UK Joint Theatre Trauma Registry Research Articles

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

IntroductionLife-threatening haemorrhage is the leading cause of potentially survivable injury in battlefield casualties. During Operation HERRICK (Afghanistan), mortality rates improved year on year due to a number of advances in...

Predicting the Outcome of Limb Revascularization in Patients With Lower-extremity Arterial Trauma: Development and External Validation of a Supervised Machine-learning Algorithm to Support Surgical Decisions.

Estimating the likely success of limb revascularization in patients with lower-extremity arterial trauma is central to decisions between attempting limb salvage and amputation. However, the projected outcome is often unclear at the time these decisions need to be made, making them difficult and threatening sound judgement. The objective of this study was to develop and validate a prediction model that can quantify an individual patient's risk of failed revascularization. A BN prognostic model was developed using domain knowledge and data from the US joint trauma system. Performance (discrimination, calibration, and accuracy) was tested using ten-fold cross validation and externally validated on data from the UK Joint Theatre Trauma Registry. BN performance was compared to the mangled extremity severity score. Rates of amputation performed because of nonviable limb tissue were 12.2% and 19.6% in the US joint trauma system (n = 508) and UK Joint Theatre Trauma Registry (n = 51) populations respectively. A 10-predictor BN accurately predicted failed revascularization: area under the receiver operating characteristic curve (AUROC) 0.95, calibration slope 1.96, Brier score (BS) 0.05, and Brier skill score 0.50. The model maintained excellent performance in an external validation population: AUROC 0.97, calibration slope 1.72, Brier score 0.08, Brier skill score 0.58, and had significantly better performance than mangled extremity severity score at predicting the need for amputation [AUROC 0.95 (0.92-0.98) vs 0.74 (0.67-0.80); P < 0.0001]. A BN (https://www.traumamodels.com) can accurately predict the outcome of limb revascularization at the time of initial wound evaluation. This information may complement clinical judgement, support rational and shared treatment decisions, and establish sensible treatment expectations.

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

IntroductionThe majority of combat deaths occur before arrival at a medical treatment facility but no previous studies have comprehensively examined this phase of care.MethodsThe UK Joint Theatre Trauma Registry was...

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

ObjectivesCatastrophic haemorrhage is a leading cause of morbidity and mortality in trauma, in both military and civilian settings. There are numerous studies looking at the effectiveness of different haemostatic agents...

Outcomes following trauma laparotomy for hypotensive trauma patients: A UK military and civilian perspective

The management of trauma patients has changed radically in the last decade, and studies have shown overall improvements in survival. However, reduction in mortality for the many may obscure a lack of progress in some high-risk patients. We sought to examine the outcomes for hypotensive patients requiring laparotomy in UK military and civilian cohorts. We undertook a review of two prospectively maintained trauma databases: the UK Joint Theatre Trauma Registry for the military cohort (February 4, 2003, to September 21, 2014) and the trauma registry of the Royal London Hospital major trauma center (January 1, 2012, to January 1, 2017) for civilian patients. Adults undergoing trauma laparotomy within 90 minutes of arrival at the emergency department (ED) were included. Hypotension was present on arrival at the ED in 155 (20.4%) of 761 military patients. Mortality was higher in hypotensive casualties (25.8% vs. 9.7% in normotensive casualties; p < 0.001). Hypotension was present on arrival at the ED in 63 (35.7%) of 176 civilian patients. Mortality was higher in hypotensive patients (47.6% vs. 12.4% in normotensive patients; p < 0.001). In both cohorts of hypotensive patients, neither the average injury severity, the prehospital time, the ED arrival systolic blood pressure, nor mortality rate changed significantly during the study period. Despite improvements in survival after trauma for patients overall, the mortality for patients undergoing laparotomy who arrive at the ED with hypotension has not changed and appears stubbornly resistant to all efforts. Specific enquiry and research should continue to be directed at this high-risk group of patients. Prognostic/Epidemiologic, level IV.

Combat vascular injury: Influence of mechanism of injury on outcome

BackgroundHaemorrhage 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. MethodsRetrospective 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. ResultsOne 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). ConclusionsThe 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.

Characterization of Lower Extremity Blast Injury.

