The sublingual microcirculation and frailty index in chronic kidney disease patients.

OBJECTIVE: To examine the relationship between sublingual microcirculatory measures and frailty index in those attending a kidney transplant assessment clinic. METHODS: Patients recruited had their sublingual microcirculation taken using sidestream dark field videomicroscopy (MicroScan, Micro Vision Medical, Amsterdam, the Netherlands) and their frailty index score using a validated short form via interview. RESULTS: A total of 44 patients were recruited with two being excluded due to microcirculatory image quality scores exceeding 10. The frailty index score indicated significant correlations with total vessel density (p < .0001, r = -.56), microvascular flow index (p = .004, r = -.43), portion of perfused vessels (p = .0004, r = -.52), heterogeneity index (p = .015, r = .32), and perfused vessel density (p < .0001, r = -.66). No correlation was shown between the frailty index and age (p = .08, r = .27). CONCLUSIONS: There is a relationship between the frailty index and microcirculatory health in those attending a kidney transplant assessment clinic, that is not confounded by age. These findings suggest that the impaired microcirculation may be an underlying cause of frailty.

Microcirculatory Impairment Is Associated With Multiple Organ Dysfunction Following Traumatic Hemorrhagic Shock: The MICROSHOCK Study.

OBJECTIVES: To assess the relationship between microcirculatory perfusion and multiple organ dysfunction syndrome in patients following traumatic hemorrhagic shock. DESIGN: Multicenter prospective longitudinal observational study. SETTING: Three U.K. major trauma centers. PATIENTS: Fifty-eight intubated and ventilated patients with traumatic hemorrhagic shock. INTERVENTIONS: Sublingual incident dark field microscopy was performed within 12 hours of ICU admission (D0) and repeated 24 and 48 hours later. Cardiac output was assessed using oesophageal Doppler. Multiple organ dysfunction syndrome was defined as Serial Organ Failure Assessment score greater than or equal to 6 at day 7 post injury. MEASUREMENTS AND MAIN RESULTS: Data from 58 patients were analyzed. Patients had a mean age of 43 ± 19 years, Injury Severity Score of 29 ± 14, and initial lactate of 7.3 ± 6.1 mmol/L and received 6 U (interquartile range, 4-11 U) of packed RBCs during initial resuscitation. Compared with patients without multiple organ dysfunction syndrome at day 7, patients with multiple organ dysfunction syndrome had lower D0 perfused vessel density (11.2 ± 1.8 and 8.6 ± 1.8 mm/mm; p < 0.01) and microcirculatory flow index (2.8 [2.6-2.9] and 2.6 [2.2-2.8]; p < 0.01) but similar cardiac index (2.5 [± 0.6] and 2.1 [± 0.7] L/min//m; p = 0.11). Perfused vessel density demonstrated the best discrimination for predicting subsequent multiple organ dysfunction syndrome (area under curve 0.87 [0.76-0.99]) compared with highest recorded lactate (area under curve 0.69 [0.53-0.84]), cardiac index (area under curve 0.66 [0.49-0.83]) and lowest recorded systolic blood pressure (area under curve 0.54 [0.39-0.70]). CONCLUSIONS: Microcirculatory hypoperfusion immediately following traumatic hemorrhagic shock and resuscitation is associated with increased multiple organ dysfunction syndrome. Microcirculatory variables are better prognostic indicators for the development of multiple organ dysfunction syndrome than more traditional indices. Microcirculatory perfusion is a potential endpoint of resuscitation following traumatic hemorrhagic shock.

Prehospital haemostatic dressings for trauma: a systematic review.

