) and graduated elasticated compression stockings (GECS) prescriptions compared with the current Clinical Guidelines for Operations., Methods: Complete audit loop in the Role 3 Hospital, Camp Bastion, Afghanistan. A multifaceted intervention programme incorporating physician and nurse education and pre-printed medication charts was introduced to improve VTE assessment and prophylaxis rates., Results: Only 111/301 (36.9%) of patients in the pre-intervention cohort had a VTE risk assessment performed; this improved to 142/155 (91.6%, p<0.0001) post-intervention. A total of 57/88 (64.8%) patients prescribed LMWH pre-intervention had a documented assessment of bleeding risk performed; this rose to 65/66 (98.5%, p=0.0003) post-intervention. In pre-intervention, only 63/213 (29.6%) patients had a documented reassessment of VTE and bleeding risk at 24 h; reassessment rates rose to 68.8% (66/96 patients, p<0.0001) post-intervention. Of those patients at risk of VTE without ongoing bleeding risk, 62/96 (64.6%) had LMWH prescribed pre-intervention; this rose to 57/62 (91.9%) post-intervention (p<0.0001). Inappropriate LMWH prescription rates fell from 26/190 (13.7%) to 4/85 (4.7%, p=0.035) post-intervention. In those patients in whom GECS were not contraindicated, prescription rates rose from 23/95 (24.2%) to 42/62 (67.7%, p<0.0001) post-intervention., Conclusions: Inclusion of pre-printed LMWH/GECS prescriptions and risk assessment stickers in the mediction chart significantly improved rates of VTE risk assessment and prophylaxis. These easily reproducible and low-cost interventions could improve patient safety on deployment., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Unlabelled: Recent conflicts have led significant advancements in casualty care. Facilities serving combat wounded operate in challenging environments. Our purpose is to describe the multidisciplinary resuscitation algorithm utilized at a United Kingdom-led, Role 3 multinational treatment facility in Afghanistan focusing on injury severity and in-hospital mortality., Methods: Data were extracted from our prospectively collected trauma registry on military members wounded in action., Results: From November 1, 2009 to September 30, 2011, there were 3483 military trauma admissions. Common mechanisms of injury were improvised explosive devices (48%), followed by gunshot wounds (29%). Most patients (83.1%) had an Injury Severity Score (ISS) <15. For patients with complete ISS data, 8.4% had massive transfusion and 6.1% had an initial base deficit >5. Patients admitted with signs of life had a died of wounds rate of 1.8% with an average 1.2 day hospital stay. The mortality rate for patients undergoing massive transfusion was 4.8%, and for patients with a base deficit >5, mortality was 12.3%. Severely injured patients (ISS > 24) had a mortality rate of 16.5%., Conclusion: A systematic, multidisciplinary approach to trauma is associated with low in-hospital mortality. The outcomes in this study serve as a measure for future care in Role 3 facilities., (Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.)

We describe the impact of a targeted performance improvement programme and the associated performance improvement interventions, on mortality rates, error rates and process of care for haemodynamically unstable patients with pelvic fractures. Clinical care and performance improvement data for 185 adult patients with exsanguinating pelvic trauma presenting to a United Kingdom Major Trauma Centre between January 2007 and January 2011 were analysed with univariate and multivariate regression and compared with National data. In total 62 patients (34%) died from their injuries and opportunities for improved care were identified in one third of deaths. Three major interventions were introduced during the study period in response to the findings. These were a massive haemorrhage protocol, a decision-making algorithm and employment of specialist pelvic orthopaedic surgeons. Interventions which improved performance were associated with an annual reduction in mortality (odds ratio 0.64 (95% confidence interval (CI) 0.44 to 0.93), p = 0.02), a reduction in error rates (p = 0.024) and significant improvements in the targeted processes of care. Exsanguinating patients with pelvic trauma are complex to manage and are associated with high mortality rates; implementation of a targeted performance improvement programme achieved sustained improvements in mortality, error rates and trauma care in this group of severely injured patients., (©2014 The British Editorial Society of Bone & Joint Surgery.)

