O Bouamra

The value of traditional vital signs, shock index, and age-based markers in predicting trauma mortality.

BACKGROUND Systolic blood pressure (SBP), heart rate (HR), and respiratory rate are poor predictors of trauma outcome. We postulate that HR/SBP (shock index [SI]) and novel new markers SI × age (SIA), SBP / age (BPAI), maximum HR (220 − age) − HR (minpulse [MP]), and HR / maximum HR (pulse max index [PMI]) are better predictors of 48-hour mortality compared with traditional vital signs. METHODS Data were extracted from the Trauma Audit and Research Network database. Exclusions included any head or spine injury and prehospital intubation or cardiac arrest. Area under receiver operator characteristic curve (AUROC) was determined for 48-hour mortality for all variables and age. A threshold for each marker was derived using the specificity (rule-in) cutoffs at both 90% and 95% from the receiver operator characteristic curve. Positive likelihood ratios were described for each marker’s derived threshold. RESULTS Vital signs, markers, and age were all significantly associated with 48-hour mortality (p < 0.001). HR, SBP, and respiratory rate fared worst overall (AUROC = 0.69, 0.66, and 0.66, respectively). SIA, MP, PMI, BPAI, and SI were significantly (p < 0.05) better than age at predicting 48-hour mortality (AUROC = 0.79, 0.77, 0.77, 0.74, 0.73, and 0.68, respectively; AUROC for age = 0.68). Thresholds derived for these five markers were values 55 or greater, 44 or less, 70% or greater, 1.5 or less, and 0.9 or greater, respectively, each with a specificity of 95% for 48-hour mortality (positive likelihood ratios were 8.4, 6.1, 6.7, 6.6, and 7.5, respectively). The likelihood of death in 48 hours was 8.4 times more likely if SIA was greater than 55 than if it was lower. CONCLUSION Older age seems to be significantly associated with early mortality. Newer markers, especially those combining traditional vital signs with age (SIA, BPAI, MP, and PMI), may contribute to better trauma triage of patients with blunt injuries than traditional vital signs. LEVEL OF EVIDENCE Prognostic/epidemiologic study, level III.

Lack of change in trauma care in England and Wales since 1994

Abstract: To demonstrate trends in trauma care in England and Wales from 1989 to 2000. Study population: Database of the Trauma Audit and Research Network that includes hospital patients admitted for three days or more, those who died, were transferred or admitted to an intensive care or high dependency area. Method: To demonstrate trends in outcome, severity adjusted odds of death per year of admission to hospital were calculated for all hospitals (n=99) and 20 hospitals who had participated since 1989 (adjustments are for Injury Severity Score, age, and Revised Trauma Score). The grade of doctor initially seeing the injured patient in accident and emergency and median prehospital times per year of admission were calculated to demonstrate trends in the process of care. Trend analyses were carried out using simple linear regression (odds ratio versus year). Results: The analysis shows a significant reduction in the severity adjusted odds of death of 3% per year over the 1989–2000 time period (p=0.001). During the period 1989–1994 the odds of death declined most steeply (on average 6% per year p=0.004). Between 1994 to 2000 no significant change occurred (p=0.35). This pattern was mirrored by the 20 permanent members where the odds of death also declined more steeply over the 1989–1994 period. The percentage of severely injured patients (ISS >15) seen by a consultant increased from 29 to 40 from 1989–1994 but has remained static subsequently. Median prehospital times for severely injured patients have not changed significantly since 1994 (51 to 45 minutes). Conclusion: Most of the case fatality reduction for trauma patients reaching hospital over the 1989–2000 time period occurred before 1995 when there was most marked change in the initial care of severely injured patients.

The effect of specialist neurosciences care on outcome in adult severe head injury: a cohort study.