BACKGROUND: Haemorrhage is a major cause of mortality and morbidity following both military and civilian trauma. Haemostatic dressings may offer effective haemorrhage control as part of prehospital treatment. AIM: To conduct a systematic review of the clinical literature to assess the prehospital use of haemostatic dressings in controlling traumatic haemorrhage, and determine whether any haemostatic dressings are clinically superior. METHODS: MEDLINE and EMBASE databases were searched using predetermined criteria. The reference lists of all returned review articles were screened for eligible studies. Two authors independently undertook the search, performed data extraction, and risk of bias and Grading of Recommendations, Assessment, Development and Evaluation quality assessments. Meta-analysis could not be undertaken due to study and clinical heterogeneity. RESULTS: Our search yielded 470 studies, of which 17 met eligibility criteria, and included 809 patients (469 military and 340 civilian). There were 15 observational studies, 1 case report and 1 randomised controlled trial. Indications for prehospital haemostatic dressing use, wound location, mechanism of injury, and source of bleeding were variable. Seven different haemostatic dressings were reported with QuikClot Combat Gauze being the most frequently applied (420 applications). Cessation of bleeding ranged from 67% to 100%, with a median of 90.5%. Adverse events were only reported with QuikClot granules, resulting in burns. No adverse events were reported with QuikClot Combat Gauze use in three studies. Seven of the 17 studies did not report safety data. All studies were at risk of bias and assessed of 'very low' to 'moderate' quality. CONCLUSIONS: Haemostatic dressings offer effective prehospital treatment for traumatic haemorrhage. QuikClot Combat Gauze may be justified as the optimal agent due to the volume of clinical data and its safety profile, but there is a lack of high-quality clinical evidence, and randomised controlled trials are warranted. LEVEL OF EVIDENCE: Systematic review, level IV.

Real-time point of care microcirculatory assessment of shock: design, rationale and application of the point of care microcirculation (POEM) tool.

BACKGROUND: Despite over a decade of research and technological advances, sublingual microcirculatory monitoring has not yet reached clinical utility. Offline analysis is time consuming and occurs away from the patient. A system to assess the microcirculation at the point of care is desirable. We present a novel 5-point grading system (the point of care microcirculation (POEM) scoring system) that can be used at the point of care during non-invasive sublingual microcirculatory monitoring. METHODS: The POEM score is an ordinal scale from 1 (worst) to 5 (best), based on a composite assessment of flow and heterogeneity of four individual sublingual video-microscopy clips. Thirty-two healthcare professionals were trained in how to assign POEM scores. Following training they assigned scores to five test sequences (each consisting of four video clips). They were blinded to clinical status. Inter-user consistency and agreement were assessed using intra-class correlation coefficient (ICC) analysis. In addition, blinded expert scores for 68 video clips were compared to offline computer analysis using traditional microcirculatory parameters including total vessel density (TVD), perfused vessel density (PVD), proportion of perfused vessels (PPV), microcirculatory flow index (MFI) and microcirculatory heterogeneity index (MHI). The time taken to assign each was recorded. RESULTS: Participants showed good inter-rater consistency (ICC 0.83, 95 % CI 0.626, 0.976) and agreement (ICC 0.815, 95 % CI 0.602, 0.974) for assigned POEM scores. Expert scoring of videos correlated with offline values for PVD (R 2 = 0.39; p < 0.05), PPV (R 2 = 0.71; p < 0.001), MFI (R 2 = 0.75; p < 0.001), and MHI (R 2 = 0.68; p < 0.001). POEM scores took less time to assign than conventional offline computer analysis (2 minutes versus 44 minutes). CONCLUSION: We present for the first time a novel 5-point ordinal scale of microcirculatory flow and heterogeneity that can be used at the point of care. It has minimal inter-user variability amongst healthcare professionals after just 1 hour of training. POEM scores take a short time to assign, and correspond well to traditional offline computer-analyzed parameters.

The systemic immune response to trauma: an overview of pathophysiology and treatment.

Improvements in the control of haemorrhage after trauma have resulted in the survival of many people who would otherwise have died from the initial loss of blood. However, the danger is not over once bleeding has been arrested and blood pressure restored. Two-thirds of patients who die following major trauma now do so as a result of causes other than exsanguination. Trauma evokes a systemic reaction that includes an acute, non-specific, immune response associated, paradoxically, with reduced resistance to infection. The result is damage to multiple organs caused by the initial cascade of inflammation aggravated by subsequent sepsis to which the body has become susceptible. This Series examines the biological mechanisms and clinical implications of the cascade of events caused by large-scale trauma that leads to multiorgan failure and death, despite the stemming of blood loss. Furthermore, the stark and robust epidemiological finding--namely, that age has a profound influence on the chances of surviving trauma irrespective of the nature and severity of the injury--will be explored. Advances in our understanding of the inflammatory response to trauma, the impact of ageing on this response, and how this information has led to new and emerging treatments aimed at combating immune dysregulation and reduced immunity after injury will also be discussed.

