[Tree collisions in road traffic accidents - mechanism and pattern of injury]

INTRODUCTION

In Germany, the county of Mecklenburg-Vorpommern has got the highest frequency of traffic accidents. 42 % of all deadly injured car accident victims in Mecklenburg-Vorpommern sustained a tree collision. Aim of this study was to analyze tree collisions regarding typical pattern and severity of injury.

METHODS

During an on-going prospective, non-interventional accident survey within a defined area of the county of Mecklenburg-Vorpommern tree collisions with minimum one victim sustaining a Maximum Abbreviated Injury Scale of 1-6 injury were analyzed.

RESULTS

In between January 2001 and June 2004 287 accidents were documented. 19 % (54) were tree collisions. 81 % of drivers were male. 36 of 54 tree collisions (67 %) occurred on straight roadways. The mean ISS was 31.3 (SD +/- 29.8), 30 % (23) of the passengers died. 70 of 78 individuals sustained more than one injury. With that, the combination of head- and chest trauma was most frequent and associated with the highest injury severity.

DISCUSSION

Especially tree collisions lead to severe trauma. Interestingly, most accidents did occur on straight roadways.

Calcaneal fractures in occupants involved in severe frontal motor vehicle crashes

The calcaneous is the largest tarsal bone in the foot and plays an important role in walking and running. Motor vehicle crashes and falls from elevation have been associated with calcaneal fractures. Although not life-threatening, these injuries may result in permanent disability. This study used the Crash Injury Research and Engineering Network (CIREN) database to describe calcaneal fractures and concomitant lower extremity skeletal injury patterns for occupants involved in motor vehicle crashes. Sixty-three drivers and 7 front row passengers with calcaneal fractures were identified in the CIREN database during 1997-2005. Almost all these occupants were involved in severe (based on the delta V and vehicle crush) frontal or off-set frontal crashes with toe pan intrusion. Eighty-four percent of the calcaneal fractures were intra-articular or partially articular. Overall, 93% of occupants also had injury to other body regions with 84% having other lower extremity fractures. One year after the crash, most occupants had not returned to their prior level of physical functioning. Surgically managing patients with calcaneal fractures for an optimal outcome remains a challenge for orthopedic surgeons. Because lower extremity injuries, including calcaneal fractures, may cause permanent disability, it is important to prevent these injuries through structural improvements in motor vehicle design.

Validation of a Relative Head Injury Severity Scale for Pediatric Trauma

BACKGROUND

Brain injury is the most important independent predictor of mortality and morbidity in pediatric trauma. The Glasgow Coma Score (GCS) is the commonly used clinical instrument to assess brain injury. However, the GCS or one of its components is often not applicable in children under a certain age or cannot be computed reliably because of the patient's condition or the circumstances surrounding resuscitation efforts. This limits its usefulness in statistical models of trauma outcomes, which rely on complete data collection and entry into trauma registries. This study provides evidence validating use of a relative head injury severity scale (RHISS) derived from available International Classification of Diseases, 9th Revision (ICD-9) diagnosis codes to stratify degree of head injury.

METHODS

The patient population was derived from the National Pediatric Trauma Registry (NPTR;1994-2001). Survival Risk Ratios (SRRs) were computed for each head injury ICD-9 code. ICD-9 diagnosis codes related to head injury were then assigned to a RHISS category based on duration of loss of consciousness, location of skull fracture, or both: 0 = none; 1 = mild; 2 = moderate, or 3 = severe head injury. Analysis of variance compared mean SRRs across RHISS categories. Each patient was then assigned to a RHISS category based on their single worst ICD-9 head injury code. Logistic regression analysis was used to predict mortality based on New Injury Severity Score (NISS), whether the patient had been intubated, RHISS, and the Abbreviated Injury Score (AIS) for head and neck injuries.