BackgroundHead injury is the leading cause of death in trauma. UK national guidelines have recommended that all patients with severe head injury (SHI) should be treated in neuroscience centers. The aim of this study was to investigate the effect of specialist neuroscience care on mortality after SHI. MethodsWe conducted a cohort study using prospectively recorded data from the largest European trauma registry, for adult patients presenting with blunt trauma between 2003 and 2009. Mortality and unadjusted odds of death were compared for patients with SHI treated in neuroscience units (NSU) versus nonspecialist centers. To control for confounding, odds of death associated with non-NSU care were calculated using propensity score-adjusted multivariate logistic regression (explanatory covariates: age, Glasgow Coma Score, Injury Severity Score, treatment center). Sensitivity analyses were performed to study possible bias arising from selective enrollment, from loss to follow-up, and from hidden confounders. Results5411 patients were identified with SHI between 2003 and 2009, with 1485 (27.4%) receiving treatment entirely in non-NSU centers. SHI management in a non-NSU was associated with a 11% increase in crude mortality (P<0.001) and 1.72-fold (95% confidence interval: 1.52-1.96) increase in odds of death. The case mix adjusted odds of death for patients treated in a non-NSU unit with SHI was 1.85 (95% confidence interval: 1.57-2.19). These results were not significantly changed in sensitivity analyses examining selective enrollment or loss to follow-up, and were robust to potential bias from unmeasured confounders. ConclusionsOur data support current national guidelines and suggest that increasing transfer rates to NSUs represents an important strategy in improving outcomes in patients with SHI.BACKGROUNDnIsoflurane exposure can protect the mammalian brain from subsequent insults such as ischemic stroke. However, this protective preconditioning effect is sexually dimorphic, with isoflurane preconditioning decreasing male while exacerbating female brain damage in a mouse model of cerebral ischemia. Emerging evidence suggests that innate cell sex is an important factor in cell death, with brain cells having sex-specific sensitivities to different insults. We used an in vitro model of isoflurane preconditioning and ischemia to test the hypothesis that isoflurane preconditioning protects male astrocytes while having no effect or even a deleterious effect in female astrocytes after subsequent oxygen and glucose deprivation (OGD).nnnMETHODSnSex-segregated astrocyte cultures derived from postnatal day 0 to 1 mice were allowed to reach confluency before being exposed to either 0% (sham preconditioning) or 3% isoflurane preconditioning for 2 hours. Cultures were then returned to normal growth conditions for 22 hours before undergoing 10 hours of OGD. Twenty-four hours after OGD, cell viability was quantified using a lactate dehydrogenase assay.nnnRESULTSnIsoflurane preconditioning increased cell survival after OGD compared with sham preconditioning independent of innate cell sex.nnnCONCLUSIONnMore studies are needed to determine how cell type and cell sex may impact on anesthetic preconditioning and subsequent ischemic outcomes in the brain.

The epidemiology of and outcome from pancreatoduodenal trauma in the UK, 1989-2013

INTRODUCTIONnPancreatoduodenal (PD) injury is an uncommon but serious complication of blunt and penetrating trauma, associated with high mortality. The aim of this study was to assess the incidence, mechanisms of injury, initial operation rates and outcome of patients who sustained PD trauma in the UK from a large trauma registry, over the period 1989-2013.nnnMETHODSnThe Trauma Audit and Research Network database was searched for details of any patient with blunt or penetrating trauma to the pancreas, duodenum or both.nnnRESULTSnOf 356,534 trauma cases, 1,155 (0.32%) sustained PD trauma. The median patient age was 27 years for blunt trauma and 27.5 years for penetrating trauma. The male-to-female ratio was 2.5:1. Blunt trauma was the most common type of injury seen, with a ratio of blunt-to-penetrating PD injury ratio of 3.6:1. Road traffic collision was the most common mechanism of injury, accounting for 673 cases (58.3%). The median injury severity score (ISS) was 25 (IQR: 14-35) for blunt trauma and 14 (IQR: 9-18) for penetrating trauma. The mortality rate for blunt PD trauma was 17.6%; it was 12.2% for penetrating PD trauma. Variables predicting mortality after pancreatic trauma were increasing age, ISS, haemodynamic compromise and not having undergone an operation.nnnCONCLUSIONSnIsolated pancreatic injuries are uncommon; most coexist with other injuries. In the UK, a high proportion of cases are due to blunt trauma, which differs from US and South African series. Mortality is high in the UK but comparison with other surgical series is difficult because of selection bias in their datasets.