Background: Posttraumatic pulmonary embolism is historically diagnosed after clinical deterioration within the first week after injury. An increasing prevalence of immediate and asymptomatic pulmonary embolism have been reported in civilian and military trauma, termed hereafter as acute peritraumatic pulmonary thrombus (APPT). The objective of this study was to define the frequency of APPT diagnosed by computed tomographic (CT) imaging in wartime casualties. An additional objective was to identify factors, which may be associated with this radiographic finding, Methods: A 1-year retrospective cohort analysis conducted using the US and UK Joint Theater Trauma Registries performed to determine the prevalence of and risk factors for the diagnosis of APPT in casualties admitted to Bastion Hospital, Afghanistan. APPT imaging characteristics were collected, and demographics, injury severity and mechanism, and risk factors were included in the analysis. Logistic regression was used to identify factors independently associated with APPT., Results: APPT was found in 66 (9.3%) of 708 consecutive trauma admissions, which received a CT chest with intravenous contrast as part of their initial evaluation. Diagnosis of APPT at the time of injury was made in 23 patients (3.2%), while thrombus was detected in 43 additional patients (6.1%) at the time of reexamination of CT images. Of the APPTs, 47% (n = 31) were central, 38% (n = 25) were segmental, and 15% (n = 10) were subsegmental. Forty-seven percent (n = 31) had bilateral APPT. Logistic regression found presence of deep venous thrombosis on admission (odds ratio, 5.75; 95% confidence interval, 2.44-13.58; p < 0.0001) and traumatic amputation (odds ratio, 2.53; 95% confidence interval, 1.10-5.85; p = 0.030) to be independently associated with APPT. All APPTs were felt to be incidental and likely would not have required interventions such as anticoagulation or vena caval interruption., Conclusion: This report is the first to characterize acute, peritraumatic pulmonary thrombus in combat injured. Nearly 1 in 10 patients with severe wartime injury has findings of pulmonary thrombus on CT imaging, although many instances require repeat examination of initial images to identify the clot. APPT is a phenomenon of severe injury and associated with deep venous thrombosis and lower-extremity traumatic amputation. Additional study is needed to characterize the natural history of peritraumatic pulmonary thrombus and the indications for anticoagulation or vena cava filter devices.

Background: Hemorrhage following traumatic injury is a leading cause of military and civilian mortality. Noncompressible torso hemorrhage (NCTH) has been identified as particularly lethal, especially in the prehospital setting., Methods: All patients sustaining NCTH between August 2002 and July 2012 were identified from the UK Joint Theatre Trauma Registry. NCTH was defined as injury to a named torso axial vessel, pulmonary injury, solid-organ injury (Grade 4 or greater injury to the liver, kidney, or spleen) or pelvic fracture with ring disruption. Patients with ongoing hemorrhage were identified using either a systolic blood pressure of less than 90 mm Hg or the need for immediate surgical hemorrhage control. Data on injury pattern and location as well as cause of death were analyzed using univariate and multivariate analyses., Results: During 10 years, 296 patients were identified with NCTH, with a mortality of 85.5%. The majority of deaths occurred before hospital admission (n = 222, 75.0%). Of patients admitted to hospital, survivors (n = 43, 14.5%) had a higher median systolic blood pressure (108 [43] vs. 89 [46], p = 0.123) and Glasgow Coma Scale (GCS) (14 [12] vs. 3 [0], p < 0.001) compared with in-hospital deaths (n = 31, 10.5%). Hemorrhage was the more common cause of death (60.1%), followed by central nervous system disruption (30.8%), total body disruption (5.1%), and multiple-organ failure (4.0%). On multivariate analysis, major arterial and pulmonary hilar injury are most lethal with odds ratio (95% confidence interval) of 16.44 (5.50-49.11) and 9.61 (1.06-87.00), respectively., Conclusion: This study demonstrates that the majority of patients sustaining NCTH die before hospital admission, with exsanguination and central nervous system disruption contributing to the bulk cause of death. Major arterial and pulmonary hilar injuries are independent predictors of mortality.

