Omar Bouamra

Trends in head injury outcome from 1989 to 2003 and the effect of neurosurgical care: An observational study

BACKGROUND Case fatality rates after all types of blunt injury have not improved since 1994 in England and Wales, possibly because not all patients with severe head injury are treated in a neurosurgical centre. Our aims were to investigate the case fatality trends in major trauma patients with and without head injury, and to establish the effect of neurosurgical care on mortality after severe head injury. METHODS We analysed prospectively collected data from the Trauma Audit and Research Network database for patients presenting between 1989 and 2003. Mortality and odds of death adjusted for case mix were compared for patients with and without head injury, and for those treated in a neurosurgical versus a non-neurosurgical centre. FINDINGS Patients with head injury (n=22,216) had a ten-fold higher mortality and showed less improvement in the adjusted odds of death since 1989 than did patients without head injury (n=154,231). 2305 (33%) of patients with severe head injury (presenting between 1996 and 2003) were treated only in non-neurosurgical centres; such treatment was associated with a 26% increase in mortality and a 2.15-fold increase (95% CI 1.77-2.60) in the odds of death adjusted for case mix compared with patients treated at a neurosurgical centre. INTERPRETATION Since 1989 trauma system changes in England and Wales have delivered greater benefit to patients without head injury. Our data lend support to current guidelines, suggesting that treatment in a neurosurgical centre represents an important strategy in the management of severe head injury.

Vital signs and estimated blood loss in patients with major trauma: testing the validity of the ATLS classification of hypovolaemic shock.

AIM The Advanced Trauma Life Support (ATLS) system classifies the severity of shock. The aim of this study is to test the validity of this classification. METHODS Admission physiology, injury and outcome variables from adult injured patients presenting to hospitals in England and Wales between 1989 and 2007 and stored on the Trauma Audit and Research Network (TARN) database, were studied. For each patient, the blood loss was estimated and patients were divided into four groups based on the estimated blood loss corresponding to the ATLS classes of shock. The median and interquartile ranges (IQR) of the heart rate (HR) systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Score (GCS) were calculated for each group. RESULTS The median HR rose from 82 beats per minute (BPM) in estimated class 1 shock to 95 BPM in estimated class 4 shock. The median SBP fell from 135 mm Hg to 120 mm Hg. There was no significant change in RR or GCS. CONCLUSION With increasing estimated blood loss there is a trend to increasing heart rate and a reduction in SBP but not to the degree suggested by the ATLS classification of shock.

A major trauma centre is a specialty hospital not a hospital of specialties

High estimates of preventable death rates have renewed the impetus for national regionalization of trauma care. Institution of a specialist multidisciplinary trauma service and performance improvement programme was hypothesized to have resulted in improved outcomes for severely injured patients.

Systolic blood pressure below 110 mmHg is associated with increased mortality in penetrating major trauma patients: Multicentre cohort study

INTRODUCTION Non-invasive systolic blood pressure (SBP) measurement is often used in triaging trauma patients. Traditionally, SBP< 90 mm Hg has represented the threshold for hypotension, but recent studies have suggested redefining hypotension as SBP < 110 mm Hg. This study aims to examine the association of SBP with mortality in blunt trauma patients. METHODS This is an analysis of prospectively recorded data from adult (≥ 16 years) blunt trauma patients. Included patients presented to hospitals belonging to the Trauma Audit and Research Network (TARN) between 2000 and 2009. The primary outcome was the association of SBP and mortality rates at 30 days. Multivariate logistic regression models were used to adjust for the influence of age, gender, Injury Severity Score (ISS) and Glasgow Coma Score (GCS) on mortality. RESULTS 47,927 eligible patients presented to TARN hospitals during the study period. Sample demographics were: median age: 51.1 years (IQR=32.8-67.4); male 60% (n=28,694); median ISS 9 (IQR=8-10); median GCS 15 (IQR=15-15); and median SBP 135 mm Hg (IQR=120-152). We identified SBP< 110 mm Hg as a cut off for hypotension, where a significant increase in mortality was observed. Mortality rates doubled at < 100 mm Hg, tripled at < 90 mm Hg and were 5- to 6-fold at < 70 mm Hg, irrespective of age. CONCLUSION We recommend triaging adult blunt trauma patients with a SBP< 110 mm Hg to resuscitation areas within dedicated trauma units for close monitoring and appropriate management.

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.