Comparison of two prognostic models in trauma outcome

The Trauma Audit and Research Network (TARN) in the UK publicly reports hospital performance in the management of trauma. The TARN risk adjustment model uses a fractional polynomial transformation of the Injury Severity Score (ISS) as the measure of anatomical injury severity. The Trauma Mortality Prediction Model (TMPM) is an alternative to ISS; this study compared the anatomical injury components of the TARN model with the TMPM.

EARLY WHOLE BODY VERSUS FOCUSED COMPUTED TOMOGRAPHY IMAGING FOLLOWING MAJOR TRAUMA: EXISTING EVIDENCE AND ANALYSIS OF 10 YEARS OF TARN DATA

Objectives & Background Whole Body Computed Tomography (WBCT) scanning is considered to be the chief imaging modality for patients with major trauma. There is growing evidence that the rate of survival is higher for patients undergoing early WBCT by facilitating rapid and accurate anatomical characterisation of potentially life-threatening injuries. There remains ongoing controversy whether this outweighs the potential risks from high-dose ionising radiation. Methods Data from the Trauma Audit and Research Network (TARN) trauma registry was analysed for all patients presenting from January 2005 to July 2014 inclusive aged 16 years or more admitted directly to hospital Emergency Departments (ED) with suspected severe blunt polytrauma. Survival was compared between two groups: (1) patients who underwent WBCT scans, and (2) those who underwent a focused CT (“non-WBCT”) scanning approach within the first four hours of arrival at the ED. Results 14,598 (23·2%) of 62,942 eligible cases underwent WBCT directly from the ED within four hours of arrival. The calculated crude survival rate for the WBCT group was 89·2%, compared to 88·9% in the non-WBCT group (p=0·260). The results of multivariate regression analysis, taking account of all possible confounders, demonstrated a trend towards improved survival in the WBCT scan group, with an OR=1·080 (95% CI 0·986–1·183) compared to the non-WBCT group (p=0·098). Conclusion The results of our investigation demonstrate a trend towards improved survival for adult patients with suspected severe blunt polytrauma undergoing WBCT scanning early in their management in the ED. Our analysis of the largest series of trauma cases investigating WBCT so far is the first to take account of all possible confounding factors including centre effect – often a major limitation for generalisability in previous studies of this kind. The existing evidence for the use of WBCT during the management of major trauma is also discussed in the context of these new results. Figure 1 Figure 2

The effect of an organized trauma system on mortality in major trauma involving serious head injury: A comparison of the United Kingdom and Victoria, Australia

Objective:To compare outcomes following major trauma involving serious head injury managed in an inclusive trauma system (Victoria, Australia) and a setting where rationalization of trauma services is absent (England/Wales). Background:The introduction of regionalized trauma systems has the potential to reduce preventable deaths, but their uptake has been slow around the world. Improved understanding of the benefits and limitations of different systems of trauma care requires comparison across systems. Methods:Mortality outcomes following major trauma involving serious head injury managed in the 2 settings were compared using multivariate logistic regression. Data pertaining to the period July 2001 to June 2006 (inclusive) were extracted from the Trauma Audit and Research Network (TARN) in the United Kingdom and the Victorian State Trauma Registry (VSTR) in Australia. Results:A total of 4064 (VSTR) and 6024 (TARN) cases were provided for analysis. The odds of death for TARN cases were significantly higher than those for VSTR cases [odds ratio = 2.15, 95% confidence interval = 1.95–2.37]. After adjusting for age, gender, cause of injury, head injury severity, Glasgow Coma Scale score, and Injury Severity Score, TARN cases remained at elevated odds of death (3.22; 95% confidence interval = 2.84–3.65) compared with VSTR cases. Conclusions:Management of the severely injured patient with an associated head injury in England and Wales, where an organized trauma system is absent, was associated with increased risk-adjusted mortality compared with management of these patients in the inclusive trauma system of Victoria, Australia. This study provides further evidence to support efforts to implement such systems.