Introduction: Pedal cycling in cities has the potential to deliver significant health and economic benefits for individuals and society. Safety is the main concern for potential cyclists although the statistical risk of death is low. Little is known about the severity of injuries sustained by city cyclists and their outcome., Aim: The aim of this study was to characterise the physiological status and injury profile of cyclists admitted to our urban major trauma centre (MTC)., Methods: Database analysis of cyclist casualties between 2004 and 2009. The physiological parameters examined were admission systolic blood pressure (SBP), admission base deficit and prehospital Glasgow Coma Scale., Results: 265 cyclists required full trauma-team activation. 82% were injured during a collision with a motorised vehicle. The majority (73%) had collided with a car or a heavy goods vehicle (HGV). These casualties formed the cohort for further analysis. Cyclists who collided with an HGV were more severely injured and had a higher mortality rate. Low SBP and high base deficit indicate that haemorrhagic shock is a key feature of HGV casualties., Conclusion: Collision with any vehicle can result in death or serious injury to a cyclist. Injury patterns vary with the type of vehicle involved. HGVs were associated with severe injuries and death as a result of uncontrollable haemorrhage. Awareness of this injury profile may aid prehospital management and expedite transfer to MTC care. Rapid haemorrhage control may salvage some, but not all, of these casualties. The need for continued collision prevention strategies and long-term outcome data collection in trauma patients is highlighted.

Objectives: In the United Kingdom, the epidemiology, management strategies and outcomes from vascular trauma are unknown. The aim of this study was to describe the vascular trauma experience of a British Trauma Centre., Methods: A retrospective observational study of all patients admitted to hospital with traumatic vascular injury between 2005 and 2010., Results: Vascular injuries were present in 256 patients (4.4%) of the 5823 total trauma admissions. Penetrating trauma caused 135 (53%) vascular injuries whilst the remainder resulted from blunt trauma. Compared to penetrating vascular trauma, patients with blunt trauma were more severely injured (median ISS 29 [18-38] vs. ISS 11 [9-17], p < 0.0001), had greater mortality (26% vs. 10%; OR 3.0, 95% CI 1.5-5.9; p < 0.01) and higher limb amputation rates (12% vs. 0%; p < 0.0001). Blunt vascular trauma patients were also twice as likely to require a massive blood transfusion (48% vs. 25%; p = 0.0002) and had a five-fold longer hospital length of stay (median 35 days (15-58) vs. 7 (4-13), p<0.0001) and critical care stay (median 5 days (0-11) vs. 0 (0-2), p < 0.0001) compared to patients with penetrating trauma. Multivariate regression analysis showed that age, ISS, shock and zone of injury were independent predictors of death following vascular trauma., Conclusion: Traumatic vascular injury accounts for 4% of admissions to a British Trauma Centre. These patients are severely injured with high mortality and morbidity, and place a significant demand on hospital resources. Integration of vascular services with regional trauma systems will be an essential part of current efforts to improve trauma care in the UK., (Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Traumatic leg amputation commonly affects young, active people and leads to poor long-term outcomes. The aim of this review was to describe common causes of disability and highlight therapeutic interventions that may optimize outcome after traumatic leg amputation., Methods: A comprehensive search of MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature databases was performed, using the terms 'leg injury', 'amputation' and 'outcome'. Articles reporting outcomes following traumatic leg amputation were included., Results: Studies demonstrated that pain, psychological illness, decreased physical and vocational function, and increased cardiovascular morbidity and mortality were common causes of disability after traumatic leg amputation. The evidence highlights that appropriate preoperative management and operative techniques, in conjunction with suitable rehabilitation and postoperative follow-up, can lead to improved treatment outcome and patient satisfaction., Conclusion: Patients who undergo leg amputation after trauma are at risk of poor long-term physical and mental health. Clinicians involved in their care have many opportunities to improve their outcome using a variety of therapeutic variables. Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd., (Copyright © 2011 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)

Introduction: Definitive laparotomy (DL), with completion of all surgical tasks at first laparotomy has traditionally been the basis of surgical care of severe abdominal trauma. Damage control surgery (DCS) with a goal of physiological normalisation achieved with termination of operation before completion of anatomical reconstruction, has recently found favour in management of civilian trauma. This study aims to characterise the contemporary UK military surgeon's approach to abdominal injury., Patients and Methods: A retrospective analysis was performed on British service personnel who underwent a laparotomy for intestinal injury at UK forward hospitals from November 2003 to March 2008 as identified from the Joint Theatre Trauma Registry. Patient demographics, mechanism and pattern of injury and clinical outcomes were recorded. Surgical procedures at first and subsequent laparotomy were evaluated by an expert panel., Results: 22 patients with intestinal injury underwent laparotomy and survived to be repatriated; all patients subsequently survived to hospital discharge. Mechanism of injury was GSW in seven and blast in 13. At primary laparotomy, as defined by the operating surgeon, 15/22 underwent DL and 7/22 underwent DCS. Mean Injury Severity Score (ISS) was 19 for DL patients compared to 29 for DCS patients (p = 0.021). Of the 15 patients undergoing DL nine had primary repair (suture or resection/ anastomosis), one of which subsequently leaked. Unplanned re-look was required in 4/15 of the DL cases., Conclusion: This review examines the activity of British military surgeons over a time period where damage control laparotomy has been introduced into regular practice. It is performed at a ratio of approximately 1:2 to DL and appears to be reserved, in accordance with military surgical doctrine, for the more severely injured patients. There is a high rate of unplanned relook procedures for DL suggesting DCS may still be underused by military surgeons. Optimal methods of selection and implementation of DCS after battle injury to the abdomen remain unclear.