Novel Textbook Outcomes following emergency laparotomy: Delphi exercise.

BACKGROUND: Textbook outcomes are composite outcome measures that reflect the ideal overall experience for patients. There are many of these in the elective surgery literature but no textbook outcomes have been proposed for patients following emergency laparotomy. The aim was to achieve international consensus amongst experts and patients for the best Textbook Outcomes for non-trauma and trauma emergency laparotomy. METHODS: A modified Delphi exercise was undertaken with three planned rounds to achieve consensus regarding the best Textbook Outcomes based on the category, number and importance (Likert scale of 1-5) of individual outcome measures. There were separate questions for non-trauma and trauma. A patient engagement exercise was undertaken after round 2 to inform the final round. RESULTS: A total of 337 participants from 53 countries participated in all three rounds of the exercise. The final Textbook Outcomes were divided into 'early' and 'longer-term'. For non-trauma patients the proposed early Textbook Outcome was 'Discharged from hospital without serious postoperative complications (Clavien-Dindo ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation or death). For trauma patients it was 'Discharged from hospital without unexpected transfusion after haemostasis, and no serious postoperative complications (adapted Clavien-Dindo for trauma ≥ grade III; including intra-abdominal sepsis, organ failure, unplanned re-operation on or death)'. The longer-term Textbook Outcome for both non-trauma and trauma was 'Achieved the early Textbook Outcome, and restoration of baseline quality of life at 1 year'. CONCLUSION: Early and longer-term Textbook Outcomes have been agreed by an international consensus of experts for non-trauma and trauma emergency laparotomy. These now require clinical validation with patient data.

En-route care capability from point of injury impacts mortality after severe wartime injury.

OBJECTIVE: The objective of this study is to characterize modern point-of-injury (POI) en-route care platforms and to compare mortality among casualties evacuated with conventional military retrieval (CMR) methods to those evacuated with an advanced medical retrieval (AMR) capability. BACKGROUND: Following a decade of war in Afghanistan, the impact of en-route care capabilities from the POI on mortality is unknown. METHODS: Casualties evacuated from POI to one level III facility in Afghanistan (July 2008-March 2012) were identified from UK and US trauma registries. Groups comprised those evacuated by a medically qualified provider-led, AMR and those by a medic-led CMR capability. Outcomes were compared per incremental Injury Severity Score (ISS) bins. RESULTS: Most casualties (n = 1054; 61.2%) were in the low-ISS (1-15) bracket in which there was no difference in en-route care time or mortality between AMR and CMR. Casualties in the mid-ISS bracket (16-50) (n = 583; 33.4%) experienced the same median en-route care time (minutes) on AMR and CMR platforms [78 (58) vs 75 (93); P = 0.542] although those on AMR had shorter time to operation [110 (95) vs 117 (126); P < 0.001]. In this mid-ISS bracket, mortality was lower in the AMR than in the CMR group (12.2% vs 18.2%; P = 0.035). In the high-ISS category (51-75) (n = 75; 4.6%), time to operation was lower in the AMR than the CMR group (66 ± 77 vs 113 ± 122; P = 0.013) but there was no difference in mortality. CONCLUSIONS: This study characterizes en-route care capabilities from POI in modern combat. Conventional platforms are effective in most casualties with low injury severity. However, a definable injury severity exists for which evacuation with an AMR capability is associated with improved survival.

Clinical review: Statins and trauma--a systematic review.