Throughout history, traumatic amputation of the lower extremity has been a notable feature of all conflicts involving explosive incidents. Even at the close of the recent conflicts in Afghanistan, there were deaths that were deemed "potentially survivable." The purpose of this study is to characterize lower extremity blast injury and to determine if their amputation levels and associated injury characteristics correlate with a higher risk of mortality. the UK Joint Theatre Trauma Registry (JTTR) was interrogated to identify all lower extremity traumatic amputations sustained in both Iraq and Afghanistan between January 2003 and the end of UK operations in August 2014. The mortality rates for each amputation level and associated injuries were determined. Of the 977 casualties, there were 679 (69.5%) survivors and 298 fatalities (30.5%). There was an increase in survivability from traumatic amputation throughout the conflict, however, traumatic amputations at the close of military activity in 2014 still had a substantial fatality rate of 23%. A more proximal level of amputation, an associated pelvic fracture, and an associated abdominal injury all correlated with an increased mortality rate. Several specific injury characteristics associated with traumatic amputation have been identified that are associated with an increased mortality rate to include a more proximal amputation level, pelvic fracture, and abdominal injury. Injury prevention and mitigation measures should be explored to minimize the risk of the associated injuries following blast that portend a higher risk of mortality.

14 Prediction of massive blood transfusion in battlefield trauma: development and validation of the military acute severe haemorrhage (MASH) score

BackgroundThe predominant cause of preventable death from trauma is bleeding. Many patients need resuscitation with massive blood transfusion (MBT). In some theatres of military operation there is limited blood product...

The pattern of paediatric blast injury in Afghanistan

IntroductionBetween 2009 and 2015, 3746 children died, and 7904 were injured as a result of armed conflict within Afghanistan. Improvised explosive devices (IEDs) and explosive remnants of war accounted for...

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

BackgroundThe 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...

Prediction of massive blood transfusion in battlefield trauma: Development and validation of the Military Acute Severe Haemorrhage (MASH) score

BackgroundThe predominant cause of preventable trauma death is bleeding, and many of these patients need resuscitation with massive blood transfusion. In resource-constrained environments, early recognition of such patients can improve planning and reduce wastage of blood products. No existing decision rule is sufficiently reliable to predict those patients requiring massive blood transfusion. This study aims to produce a decision rule for use on arrival at hospital for patients sustaining battlefield trauma. MethodsA retrospective database analysis was undertaken using the UK Joint Theatre Trauma Registry to provide a derivation and validation dataset. Regression analysis of potential predictive factors was performed. Predictive factors were analysed through multi-logistic regression analysis to build predictive models; sensitivity and specificity of these models was assessed, and the best fit models were analysed in the validation dataset. ResultsA decision rule was produced using a combination of injury pattern, clinical observations and pre-hospital data. The proposed rule, using a score of 3 or greater, demonstrated a sensitivity of 82.7% and a specificity of 88.8% for prediction of massive blood transfusion, with an AUROC of 0.93 (95% CI 0.91–0.95). ConclusionsWe have produced a decision tool with improved accuracy compared to any previously described tools that can be used to predict blood transfusion requirements in the military deployed hospital environment.

Mediastinal injury is the strongest predictor of mortality in mounted blast amongst UK deployed forces

BackgroundBlast injury has been the most common cause of morbidity and mortality encountered by UK forces during recent conflicts. Injuries sustained by blast are categorised by the injuring component of the explosion and depend upon physical surroundings. Previous work has established that head injuries and intra cavity haemorrhage are the major causes of death following exposure to under body (mounted) blast but has yet to explore the precise nature of these torso injuries nor the effect of particular injuries upon survival. This study examines the patterns of torso injury within the mounted blast environment in order to understand the effect of these injuries upon survivability. MethodsThis retrospective study examined the UK Joint Theatre Trauma Registry to determine precise injury patterns of mounted blast casualties within a 13year period of UK military deployments. Survival rates of individual injuries were compared and a multivariable logistic regression model was developed in order to assess the effect that each injury had upon likelihood of death. Results426 mounted casualties were reviewed of whom 129 did not survive. Median NISS and ISS for non-survivors was found to be 75. Torso injuries were significantly more common amongst non-survivors than survivors and high case fatality rates were associated with all haemorrhagic torso injuries. Multivariable analysis shows that mediastinal injuries have the largest odds ratio for mortality (20.4) followed by lung laceration and head injury. ConclusionsNon-compressible torso haemorrhage is associated with mortality amongst mounted blast. Of this group, mediastinal injury is the strongest predictor of death and could be considered as a surrogate marker of lethality. Future work to link blast loading characteristics with specific injury patterns will inform the design of mitigating strategies in order to improve survivability of underbody blast

Salvage of Combat Hindfoot Fractures in 2003-2014 UK Military.