In this article the process of operating room resuscitation - commonly known as Right Turn Resuscitation (RTR) when conducted in the medical treatment facility at Camp Bastion - is described. The place of RTR within the concepts of damage control resuscitation and surgery is discussed along with activation criteria and protocols. The medical leadership, team roles, advantages and disadvantages are reviewed. Finally, studies describing the impact of RTR and operating room resuscitation are briefly described.

Testing and difficult decision-making is a sine qua non of surgical practice on military operations. Better pre-hospital care protocols, reduced evacuation timelines and increased scrutiny of outcome have rightfully emphasised the requirement of surgeons to "get it right, first time and every time" when treating patients. This article addresses five contentious areas concerning severe torso trauma, with relevant literature summarised by a subject matter expert, in order to produce practical guidance that will assist the newly deployed surgeon in delivering optimal clinical outcomes.

Background: Military injuries to named blood vessels are complex limb- and life-threatening wounds that pose significant difficulties in prehospital and surgical management. The aim of this study was to provide a comprehensive description of the epidemiology, treatment and outcome of vascular injury among service personnel deployed on operations in Afghanistan and Iraq., Methods: Data from the British Joint Theatre Trauma Registry were combined with hospital records to review all cases of vascular trauma in deployed service personnel over a 5-year interval ending in January 2008., Results: Of 1203 injured service personnel, 110 sustained injuries to named vessels; 66 of them died before any surgical intervention. All 25 patients who sustained an injury to a named vessel in the abdomen or thorax died; 24 did not survive to undergo surgery and one casualty in extremis underwent a thoracotomy, but died. Six of 17 patients with cervical vascular injuries survived to surgical intervention; two died after surgery. Of 76 patients with extremity vascular injuries, 37 survived to surgery with one postoperative death. Interventions on 38 limbs included 19 damage control procedures (15 primary amputations, 4 vessel ligations) and 19 definitive limb revascularization procedures (11 interposition vein grafts, 8 direct repairs), four of which failed necessitating three amputations., Conclusion: In operable patients with extremity injury, amputation or ligation is often required for damage control and preservation of life. Favourable limb salvage rates are achievable in casualties able to withstand revascularization. Despite marked progress in contemporary battlefield trauma care, torso vascular injury is usually not amenable to surgical intervention.

There are no published studies directly addressing the issue of what is an acceptable timeline from point of wounding to surgical intervention within the military context. The proximal threshold has previously been determined by personal opinion, tactical, logistic and practical imperatives rather than by clinical demands. The aim of this paper is to review all relevant military and civilian studies where timelines have been quoted and to reach a number of unambiguous consensus statements to state the perceived ideal upper limits from point of wounding to holistic and realistic surgical care in modern war. An injured casualty should be transferred to an appropriate surgeon in an appropriate facility in as short a time from wounding as practical. It is clear that the best trauma surgery is performed in large, well resourced, well-supplied, air-conditioned hospitals. Current advances aimed to stretch timelines from wounding to surgical intervention are exciting and hold potential but remain scientifically unproven and are currently without any firm evidence base. Further critical research is therefore necessary. The effect of pre-hospital haemostatic resuscitation, provided by the enhanced Medical Emergency Response Team (MERTe) on patient outcome and effective timelines is currently unknown and unproven: it does have intuitive medical merit. There is also a very significant moral and morale component. MERTe serves two main functions; reduction in time from point of wounding to advanced / haemostatic resuscitation and provision of in-flight diagnostics. Continuation of in-flight resuscitation then allows physician-led decision making on critically unstable casualties. This allows either an expedited straight move from the HLS direct to the operating theatre or direct transfer to a regional neurosurgical centre. To prevent avoidable death,our unequivocal conclusion is that there must be an upper limit of 2 hours from wounding to surgical intervention (surgical haemorrhage control) for all casualties.