Statins, in addition to their lipid-lowering properties, have anti-inflammatory actions. The aim of this review is to evaluate the effect of pre-injury statin use, and statin treatment following injury. MEDLINE, EMBASE, and CENTRAL databases were searched to January 2012 for randomised and observational studies of statins in trauma patients in general, and in patients who have suffered traumatic brain injury, burns, and fractures. Of 985 identified citations, 7 (4 observational studies and 3 randomised controlled trials (RCTs)) met the inclusion criteria. Two studies (both observational) were concerned with trauma patients in general, two with patients who had suffered traumatic brain injury (one observational, one RCT), two with burns patients (one observational, one RCT), and one with fracture healing (RCT). Two of the RCTs relied on surrogate outcome measures. The observational studies were deemed to be at high risk of confounding, and the RCTs at high risk of bias. Three of the observational studies suggested improvements in a number of clinical outcomes in patients taking statins prior to injury (mortality, infection, and septic shock in burns patients; mortality in trauma patients in general; mortality in brain injured patients) whereas one, also of trauma patients in general, showed no difference in mortality or infection, and an increased risk of multi-organ failure. Two of three RCTs on statin treatment in burns patients and brain injured patients showed improvements in E-selectin levels and cognitive function. The third, of patients with radial fractures, showed no acceleration in fracture union. In conclusion, there is some evidence that pre-injury statin use and post-injury statin treatment may have a beneficial effect in patients who have suffered general trauma, traumatic brain injury, and burns. However, these studies are at high risk of confounding and bias, and should be regarded as 'hypothesisgenerating'. A well-designed RCT is required to determine the therapeutic efficacy in improving outcomes in this patient population.

Fascial layers encountered in the lateral skull base region: A cadaveric and radiological analysis.

BACKGROUND: In our experience, the anterior carotid sheath forms an important plane of dissection when excising temporal bone region cancers. However, its anatomical composition, relationships, and radiological appearance remains unclear. METHODS: Eight sides of cadaveric heads were dissected. Anatomical findings were correlated with a high-resolution baseline T1 MRI. RESULTS: The anterior carotid sheath was formed by the tensor-vascular-styloid fascia, stylopharyngeal fascia, buccopharyngeal fascia (BPF), and longus capitis fascia (LCF), and appeared as a hypointense line on MRI. Not previously described, the glossopharyngeal nerve pierced the sheath 9.0 mm (SD 2.1 mm) below the skull base and traveled through its LCF and BPF layers to exit near the pharynx. CONCLUSION: Multiple fascial layers formed the anterior carotid sheath at the skull base, and this was radiologically identifiable. Further studies are required to validate findings and investigate the role this fascial plane has in forming an effective barrier to spread of malignancy.

Interobserver reliability for manual analysis of sidestream darkfield videomicroscopy clips after resizing in ImageJ.

BACKGROUND: Direct assessment of microcirculatory function remains a critical care research tool but approaches for analysis of microcirculatory videomicroscopy clips are shifting from manual to automated algorithms, with a view to clinical application in the intensive care unit. Automated analysis software associated with current sidestream darkfield videomicroscopy systems is demonstrably unreliable; therefore, semi-automated analysis of captured clips should be undertaken in older generations of software. We present a method for capture of microcirculatory clips using current version videomicroscope hardware and resizing of clips to allow compatibility with legacy analysis software. The interobserver reliability of this novel approach is examined, in addition to a comparison of this approach with the current generation of automated analysis software. RESULTS: Resizing microcirculatory clips did not significantly change image quality. Assessment of bias between observers for manual analysis of resized clips; and between manually analysed clips and automated software analysis was undertaken by Bland-Altman analysis. Bias was demonstrated for all parameters for manual analysis of resized clips (total vessel density = 6.8, perfused vessel density = 6.3, proportion of perfused vessels = - 8.79, microvascular flow index = - 0.08). Marked bias between manual analysis and automated analysis was also evident (total vessel density = 16.6, perfused vessel density = 16.0, proportion of perfused vessels = 1.8). The difference between manual and automated analysis was linearly related to the magnitude of the measured parameter. CONCLUSIONS: Poor reliability of automated analysis is a significant hurdle for clinical translation of microcirculatory monitoring. The method presented here allows capture of microcirculatory clips using current hardware that are backwards compatible with older versions of manual analysis software. We conclude that this approach is appropriate for research applications in the intensive care unit, however the time delay to results limits utility for clinical translation.