Testing the validity of the ATLS classification of hypovolaemic shock

AIM The Advanced Trauma Life Support system classifies the severity of shock. The aim of this study is to test the validity of this classification. METHODS Admission physiology, injury and outcome variables from adult injured patients presenting to hospitals in England and Wales between 1989 and 2007 and stored on the Trauma Audit and Research Network (TARN) database, were studied. Patients were divided into groups representing the four ATLS classes of shock, based on heart rate (HR) systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Score (GCS). The relationships between variables were examined by classifying the cohort by each recorded variable in turn and deriving the median and interquartile range (IQR) of the remaining three variables. Patients with penetrating trauma and major injuries were examined in sub-group analyses. RESULTS In blunt trauma patients grouped by HR, the median SBP decreased from 128 mmHg in patients with HR<100 BPM to 114 mmHg in those with HR>140 BPM. The median RR increased from 18 to 22 bpm and the GCS reduced from 15 to 14. The median HR in hypotensive patients was 88 BPM compared to 83 BPM in normotensive patients and the RR was the same. When grouped by RR, the HR increased with increasing RR but there were no changes in SBP. CONCLUSION In trauma patients there is an inter-relationship between derangements of HR, SBP, RR and GCS but not to the same degree as that suggested by the ATLS classification of shock.

Predicting early death in patients with traumatic bleeding: development and validation of prognostic model

Objective To develop and validate a prognostic model for early death in patients with traumatic bleeding. Design Multivariable logistic regression of a large international cohort of trauma patients. Setting 274 hospitals in 40 high, medium, and low income countries Participants Prognostic model development: 20 127 trauma patients with, or at risk of, significant bleeding, within 8 hours of injury in the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2) trial. External validation: 14 220 selected trauma patients from the Trauma Audit and Research Network (TARN), which included mainly patients from the UK. Outcomes In-hospital death within 4 weeks of injury. Results 3076 (15%) patients died in the CRASH-2 trial and 1765 (12%) in the TARN dataset. Glasgow coma score, age, and systolic blood pressure were the strongest predictors of mortality. Other predictors included in the final model were geographical region (low, middle, or high income country), heart rate, time since injury, and type of injury. Discrimination and calibration were satisfactory, with C statistics above 0.80 in both CRASH-2 and TARN. A simple chart was constructed to readily provide the probability of death at the point of care, and a web based calculator is available for a more detailed risk assessment (http://crash2.lshtm.ac.uk). Conclusions This prognostic model can be used to obtain valid predictions of mortality in patients with traumatic bleeding, assisting in triage and potentially shortening the time to diagnostic and lifesaving procedures (such as imaging, surgery, and tranexamic acid). Age is an important prognostic factor, and this is of particular relevance in high income countries with an aging trauma population.

Intracranial bleeding in patients with traumatic brain injury: A prognostic study

BackgroundIntracranial bleeding (IB) is a common and serious consequence of traumatic brain injury (TBI). IB can be classified according to the location into: epidural haemorrhage (EDH) subdural haemorrhage (SDH) intraparenchymal haemorrhage (IPH) and subarachnoid haemorrhage (SAH). Studies involving repeated CT scanning of TBI patients have found that IB can develop or expand in the 48 hours after injury. If IB enlarges after hospital admission and larger bleeds have a worse prognosis, this would provide a therapeutic rationale for treatments to prevent increase in the extent of bleeding. We analysed data from the Trauma Audit & Research Network (TARN), a large European trauma registry, to evaluate the association between the size of IB and mortality in patients with TBI.MethodsWe analysed 13,962 patients presenting to TARN participating hospitals between 2001 and 2008 with a Glasgow Coma Score (GCS) less than 15 at presentation or any head injury with Abbreviated Injury Scale (AIS) severity code 3 and above. The extent of intracranial bleeding was determined by the AIS code. Potential confounders were age, presenting Glasgow Coma Score, mechanism of injury, presence and nature of other brain injuries, and presence of extra-cranial injuries. The outcomes were in-hospital mortality and haematoma evacuation. We conducted a multivariable logistic regression analysis to evaluate the independent effect of large and small size of IB, in comparison with no bleeding, on patient outcomes. We also conducted a multivariable logistic regression analysis to assess the independent effect on mortality of large IB in comparison with small IB.ResultsAlmost 46% of patients had at some type of IB. Subdural haemorrhages were present in 30% of the patients, with epidural and intraparenchymal present in approximately 22% each. After adjusting for potential confounders, we found that large IB, wherever located, was associated with increased mortality in comparison with no bleeding. We also found that large IB was associated with an increased risk of mortality in comparison with small IB. The odds ratio for mortality for large SDH, IPH and EDH, in comparison with small bleeds, were: 3.41 (95% CI: 2.68-4.33), 3.47 (95% CI: 2.26-5.33) and 2.86 (95% CI: 1.86-4.38) respectively.ConclusionLarge EDH, SDH and IPH are associated with a substantially higher probability of hospital mortality in comparison with small IB. However, the limitations of our data, such as the large proportion of missing data and lack of data on other confounding factors, such as localization of the bleeding, make the results of this report only explanatory. Future studies should also evaluate the effect of IB size on functional outcomes.