Background: Key performance indicators (KPI) are tools for assessing process and outcome in systems of health care provision and are an essential component in performance improvement. Although KPI have been used in British military trauma for 10 years, they remain poorly defined and are derived from civilian metrics that do not adjust for the realities of field trauma care. Our aim was to modify current trauma KPI to ensure they more faithfully reflect both the military setting and contemporary evidence in order to both aid accurate calibration of the performance of the British Defence Medical Services and act as a driver for performance improvement., Method: A workshop was convened that was attended by senior, experienced doctors and nurses from all disciplines of trauma care in the British military. "Speciality-specific" KPI were developed by interest groups using evidence-based data where available and collective experience where this was lacking. In a final discussion these were streamlined into 60 KPI covering each phase of trauma management., Conclusion: The introduction of these KPI sets a number of important benchmarks by which British military trauma can be measured. As part of a performance improvement programme, these will allow closer monitoring of our performance and assist efforts to develop, train, and resource British military trauma providers.

The objective was to evaluate outcomes of a high-risk patient cohort following endovascular abdominal aortic aneurysm repair (EVAR) treatment not entered into the U.K. endovascular stent-graft aortic aneurysm repair trials (EVAR-1 or -2) because of equipoise absence but where EVAR was judged to be the most appropriate intervention option on compassionate grounds. A single-center retrospective analysis was performed involving all patients undergoing compassionate EVAR treatment during the EVAR-1 and -2 trial period. Over an 8-year period, 34 patients underwent compassionate EVAR procedure. The mean (SD) age was 76 (79) years. The mean (SD) preoperative physiology score (P-POSSUM) was 25 (8.3) with a mean (SD) predicted early mortality of 9.9% (16%). The actual early mortality in our study was 2.9% and morbidity was 35%. There were 8 cases of endoleak: type I (n = 2), type II (n = 5), and type IV (n = 1). Aneurysm-related mortality and all-cause mortality after 8 years were 5.8% and 23.5% respectively. Satisfactory outcome with low mortality (2.9%) and morbidity can be achieved in patients with compassionate indications, where clinicians judge EVAR to be an advantage over open abdominal aortic aneurysm repair. Based on our study, the early mortality (2.9%) in our compassionate EVAR group is comparable to EVAR-1 outcomes (1.7%) and better than EVAR-2 mortality results (9%). EVAR should therefore not be denied to a significant number of high-risk abdominal aortic aneurysm patients who fall between the EVAR-1 and EVAR-2 criteria.

Objective: Graduated compression stockings are a valuable means of thrombo-prophylaxis but it is unclear whether knee-length (KL) or thigh length (TL) stockings are more effective. The aim of this review was to systematically analyse randomised controlled trials that have evaluated stocking length and efficacy of thromboprophylaxis., Method: A systematic review of the literature was undertaken. Clinical trials on hospitalised populations and passengers on long haul flights were selected according to specific criteria and analysed to generate summated data., Results: 14 randomized control trials were analysed. Thirty six of 1568 (2.3%) participants randomised to KL stockings developed a deep venous thrombosis, compared with 79 of 1696 (5%) in the TL control/thigh length group. Substantial heterogeneity was observed amongst trials. KL stockings had a significant effect to reduce the incidence of DVT in long haul flight passengers, odds ration 0.08 (95%CI 0.03-0.22). In hospitalised patients KL stockings did not appear to be far worse than TL stockings, odds ratio 1.01 (95%CI 0.35-2.90). For combined passengers and patients, there was a benefit in favour of KL stockings, weighted odds ratio 0.45 (95% CI 0.30-0.68)., Conclusion: KL graduated stockings can be as effective as TL stockings for the prevention of DVT, whilst offering advantages in terms of patient compliance and cost.