Combat-related craniofacial and cervical injuries: a 5-year review from the British military.

BACKGROUND: Recent international publications have noted a sustained increase in the incidence of head, face, and neck (HFN) wounds in comparison with total battle injuries from the 20th to the 21st century. The aim of this review was therefore to perform an analysis of the epidemiology of all HFN injuries sustained by British forces in Iraq and Afghanistan from March 1, 2003, to December 31, 2008. METHODS: Descriptive injury data for this research were obtained from the Joint Theater Trauma Registry and overall battle injury and evacuation figures from the Defense Analytical and Statistical Agency. RESULTS: During this period, 448 servicemen sustained injuries to their HFN. A total of 71% of HFN injuries were sustained in battle. Of all service personnel sustaining HFN injuries, 32% died before the field hospital and a further 6% died subsequently. A total of 73% of injuries required evacuation back to the United Kingdom, whereas 27% of injuries were managed definitively in the theater of operations. HFN injuries altogether were found in 29% of battle injuries between 2006 and 2008. CONCLUSIONS: The individual incidences of head (15%) and face (19%) injuries in relation to total battle injuries, although greater than seen in previous United Kingdom conflicts, were only slightly higher than that seen by US forces. The incidence of neck injury alone in relation to total battle injuries of 11% in United Kingdom forces in comparison with 3% to 5% found in US forces warrants further investigation. This article also provides further evidence to support the existing published opinion of multiple international authors in the requirement to develop innovative methods of protecting the vulnerable HFN regions.

Feasibility of using rotational thromboelastometry to assess coagulation status of combat casualties in a deployed setting.

BACKGROUND: Coagulopathy in trauma patients is currently defined by the results of standard laboratory tests (prothrombin time and activated partial thromboplastin time). These results offer little in the hemostatic resuscitation that occurs in the treatment of battlefield patients who receive massive transfusions. Thromboelastometry (TEM) is a technique that can offer rapid, near-patient testing of coagulation status. METHODS: A prospective observational field study was performed in a deployed military setting to determine the feasibility of using TEM to assess the coagulation status of patients admitted to the emergency department and who subsequently received a massive transfusion. RESULTS: TEM was performed on 31 patients, 25 were direct admissions to the emergency department, 19 of whom were enrolled into the massive transfusion protocol, and 60% were involved in a blast incident. Standard laboratory testing showed that 10% of all patients were coagulopathic on admission compared with 64% with an abnormal TEM trace (p = 0.0005). All patients had abnormal maximum clot firmness. The TEM amplitude at 10 minutes is associated with the subsequent development of abnormal maximum clot firmness. Two exemplar cases are discussed, which illustrate the potential benefit of using TEM to monitor and guide and individualize therapy during a massive transfusion. CONCLUSIONS: It is feasible to use TEM in a deployed military setting. We have shown that rotational thromboelastometry significantly detects more abnormalities in the coagulation status than the standard laboratory tests (prothrombin time, and activated partial thromboplastin time).

Combat vascular injury: Influence of mechanism of injury on outcome.

BACKGROUND: Haemorrhage is the leading cause of death on the battlefield. Seventy percent of injuries are due to explosive mechanisms. Anecdotally, these patients have had poorer outcomes when compared to those with penetrating mechanisms of injury (MOI). We wished to test the hypothesis that outcomes following vascular reconstruction were worse in blast-injured than non blast-injured patients. METHODS: Retrospective cohort study. British and American combat casualties with arterial injuries sustained in Iraq or Afghanistan (2003-2014) were identified from the UK Joint Theatre Trauma Registry (JTTR). Eligibility included explosive or penetrating MOI, with follow-up to UK hospital discharge, or death. Outcomes were mortality, amputation, graft thrombosis, haemorrhage, and infection. Statistical analysis was performed using Pearson Chi-Square test, t-tests, ANOVA or non-parametric equivalent, and survival analyses. RESULTS: One hundred and fifteen patients were included, 80 injured by explosive and 35 by penetrating mechanisms. Evacuation time, ISS, number of arterial injuries, age and gender were comparable between groups. Seventy percent of arterial injuries resulted from an explosive MOI. The explosive injuries group received more blood products (p = 0.008) and suffered more regions injured (p < 0.0001). Early surgical interventions in both were ligation (n = 36, 31%), vein graft (n = 33, 29%) and shunting (n = 9, 8%). Mortality (n = 12, 10%) was similar between groups. Differences in limb salvage rates following explosive (n = 17, 53%) vs penetrating (n = 13, 76.47%) mechanisms approached statistical significance (p = 0.056). Nine (28%) vein grafted patients developed complications. No evidence of a difference in the incidence of vein graft thrombosis was found when comparing explosive with non-explosive cohorts (p = 0.154). CONCLUSIONS: The recorded numbers of vein grafts following combat arterial trauma in are small in the JTTR. No statistically-significant differences in complications, including vein graft thrombosis, were found between cohorts injured by explosive and non-explosive mechanisms.