The effect of specialist neurosciences care on outcome in adult severe head injury: A cohort study

BackgroundHead injury is the leading cause of death in trauma. UK national guidelines have recommended that all patients with severe head injury (SHI) should be treated in neuroscience centers. The aim of this study was to investigate the effect of specialist neuroscience care on mortality after SHI. MethodsWe conducted a cohort study using prospectively recorded data from the largest European trauma registry, for adult patients presenting with blunt trauma between 2003 and 2009. Mortality and unadjusted odds of death were compared for patients with SHI treated in neuroscience units (NSU) versus nonspecialist centers. To control for confounding, odds of death associated with non-NSU care were calculated using propensity score-adjusted multivariate logistic regression (explanatory covariates: age, Glasgow Coma Score, Injury Severity Score, treatment center). Sensitivity analyses were performed to study possible bias arising from selective enrollment, from loss to follow-up, and from hidden confounders. Results5411 patients were identified with SHI between 2003 and 2009, with 1485 (27.4%) receiving treatment entirely in non-NSU centers. SHI management in a non-NSU was associated with a 11% increase in crude mortality (P<0.001) and 1.72-fold (95% confidence interval: 1.52-1.96) increase in odds of death. The case mix adjusted odds of death for patients treated in a non-NSU unit with SHI was 1.85 (95% confidence interval: 1.57-2.19). These results were not significantly changed in sensitivity analyses examining selective enrollment or loss to follow-up, and were robust to potential bias from unmeasured confounders. ConclusionsOur data support current national guidelines and suggest that increasing transfer rates to NSUs represents an important strategy in improving outcomes in patients with SHI.BACKGROUNDnIsoflurane exposure can protect the mammalian brain from subsequent insults such as ischemic stroke. However, this protective preconditioning effect is sexually dimorphic, with isoflurane preconditioning decreasing male while exacerbating female brain damage in a mouse model of cerebral ischemia. Emerging evidence suggests that innate cell sex is an important factor in cell death, with brain cells having sex-specific sensitivities to different insults. We used an in vitro model of isoflurane preconditioning and ischemia to test the hypothesis that isoflurane preconditioning protects male astrocytes while having no effect or even a deleterious effect in female astrocytes after subsequent oxygen and glucose deprivation (OGD).nnnMETHODSnSex-segregated astrocyte cultures derived from postnatal day 0 to 1 mice were allowed to reach confluency before being exposed to either 0% (sham preconditioning) or 3% isoflurane preconditioning for 2 hours. Cultures were then returned to normal growth conditions for 22 hours before undergoing 10 hours of OGD. Twenty-four hours after OGD, cell viability was quantified using a lactate dehydrogenase assay.nnnRESULTSnIsoflurane preconditioning increased cell survival after OGD compared with sham preconditioning independent of innate cell sex.nnnCONCLUSIONnMore studies are needed to determine how cell type and cell sex may impact on anesthetic preconditioning and subsequent ischemic outcomes in the brain.

015 Temporal trends in head injury outcomes from 2003 to 2010 in England and Wales, and the effect of specialist neurosciences care: a Cohort Study

Objectives and Backgrounds Head injury (HI) is the leading cause of death in trauma, and case fatality rates after blunt HI did not improve in England and Wales between 1994 and 2003. Subsequent national guidelines have recommended that all severe HIs should be treated in neuroscience units (NSUs). The aim of this study was to investigate case fatality trends in HI since 2003 and establish the effect of specialist neuroscience care on mortality after severe HI. Methods We conducted a cohort study using prospectively recorded data from the TARN trauma registry for adult patients presenting with blunt trauma between 2003 and 2009. Temporal trends in log odds of death adjusted for case mix were examined for patients with and without HI. Rates of transfer and mortality were compared for patients with severe HI treated in NSUs vs non-specialist centres. Propensity score adjusted multivariate logistic regression was then used to calculate case mix adjusted odds of death associated with non-NSU care. Results Since 2003 there was an average 12% reduction in case mix adjusted log odds of death per annum in patients with HI (n=15u2008173), with a similar but smaller trend in non-HI trauma mortality (n=48u2008681). During the study period the proportion of patients with HI treated entirely in non-NSUs decreased from 31% to 19%, (p<0.01). Severe HI management in non-NSUs was associated with a 11% increase in crude mortality (p<0.01) and a case mix adjusted 1.85 (95% CI 1.57 to 2.19) fold increase in odds of death. Conclusions The reduction in log odds of death following HI since 2003 is consistent with increased levels of treatment in NSUs, or better management following the introduction of national HI guidelines. Our data suggests that increasing transfer rates to NSUs represents an important strategy in further improving outcomes in severe HI.