The aim of sodding prosthetic grafts with endothelial cells (EC) is to establish a functioning antithrombogenic monolayer of EC. Application of basement membrane proteins improves EC adherence on ePTFE grafts. Their addition to a biodurable compliant poly(carbonate-urea)urethane graft (CPU) was studied with respect to EC adherence. Preclot, fibronectin, gelatin, and collagen were coated onto CPU. RGD peptide, heparin, and both RGD and heparin were chemically bonded to CPU. Human umbilical vein EC (HUVEC) labeled with 111-Indium oxine were sodded (1.8 x 10(6) EC/cm(2)) onto native and the modified CPU. The grafts were washed after 90 min and EC retention determined. The experiments were repeated six times. EC retention on native CPU was 1.0 +/- 0.2 x 10(5) EC/cm(2). The application of preclot, fibronectin, gelatin, and collagen did not improve EC retention, which was 0.8 +/- 0.1, 0.4 +/- 0.1, 0.3 +/- 0.08, and 0.5 +/- 0.2 x 10(5) EC/cm(2), respectively. Bonding RGD, heparin, and both RGD and heparin significantly improved EC retention to 1.9 +/- 0.6, 1.7 +/- 0.5, and 2.6 +/- 0.6 x 10(5) EC/cm(2), respectively (p < 0.01). Bonding of RGD, heparin, and both RGD and heparin accelerates and enhances EC retention onto CPU. Simple coating of basement membrane proteins confers no advantage over native CPU.

Poly(ester)urethane and poly(ether)urethane vascular grafts fail in vivo because of hydrolytic and oxidative degradative mechanisms. Studies have shown that poly(carbonate)urethanes have enhanced resistance. There is still a need for a viable, nonrigid, small-diameter, synthetic vascular graft. In this study, we sought to confirm this by exposing a novel formulation of compliant poly(carbonate-urea)urethane (CPU) manufactured by an innovative process, resulting in a stress-free. Small-diameter prosthesis, and a conventional poly(ether)urethane Pulse-Tec graft known to readily undergo oxidation in a variety of degradative solutions, and we assessed them for the development of oxidative and hydrolytic degradation, changes in elastic properties, and chemical stability. To simulate the in vivo environment, we used buffered solutions of phospholipase A(2) and cholesterol esterase; solutions of H(2)O(2)/CoCl(2), t-butyl peroxide/CoCl(2) (t-but/CoCl(2)), and glutathione/t-butyl peroxide/CoCl(2) (Glut/t-but/CoCl(2)); and plasma fractions I-IV, which were derived from fresh human plasma centrifuged in poly(ethylene glycol). To act as a negative control, both graft types were incubated in distilled water. Samples of both graft types (100 mm with a 5.0-mm inner diameter) were incubated in these solutions at 37 degrees C for 70 days before environmental scanning electron microscopy, radial tensile strength and quality control, gel permeation chromatography, and in vitro compliance assessments were performed. Oxidative degradation was ascertained from significant changes in molecular weight with respect to a control on all Pulse-Tec grafts treated with t-but/CoCl(2), Glut/t-but/CoCl(2), and plasma fractions I-III. Pulse-Tec grafts exposed to the H(2)O(2)/CoCl(2) mixture had significantly greater compliance than controls incubated in distilled water (p < 0.001 at 50 mmHg). No changes in molecular weight with respect to the control were observed for the CPU samples; only those immersed in t-but/CoCl(2) and Glut/t-but/CoCl(2) showed an 11% increase in molecular weight to 108,000. Only CPU grafts treated with the Glut/t-but/CoCl(2) mixture exhibited significantly greater compliance (p < 0.05 at 50 mmHg). Overall, results from this study indicate that CPU presents a far greater chemical stability than poly(ether)-urethane grafts do., (Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 59: 207-218, 2002)

Background: Compliance mismatch between native artery and prosthetic graft used for infrainguinal bypass is implicated in the aetiology of graft failure. The aim was to quantify the elastic properties of a new compliant poly(carbonate)polyurethane (CPU) vascular graft, and to compare the compliance properties of grafts made from CPU, expanded polytetrafluoroethylene (ePTFE), Dacron and human saphenous vein with that of human muscular artery., Methods: A pulsatile flow phantom was used to perfuse vessel and prosthetic graft segments at physiological pulse pressure and flow. Intraluminal pressure was measured using a Millar Mikro-tip catheter transducer and vessel wall motion was determined with duplex ultrasonography using an echo-locked wall-tracking system. Diametrical compliance and a stiffness index were then calculated for each type of conduit over mean pressures ranging from 30 to 100 mmHg by 10-mmHg increments., Results: The compliance values of CPU and artery (mean over the pressure range) were similar (mean(s.d.) 8.1(0.4) and 8.0(5.9) per cent per mmHg x 10(-2) respectively), although the elastic behaviour of artery was anisotropic unlike CPU, which was isotropic. Dacron and ePTFE grafts had lower compliance values (1.8(1.2) and 1.2(0.3)per cent per mmHg x 10(-2) respectively, averaged over the pressure range). In both these cases, compliance and stiffness differed significantly from that of artery over a mean pressure range of 30-90 mmHg. Human saphenous vein exhibited anisotropic behaviour and, although compliant at low pressure (30 mmHg), was markedly incompliant at higher pressures., Conclusion: Compliant polyurethane grafts offer a greater degree of compliance match than either ePTFE or Dacron.