Hindfoot fractures pose a considerable challenge to military orthopaedic surgeons, as combat injuries are typically the result of energy transfers not seen in civilian practice. This study aimed to characterize the pattern of hindfoot injuries sustained by UK military casualties in recent conflicts, define the early amputation and infection rate, and identify factors associated with poor early outcomes. The UK Joint Theatre Trauma Registry was searched for British military casualties sustaining a hindfoot fracture from Iraq and Afghanistan between 2003 and 2014. Data on the injury pattern and management were obtained along with 18-month follow-up data. Statistical analysis was performed with the chi-square test and binomial logistic regression analysis. The threshold for significance was set at P < .05. One hundred fourteen patients sustained 134 hindfoot injuries. Eighteen-month follow-up was available for 92 patients (81%) and 114 hindfeet (85%). The calcaneus was fractured in 116 cases (87%): 54 (47%) were managed conservatively, 32 (28%) underwent K-wire fixation, and 30 (26%) underwent internal fixation. Nineteen patients (17%) required transtibial amputation during this time. A deep infection requiring operative treatment occurred in 13 cases (11%) with Staphylococcus aureus, the most common infectious organism (46%). A deep infection was strongly associated with operative fracture management ( P = .0016). When controlling for multiple variables, the presence of a deep infection was significantly associated with a requirement for amputation at 18 months ( P = .023). There was no association between open fractures and a requirement for amputation at 18 months ( P = .640), nor was conservative management associated with a requirement for amputation ( P = .999). Thirty-six fractures (32%) required unplanned revision surgery within the first 18 months following salvage, of which 19 (53%) involved amputation. A deep infection was the sole variable significantly associated with a requirement for amputation by 18 months. These results suggest that attempts at salvaging these injuries are at the limits of orthopaedic technical feasibility. Level III, comparative series.

Major incident triage: Derivation and comparative analysis of the Modified Physiological Triage Tool (MPTT)

BackgroundTriage is a key principle in the effective management at a major incident. There are at least three different triage systems in use worldwide and previous attempts to validate them, have revealed limited sensitivity. Within a civilian adult population, there has been no work to develop an improved system. MethodsA retrospective database review of the UK Joint Theatre Trauma Registry was performed for all adult patients (>18years) presenting to a deployed Military Treatment Facility between 2006 and 2013. Patients were defined as Priority One if they had received one or more life-saving interventions from a previously defined list.Using first recorded hospital physiological data (HR/RR/GCS), binary logistic regression models were used to derive optimum physiological ranges to predict need for life-saving intervention. This allowed for the derivation of the Modified Physiological Triage Tool–MPTT (GCS≥14, HR≥100, 12<RR≥22). A comparison of the MPTT and existing triage tools was then performed using sensitivities and specificities with 95% confidence intervals. Differences in performance were assessed for statistical significance using a McNemar test with Bonferroni correction. ResultsOf 6095 patients, 3654 (60.0%) had complete data and were included in the study, with 1738 (47.6%) identified as priority one. Existing triage tools had a maximum sensitivity of 50.9% (Modified Military Sieve) and specificity of 98.4% (Careflight). The MPTT (sensitivity 69.9%, 95% CI 0.677-0.720, specificity 65.3%, 95% CI 0.632-0.675) showed an absolute increase in sensitivity over existing tools ranging from 19.0% (Modified Military Sieve) to 45.1% (Triage Sieve). There was a statistically significant difference between the performance (p<0.001) between the MPTT and the Modified Military Sieve. Discussion & conclusionThe performance characteristics of the MPTT exceed existing major incident triage systems, whilst maintaining an appropriate rate of over-triage and minimising under-triage within the context of predicting the need for a life-saving intervention in a military setting. Further work is required to both prospectively validate this system and to identify its performance within a civilian environment, prior to recommending its use in the major incident setting.

Penetrating abdominal injury: UK military experience from the Afghanistan conflict

To identify the prevalence, injury patterns and mortality of penetrating abdominal injury in patients treated at the UK Role 3 Medical Treatment Facility (MTF) in Camp Bastion, Afghanistan. All patients with a penetrating abdominal injury were identified from the UK Joint Theatre Trauma Registry (JTTR). Demographics, predicted survival and observed mortality were compared. Sub-group analyses of UK military patients were conducted, comparing changes in survival as the campaign progressed and identifying the anatomical distribution of abdominal injuries. Between June 2006 and June 2013, 1331 of the 8558 (16%) patients recorded on the JTTR had a penetrating abdominal injury; 393 were UK military, of whom 175 (45%) survived. 71% of UK military fatalities had the maximum New Injury Severity Score (NISS) of 75 compared to 4.6% of UK military survivors. The survival rate of UK military patients increased in the later stages of the campaign. Fatal injury in UK military patients was associated with significant vascular or hepatic injuries. This study has defined the epidemiology of penetrating abdominal injury in a modern conflict. Continued training and further research into injury prevention and management will help to ensure that the improved outcomes observed in Afghanistan continue on future operations.

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

BackgroundThe 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...

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

BackgroundTraumatic 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...