RESULTS

GCS score was missing for 96% of nonsurvivors in the NPTR. Mean SRRs differed significantly (p < 0.001) among ICD-9 codes assigned to each RHISS category, as follows (Mean +/- SD): RHISS (0) = 0.93 +/- 0.16; RHISS (1) = 0.89 +/- 0.22; RHISS (2) = 0.85 +/- 0.26; RHISS (3) = 0.55 +/- 0.35. Logistic regression identified RHISS as an independent significant predictor (p < 0.01) of mortality.

CONCLUSION

RHISS is a valid index of degree of head injury in the pediatric trauma population. Unlike GCS, RHISS is more likely to be available in trauma registries, and can be computed from administrative data. RHISS provides a feasible and valid method for quantifying the degree of brain injury in statistical models of pediatric trauma outcome.

Usefulness of the abbreviated injury score and the injury severity score in comparison to the Glasgow Coma Scale in predicting outcome after traumatic brain injury

BACKGROUND

Assessment of injury severity is important in the management of patients with brain trauma. We aimed to analyze the usefulness of the head abbreviated injury score (AIS), the injury severity score (ISS), and the Glasgow Coma Scale (GCS) as measures of injury severity and predictors of outcome after traumatic brain injury (TBI).

METHODS

Data were prospectively collected from 410 patients with TBI. AIS, ISS, and GCS were recorded at admission. Subjects' outcomes after TBI were measured using the Glasgow Outcome Scale (GOS-E) at 12 months postinjury. Uni- and multivariate analyses were performed.

RESULTS

Outcome information was obtained from 270 patients (66%). ISS was the best predictor of GOS-E (rs = -0.341, p < 0.001), followed by GCS score (rs = 0.227, p < 0.001), and head AIS (rs = -0.222, p < 0.001). When considered in combination, GCS score and ISS modestly improved the correlation with GOS-E (R = 0.335, p < 0.001). The combination of GCS score and head AIS had a similar effect (R = 0.275, p < 0.001). Correlations were stronger from patients <or=48 years old. We found comparable correlations between patients who suffered severe injuries (GCS <or=8) and those who suffered mild and moderate injuries (GCS >8).

CONCLUSIONS

GCS score, AIS, and ISS are weakly correlated with 12-month outcome. However, anatomic measures modestly outperform GCS as predictors of GOS-E. The combination of GCS and AIS/ISS correlate with outcome better than do any of the three measures alone. Results support the addition of anatomic measures such as AIS and ISS in clinical studies of TBI. Additionally, most of the variance in outcome is not accounted for by currently available measures of injury severity.

Effect of alcohol on Glasgow Coma Scale in head-injured patients

OBJECTIVE

Almost 50% of traumatic brain-injured (TBI) patients are alcohol intoxicated. The Glasgow Coma Scale (GCS) is frequently used to direct diagnostic and therapeutic decisions in these patients. It is commonly assumed that alcohol intoxication reduces GCS, thus limiting its utility in intoxicated patients. The purpose of this study was to test the hypothesis that the presence of blood alcohol has a clinically significant impact on GCS in TBI patients.

METHODS

The National Trauma Data Bank of the American College of Surgeons was queried (1994-2003). Patients 18 to 45 years of age with blunt injury mechanism, whose GCS in the emergency department, survival status, anatomic severity of TBI (Head Abbreviated Injury Score [AIS]), and blood alcohol testing status were known, were included. GCS of patients who tested positive for alcohol (n = 55,732) was compared with GCS of patients who tested negative (n = 53,197), stratified by head AIS.