Objective: The purpose of this study was to further the development of a compliant vascular graft with a preliminary assessment of the elastic properties of the femoropopliteal artery in subjects with and without lower limb peripheral vascular disease., Methods: This prospective controlled study was set in a university department of surgery. Using an ultrasound scan wall tracking system with the simultaneous measurement of brachial blood pressure, measurements of femoropopliteal artery wall motion were undertaken in 11 patients with peripheral vascular disease (group 1), in 11 older control subjects who were matched for blood pressure, age, and sex (group 2), and in 12 younger control subjects (group 3). Diametrical compliance and stiffness index were determined for the common femoral artery, the proximal superficial femoral artery, the distal superficial femoral artery (DSFA), and the midgenicular popliteal artery., Results: All the arterial segments in group 1 showed a trend towards increased stiffness and less compliance than the group 2, age-matched control vessels, with significantly lower distensibility noted at the common femoral artery (mean compliance of 6.2% vs 14.1% mm Hg(-1) x 10(-2), respectively; P <.05) and the DSFA (mean compliance of 2.2% vs 1.9% mm Hg(-1) x 10(-2), respectively; P <.05). The popliteal artery segment in group 3 proved to be more compliant and less stiff than did the same vessel in group 2 (8.5% vs 4.7% mm Hg(-1) x 10(-2), respectively; P <.01). In all three study groups, the DSFA was consistently noted to be the least distensible vessel segment., Conclusion: Lower limb peripheral vascular disease is associated with a reduction in femoropopliteal artery elasticity. Age alone appears to have a minimal effect on the compliance of the proximal half of the femoropopliteal segment. The elastic properties of the femoropopliteal vessel are subject to marked variation along its course. To minimize compliance mismatch, the degree of elasticity engineered into a vascular graft must reflect that observed in vivo.

Background: Pulmonary embolism is a significant cause of morbidity and death after operation. The introduction of new technologies in the diagnosis, and thrombolysis in the treatment, of pulmonary embolism has led to a need to reappraise the management of this condition., Methods: This review encompasses a comprehensive discussion of diagnostic modalities and therapeutic strategies used in the current management of pulmonary embolism. Relevant papers on the diagnosis and treatment of pulmonary embolism were identified from a Medline search for the period 1967-1998. Additional papers were derived from the reference lists of retrieved articles. Articles presenting prospectively gathered data have been referenced preferentially., Results and Conclusion: Algorithms for the diagnosis and treatment of pulmonary embolism are presented.

BACKGROUND: Inferior vena caval filters are a recognized intervention for recurrent pulmonary embolism (PE). Filter utilization in the UK is considerably less than in Europe; this may partly be due to omission of referral of appropriate patients. METHODS: A cohort with the prospect of benefit from caval filter insertion was identified by retrospective study of inpatients who died within 30 days of a positive ventilation-perfusion (V/Q) scan over 2 years. The number of actively managed patients in this group who fulfilled the recognized criteria for caval filter insertion was determined. RESULTS: Fifty-two of 606 patients died within 30 days of scanning. Information was available on 38 (73 per cent) of 52 who had 39 scans (14 positive, 22 negative, three indeterminate). Six of 14 patients (two men and four women, aged 46-84 years) with a positive scan had strong indications for caval filter deployment including contraindication to anticoagulation (three), recurrent PE despite adequate anticoagulation (two) and complications arising from anticoagulation (one). All six died following continuing embolism or complications from anticoagulation. CONCLUSION: Six of 14 patients who died following acute PE required caval filtration but were not offered this intervention. Failure to refer patients who would benefit from filtration may partially account for the disparity in utilization of caval filters between the UK and Europe. Furthermore, because of the choice of death as outcome marker, this study underestimated the value of caval filter utilization.