Impact of plasma viscosity on microcirculatory flow after traumatic haemorrhagic shock: A prospective observational study.

BACKGROUND: Preclinical studies report that higher plasma viscosity improves microcirculatory flow after haemorrhagic shock and resuscitation, but no clinical study has tested this hypothesis. OBJECTIVE: We investigated the relationship between plasma viscosity and sublingual microcirculatory flow in patients during resuscitation for traumatic haemorrhagic shock (THS). METHODS: Sublingual video-microscopy was performed for 20 trauma patients with THS as soon as feasible in hospital, and then at 24 h and 48 h. Values were obtained for total vessel density, perfused vessel density, proportion of perfused vessels, microcirculatory flow index (MFI), microcirculatory heterogeneity index (MHI), and Point of Care Microcirculation (POEM) scores. Plasma viscosity was measured using a Wells-Brookfield cone and plate micro-viscometer. Logistic regression analyses examined relationships between microcirculatory parameters and plasma viscosity, adjusting for covariates (systolic blood pressure, heart rate, haematocrit, rate and volume of fluids, and rate of noradrenaline). RESULTS: Higher plasma viscosity was not associated with improved microcirculatory parameters. Instead, there were weakly significant associations between higher plasma viscosity and lower (poorer) MFI (p = 0.040), higher (worse) MHI (p = 0.033), and lower (worse) POEM scores (p = 0.039). CONCLUSIONS: The current study did not confirm the hypothesis that higher plasma viscosity improves microcirculatory flow dynamics in patients with THS. Further clinical investigations are warranted to determine whether viscosity is a physical parameter of importance during resuscitation of these patients.

Poor microcirculatory flow dynamics are associated with endothelial cell damage and glycocalyx shedding after traumatic hemorrhagic shock.

BACKGROUND: Endothelial cell damage and glycocalyx shedding after trauma can increase the risk of inflammation, coagulopathy, vascular permeability, and death. Bedside sublingual video-microscopy may detect worse flow and perfusion associated with this endotheliopathy. We compared markers of endotheliopathy with physical flow dynamics after traumatic hemorrhagic shock. METHODS: Sublingual incident dark field video-microscopy was performed at three time points after injury (<10 hours, 10-30 hours, and 30-50 hours). Values for microcirculatory flow index (MFI), Point Of carE Microcirculation assessment (POEM) score, proportion of perfused vessels (PPV), microcirculatory heterogeneity index (MHI), perfused vessel density (PVD), and total vessel density (TVD) were obtained. ELISAs were performed to measure concentrations of thrombomodulin and syndecan-1 as biomarkers of endothelial cell damage and glycocalyx shedding respectively. Flow parameters were dichotomized to above and below average, and biomarkers compared between groups; below average MFI, POEM, PPV, PVD, and TVD, and above average MHI were considered poor microcirculatory flow dynamics. RESULTS: A total of 155 sublingual video-microscopy clips corresponding to 39 time points from 17 trauma patients were analyzed. Median age was 35 (IQR 25-52); 16/17 were men. Within 10 hours of injury, syndecan-1 concentrations were significantly higher compared to 17 age- and sex-matched healthy controls (30 [IQR 20-44] ng/mL) for worse TVD (78 [IQR 63-417] ng/mL), PVD (156 [IQR 63-590] ng/mL), PPV (249 [IQR 64-578] ng/mL), MFI (249 [IQR 64-578] ng/mL), MHI (45 [IQR] 38-68) ng/mL), and POEM scores (108 [IQR 44-462] ng/mL) (all p < 0.01). Thrombomodulin was also raised within 10 hours of injury when compared to healthy controls (2.9 [IQR 2.2-3.4] ng/mL) for worse PPV (4.1 [IQR 3.4-6.2] ng/mL) and MFI (4.1 [IQR 3.4-6.2] ng/mL) (both p < 0.05). CONCLUSIONS: Endothelial cell damage and glycocalyx shedding are associated with worse flow, density, and heterogeneity within microvessels after traumatic hemorrhagic shock. The clinical utility of these biomarkers and flow parameters at the bedside are yet to be elucidated. LEVEL OF EVIDENCE: Prognostic study, level III.