RESULTS

Groups were similar in age (31 +/- 8 vs. 30 +/- 8 years), Injury Severity Score (ISS; 12 +/- 11 vs. 12 +/- 11), systolic blood pressure in the ED (131 +/- 25 vs. 134 +/- 25 mm Hg), TRISS (Trauma Injury Severity Score; probability of survival (94% +/- 16% vs. 95% +/- 15%), and actual survival (96% vs. 96%). When stratified by anatomic severity of TBI, the presence of alcohol did not lower GCS by more than 1 point in any head AIS group (GCS in alcohol-positive vs. alcohol-negative patients; AIS 1 = 13.9 +/- 2.8 vs. 14.3 +/- 2.3; AIS 2 = 13.4 +/- 3.2 vs. 14.1 +/- 2.4; AIS 3 = 11.1 +/- 4.7 vs. 11.6 +/- 4.6; AIS 4 = 9.8 +/- 4.9 vs. 10.4 +/- 4.9; AIS 5 = 5.5 +/- 3.8 vs. 5.9 +/- 4.1, AIS 6: 3.4 +/- 1.1 vs. 3.8 +/- 2.8).

CONCLUSION

Alcohol use does not result in a clinically significant reduction in GCS in trauma patients. Attributing low GCS to alcohol intoxication in TBI patients may delay necessary diagnostic and therapeutic interventions.

Quality of hospital discharge data for injury prevention

OBJECTIVE

To examine the use of unspecified codes for the circumstances of injury for New Zealand public hospital discharges at a district health board (DHB) level.

METHODS

Hospital injury discharges for the period 2000-3 were examined. The use of the International Classification of Diseases unspecified categories was examined for mechanism of injury, activity and place of occurrence.

RESULTS

For all DHBs, the combined age-adjusted and mechanism-adjusted usage of unspecified mechanism codes was 7% and ranged from 3% to 11%. Most (57%) of these cases were unspecified falls. The comparable usage for activity was 39% and ranged from 17% to 52%, and for place of occurrence the respective figures were 23% and 7-36%. Only 50% of hospital discharges were completely specified in terms of mechanism of injury, activity and place of occurrence; this varied from 36% to 74% between DHBs. For several DHBs a significant degree of inconsistency was found in performance across mechanism, activity and place of occurrence coding.

CONCLUSIONS

Those DHBs with a high proportion of cases coded as unspecified would serve the prevention efforts of their communities better by making efforts to determine the cause of this situation and implement measures to reduce the problem.

Modeling Probability-Based Injury Severity Scores in Logistic Regression Models: The Logit Transformation Should Be Used

BACKGROUND

The International Classification of Disease Injury Severity Score (ICISS) and the Trauma Registry Abbreviated Injury Scale Score (TRAIS) are trauma injury severity scores based on probabilities of survival. They are widely used in logistic regression models as raw probability scores to predict the logit of mortality. The aim of this study was to evaluate whether these severity indicators would offer a more accurate prediction of mortality if they were used with a logit transformation.

METHODS

Analyses were based on 25,111 patients from the trauma registries of the four Level I trauma centers in the province of Quebec, Canada, abstracted between 1998 and 2005. The ICISS and TRAIS were calculated using survival proportions from the National Trauma Data Bank. The performance of the ICISS and TRAIS in their widely used form, proportions varying from 0 to 1, was compared with a logit transformation of the scores in logistic regression models predicting in-hospital mortality. Calibration was assessed with the Hosmer-Lemeshow statistic.

RESULTS

Neither the ICISS nor the TRAIS had a linear relation with the logit of mortality. A logit transformation of these scores led to a near-linear association and consequently improved model calibration. The Hosmer-Lemeshow statistic was 68 (35-192) and 69 (41-120) with the logit transformation compared with 272 (227-339) and 204 (166-266) with no transformation, for the ICISS and TRAIS, respectively.

CONCLUSIONS

In logistic regression models predicting mortality, the ICISS and TRAIS should be used with a logit transformation. This study has direct implications for improving the validity of analyses requiring control for injury severity case mix.

Early Unreamed Intramedullary Nailing of Femoral Fractures is Safe in Patients With Severe Thoracic Trauma

BACKGROUND

The timing of fixation of femoral fractures in multiply injured patients with severe thoracic trauma is discussed controversially. Some authors recommend damage control surgery, whereas other authors prefer early definitive treatment. The aim of our study was to investigate the effect of early definitive fixation of femoral fractures on outcomes in multiply injured patients with severe thoracic trauma.