Traumatic Brain Injury Recorded in the UK Joint Theatre Trauma Registry Among the UK Armed Forces

To use the UK Joint Theatre Trauma Registry (UK-JTTR) to identify service personnel sustaining traumatic brain injury (TBI) in recent conflicts and to examine injury characteristics, outcomes, and severity measures predictive of survival. Operations HERRICK (Afghanistan) and TELIC (Iraq). The UK-JTTR records data for every UK service person either killed on operations or treated by Defence Medical Services after a trauma call, including those evacuated for inpatient care following traumatic injury. UK-JTTR data were retrospectively analyzed to identify those who sustained TBI. The Mayo system was used to define TBI. Glasgow Coma Scale score, injury severity score, new injury severity score, trauma injury severity score, abbreviated injury scale, and a severity characterization of trauma were used to predict survival. In total, 464 UK service personnel sustained TBI, representing 19% of the 2440 casualties in Afghanistan and Iraq, recorded in the UK-JTTR. Most TBI casualties had moderate-severe TBI (402, 87%). There were 181 (39%) survivors, 56% of these received neurorehabilitation. Improvised explosive devices accounted for 55% of TBIs sustained in Afghanistan and 31% of TBIs in Iraq. Logistic regression analyses were performed using the 412 cases (149 survivors: 263 fatalities) with scores on all severity measures. The best-fitting model was based on trauma injury severity score. A trauma injury severity score more than 11.13 indicates a more than 95% probability of survival. This is the first study of UK combat TBIs between 2003 and 2011. Almost 1 in 5 UK service personnel recorded in the UK-JTTR had TBI; most were moderate-severe. However, mild TBI is likely to be underrepresented in the UK-JTTR. These findings may be used to plan future rehabilitation needs, as almost half the survivors did not receive neurorehabilitation.

Interobserver Variability in Injury Severity Scoring After Combat Trauma: Different Perspectives, Different Values?

Anatomic measures of injury burden provide key information for studies of prehospital and in-hospital trauma care. The military version of the Abbreviated Injury Scale [AIS(M)] is used to score injuries in deployed military hospitals. Estimates of total trauma burden are derived from this. These scores are used for categorization of patients, assessment of care quality, and research studies. Scoring is normally performed retrospectively from chart review. We compared data recorded in the UK Joint Theatre Trauma Registry (JTTR) and scores calculated independently at the time of surgery by the operating surgeons to assess the concordance between surgeons and trauma nurse coordinators in assigning injury severity scores. Trauma casualties treated at a deployed Role 3 hospital were assigned AIS(M) scores by surgeons between 24 September 2012 and 16 October 2012. JTTR records from the same period were retrieved. The AIS(M), Injury Severity Score (ISS), and New Injury Severity Score (NISS) were compared between datasets. Among 32 matched casualties, 214 injuries were recorded in the JTTR, whereas surgeons noted 212. Percentage agreement for number of injuries was 19%. Surgeons scored 75 injuries as "serious" or greater compared with 68 in the JTTR. Percentage agreement for the maximum AIS(M), ISS, and NISS assigned to cases was 66%, 34%, and 28%, respectively, although the distributions of scores were not statistically different (median ISS: surgeons: 20 [interquartile range (IQR), 9-28] versus JTTR: 17.5 [IQR, 9-31.5], p = .7; median NISS: surgeons: 27 [IQR, 12-42] versus JTTR: 25.5 [IQR, 11.5-41], p = .7). There are discrepancies in the recording of AIS(M) between surgeons directly involved in the care of trauma casualties and trauma nurse coordinators working by retrospective chart review. Increased accuracy might be achieved by actively collaborating in this process.

UK combat-related pelvic junctional vascular injuries 2008–2011: Implications for future intervention

In a recent publication, 297 of 6450 (4.6%) military coalition deaths over ten years were reported to be due to junctional bleeding. The authors suggested that some of these deaths could have been avoided with a junctional haemorrhage control device.Prospectively collected data on all injuries sustained in Afghanistan by UK military personnel from 1 August 2008 to 31 July 2011 period were reviewed, using the UK Joint Theatre Trauma Registry. All fatalities with significant pelvic injuries were identified and analysed, and the cause of death established to assess the potential role for a junctional haemorrhage control device.Significant upper thigh, groin or pelvic injuries were recorded in 124 casualties, of which 93 died. Of these the pelvic injury was the cause of death in 37, but only 1 casualty with potentially survivable injuries was identified where death was due to a vascular injury below the inguinal ligament, not controlled by a CAT. This represents <1% of all deaths in this period, a lower figure than previously published. We further identified 32 casualties where the cause of death was due to a vascular injury between the aortic bifurcation and the inguinal ligament. Eight of these survived to a medical facility but subsequently died of their wounds. These represent a subset in which vascular control proximal to the inguinal ligament could have altered the outcome.Some potentially survivable deaths due to exsanguination may be amenable to proximal vascular control. Our study does not substantiate previous conclusions that this can be achieved through use of a groin junctional tourniquet. We believe there may be a role for more proximal vascular control of pelvic bleeding, and this merits further research.