Refining the Trauma and Injury Severity Score (TRISS) to Measure the Performance of the UK Combat Casualty Care System.

INTRODUCTION: The Trauma and Injury Severity Score (TRISS) methodology is used in both the UK and US Military trauma registries. The method relies on dividing casualties according to mechanism, penetrating or blunt, and uses different weighting coefficients accordingly. The UK Military Joint Theatre Trauma Registry uses the original coefficients devised in 1987, whereas the US military registry uses updated civilian coefficients, but it is not clear how either registry analyzes explosive casualties according to the TRISS methodology. This study aims to use the UK Military Joint Theatre Trauma Registry to calculate new TRISS coefficients for contemporary battlefield casualties injured by either gunshot or explosive mechanisms. The secondary aim of this study is to apply the revised TRISS coefficients to examine the survival trends of UK casualties from recent military conflicts. MATERIALS AND METHODS: The Joint Theatre Trauma Registry was searched for all UK casualties injured or killed in Iraq and Afghanistan by explosive or gunshot mechanisms between January 1, 2003 and December 31, 2014. Details of these casualties including injuries and vital signs were reviewed. Logistic regression analysis was performed to devise new TRISS coefficients; these were then used to examine survival over the 12 yr of the study. RESULTS: Comparing the predictions from the gunshot TRISS model to the observed outcomes, it demonstrates a sensitivity of 98.1% and a specificity of 96.8% and an overall accuracy of 97.8%. With respect to the explosive TRISS model, there is a sensitivity of 98.6%, a specificity of 97.4%, and an overall accuracy of 98.4%. When this updated and mechanism-specific TRISS methodology was used to measure changes in survival over the study period, survival following these injuries improved until 2012 when performance was maintained for the last 2 yr of the study. CONCLUSION: This study for the first time refines the TRISS methodology with coefficients appropriate for use within combat casualty care systems. This improved methodology reveals that UK combat casualty care performance appears to have improved until 2012 when this standard was maintained.

Endotheliopathy of Trauma is an on-Scene Phenomenon, and is Associated with Multiple Organ Dysfunction Syndrome: A Prospective Observational Study.

BACKGROUND: Trauma patients are vulnerable to coagulopathy and inflammatory dysfunction associated with endotheliopathy of trauma (EoT). In vitro evidence has suggested that tranexamic acid (TXA) may ameliorate endotheliopathy. We aimed to investigate how soon after injury EoT occurs, its association with multiple organ dysfunction syndrome (MODS), and whether TXA ameliorates it. METHODS: A prospective observational study included 91 trauma patients enrolled within 60 min of injury and 19 healthy controls. Blood was sampled on enrolment and again 4 to 12 h later. ELISAs measured serum concentrations of syndecan-1 and thrombomodulin as biomarkers of EoT. MODS was compared between groups according to biomarker dynamics: persistently abnormal; abnormal to normal; and persistently normal. Timing of EoT was estimated by plotting biomarker data against time, and then fitting generalized additive models. Biomarker dynamics were compared between those who did or did not receive prehospital TXA. RESULTS: Median age was 38 (interquartile range [IQR] 24-55) years; 78 of 91 were male. Median injury severity score (ISS) was 22 (IQR 12-36). EoT was estimated to occur at 5 to 8 min after injury. There were no significant differences in ISS between those with or without prehospital EoT. Forty-two patients developed MODS; 31 of 42 with persistently abnormal; 8 of 42 with abnormal to normal; and 3 of 42 with persistently normal biomarkers; P < 0.05. There were no significant differences between TXA and non-TXA groups. CONCLUSIONS: EoT was present at the scene of injury. MODS was more likely when biomarkers of EoT were persistently raised. There were no significant differences between TXA and non-TXA groups. Prehospital interventions aimed at endothelial restoration may represent a clinically meaningful target for prehospital resuscitation.