Epidemiology and predictors of cervical spine injury in adult major trauma patients: a multicenter cohort study

BACKGROUND: Patients with cervical spine injuries are a high-risk group, with the highest reported early mortality rate in spinal trauma. METHODS: This cohort study investigated predictors for cervical spine injury in adult (≥ 16 years) major trauma patients using prospectively collected data of the Trauma Audit and Research Network from 1988 to 2009. Univariate and multivariate logistic regression analyses were used to determine predictors for cervical fractures/dislocations or cord injury. RESULTS: A total of 250,584 patients were analyzed. Median age was 47.2 years (interquartile range, 29.8–66.0) and Injury Severity Score 9 (interquartile range, 4–11); 60.2% were male. Six thousand eight hundred two patients (2.3%) sustained cervical fractures/dislocations alone. Two thousand sixty-nine (0.8%) sustained cervical cord injury with/without fractures/dislocations; 39.9% of fracture/dislocation and 25.8% of cord injury patients suffered injuries to other body regions. Age ≥65 years (odds ratio [OR], 1.45–1.92), males (females OR, 0.91; 95% CI, 0.86–0.96), Glasgow Coma Scale (GCS) score <15 (OR, 1.26–1.30), LeFort facial fractures (OR, 1.29; 95% confidence interval [CI], 1.05–1.59), sports injuries (OR, 3.51; 95% CI, 2.87–4.31), road traffic collisions (OR, 3.24; 95% CI, 3.01–3.49), and falls >2 m (OR, 2.74; 95% CI, 2.53–2.97) were predictive for fractures/dislocations. Age <35 years (OR, 1.25–1.72), males (females OR, 0.59; 95% CI, 0.53–0.65), GCS score <15 (OR, 1.35–1.85), systolic blood pressure <110 mm Hg (OR, 1.16; 95% CI, 1.02–1.31), sports injuries (OR, 4.42; 95% CI, 3.28–5.95), road traffic collisions (OR, 2.58; 95% CI, 2.26–2.94), and falls >2 m (OR, 2.24; 95% CI, 1.94–2.58) were predictors for cord injury. CONCLUSIONS: 3.5% of patients suffered cervical spine injury. Patients with a lowered GCS or systolic blood pressure, severe facial fractures, dangerous injury mechanism, male gender, and/or age ≥35 years are at increased risk. Contrary to common belief, head injury was not predictive for cervical spine involvement. LEVEL OF EVIDENCE: II.

Paediatric trauma: injury pattern and mortality in the UK

Objective: Trauma accounts for a large proportion of childhood deaths. No data exist about injury patterns within paediatric trauma in the UK. Identification of specific high-risk injury patterns may lead to improved care and outcome. Methods: Data from 24 218 paediatric trauma cases recorded by the Trauma Audit and Research Network (TARN) from 1990 to 2005 were analysed. Main injury, injury patterns and outcome were analysed. Mortality at 93 days’ post-injury was the major outcome measure. Results: Limb injuries occurred in 65.0% of patients. In infants 81.4% of head injuries were isolated, compared with 46.5% in 11–15-year-old children. Thoracic injuries were associated with other injuries in 68.4%. The overall mortality rate was 3.7% (n = 893). Mortality decreased from 4.2% to 3.1%; this was most evident in non-isolated head injuries. It was low in isolated injuries: 1.5% (n = 293). In children aged 1–15 years the highest mortalities occurred in multiple injuries including head/thoracic (47.7%) and head/abdominal injuries (49.9%). Having a Glasgow Coma Scale of <15 on presentation to hospital was associated with a mortality of 16%. Conclusions: Differences in injury patterns and mortality exist between different age groups and high-risk injury patterns can be identified. With increasing age, a decline in the proportion of children with head injury and an increase in the proportion with limb injury were observed. This information is useful for directing ongoing care of severely injured children. Future analyses of the TARN database may help to evaluate the management of high-risk children and to identify the most effective care.