What fluids are given during air ambulance treatment of patients with trauma in the UK, and what might this mean for the future? Results from the RESCUER observational cohort study.

OBJECTIVES: We investigated how often intravenous fluids have been delivered during physician-led prehospital treatment of patients with hypotensive trauma in the UK and which fluids were given. These data were used to estimate the potential national requirement for prehospital blood products (PHBP) if evidence from ongoing trials were to report clinical superiority. SETTING: The Regional Exploration of Standard Care during Evacuation Resuscitation (RESCUER) retrospective observational study was a collaboration between 11 UK air ambulance services. Each was invited to provide up to 5 years of data and total number of taskings during the same period. PARTICIPANTS: Patients with hypotensive trauma (systolic blood pressure <90 mm Hg or absent radial pulse) attended by a doctor. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the number of patients with hypotensive trauma given prehospital fluids. Secondary outcomes were types and volumes of fluids. These data were combined with published data to estimate potential national eligibility for PHBP. RESULTS: Of 29 037 taskings, 729 (2.5%) were for patients with hypotensive trauma attended by a physician. Half were aged 21-50 years; 73.4% were male. A total of 537 out of 729 (73.7%) were given fluids. Five hundred and ten patients were given a single type of fluid; 27 received >1 type. The most common fluid was 0.9% saline, given to 486/537 (90.5%) of patients who received fluids, at a median volume of 750 (IQR 300-1500) mL. Three per cent of patients received PHBP. Estimated projections for patients eligible for PHBP at these 11 services and in the whole UK were 313 and 794 patients per year, respectively. CONCLUSIONS: One in 40 air ambulance taskings were manned by physicians to retrievepatients with hypotensive trauma. The most common fluid delivered was 0.9% saline. If evidence justifies universal provision of PHBP, approximately 800 patients/year would be eligible in the UK, based on our data combined with others published. Prospective investigations are required to confirm or adjust these estimations.

Prehospital rapid sequence induction following trauma in the era of regional networks for major trauma.

OBJECTIVE: Rapid sequence induction (RSI) provides prompt airway control during emergency evacuation of trauma patients. Physicians may be tasked to travel with paramedic ambulance crews to the scene of injury when RSI is more likely to be required. This study investigates whether there are any differences in the practice of prehospital RSI during emergency retrievals for trauma since the establishment of the regional Major Trauma Network (MTN) in March 2012. METHODS: A retrospective observational study examined prehospital records for all trauma patients from September 2010 to January 2015 at a Major Trauma Centre in Birmingham, UK. Prehospital physician availability increased from 12 to 24 h after March 2012, and tasking became centralized. Data included demographics, mechanism of injury, crew personnel, and details of RSI. The periods before and after the establishment of the regional MTN were compared. RESULTS: There were 5244 patients: 1432 (27.3%) before and 3812 (72.7%) after March 2012. Of the patients, 67.2% were male. The most common injuries were road traffic collisions (45.0%). Physicians were more likely to be present after (2345 missions, 61.5%) than before (529 missions, 36.9%) March 2012 (P<0.01). RSI was performed 434 (8.3%) times and was more likely during the latter than the former period [359 (9.4%) vs. 75 (5.2%), P<0.01]. Successful tracheal intubation was achieved in 99% of occasions. CONCLUSION: The establishment of regional MTNs enables centrally tasked, 24-h physician availability for emergency trauma patients. There has been an increase in physician presence on emergency missions and increased frequency of RSI for at-risk trauma patients at times when there may previously have been an unmet requirement.