METHODS

Between May 1, 1998 and December 31, 2004, 578 severely injured patients were admitted to our institution. Forty-five patients met the inclusion criteria for the study cohort (severe thoracic trauma and femoral fracture stabilized with unreamed intramedullary nailing [IMN] within the first 24 hours) and 107 patients were selected for the control cohort (severe thoracic trauma without any lower extremity fracture). Inclusion criteria for both cohorts were age 15 to 55 years with blunt trauma (e.g. motor vehicle collisions, falls) including severe thoracic trauma (Abbreviated Injury Scale [AIS] score >or=3) and Injury Severity Score (ISS) >or=18. For comparison between the cohorts data on patients status (Glasgow Coma Scale score at arrival, Revised Trauma Score, Trauma and Injury Severity Score survival prognosis, Simplified Acute Physiology Score II score), treatment (intubation rate, thoracic drainage, surgery), and outcomes (duration of intensive care unit stay and ventilation, rate of adult respiratory distress syndrome [ARDS], multiple organ failure syndrome [MOFS], and mortality) were selected from hospital databases. Dichotomous data were analyzed by chi test; continuous data were analyzed by Student's t test. Any values of p < 0.05 were considered significant for any test.

RESULTS

Both cohorts were comparable with regard to demographic data, ISS, AIS score in the thoracic region, and incidence and severity of brain injury. There was no difference in dependent parameters in both cohorts. Rates of ARDS, MOFS, and mortality were not negatively influenced by early unreamed IMN.

CONCLUSION

Early unreamed IMN of femoral fractures in multiply injured patients with severe thoracic trauma is a safe procedure and seems to be justified to achieve early definitive care.

Neck injury tolerance under inertial loads in side impacts

Neck injury remains a major issue in road safety. Current side impact dummies and side impact crashworthiness assessments do not assess the risk of neck injury. These assessments are limited by biofidelity and knowledge regarding neck injury criteria and tolerance levels in side impacts. Side impact tests with PMHS were performed at the Heidelberg University in the 1980s and 1990s to improve primarily the understanding of trunk dynamics, injury mechanisms and criteria. In order to contribute to the definition of human tolerances at neck level, this study presents an analysis of the head/neck biomechanical parameters that were measured in these tests and their relationship to neck injury severity. Data from 15 impact tests were analysed. Head accelerations, and neck forces and moments were calculated from 9-accelerometer array head data, X-rays and anthropometric data. Statistically significant relationships were observed between resultant head acceleration and neck force and neck injury severity. The average resultant head acceleration for AIS 2 neck injuries was 112 g, while resultant neck force was 4925 N and moment 241 Nm. The data compared well to other test data on cadavers and volunteers. It is hoped that the paper will assist in the understanding of neck injuries and the development of tolerance criteria.

Injuries caused by the attenuated energy projectile: the latest less lethal option

OBJECTIVES

To review the injuries resulting from the attenuated energy projectile (AEP) in patients who present to emergency departments.

METHOD

Review of case notes of patients presenting with injuries caused by the AEP after three episodes of serious civil disturbance in Northern Ireland from July to September 2005.

RESULTS

14 patients with 18 injuries were identified and included in the study. All patients were male, with an average age of 26.3 years. There were six injuries above the level of the clavicle, to the head, face or neck. There were three chest injuries, seven lower limb injuries and two upper limb injuries. There were no abdominal injuries. Seven patients required hospital admission. Five patients required surgical intervention. One patient required protective, elective intubation and one patient required the insertion of a chest drain.

DISCUSSION

Although the study numbers were small, 33.33% of injuries were to the head and neck and 16.67% of the injuries were to the chest. The AEP was introduced as a replacement for its predecessor, the L21A1 plastic baton round, because of a theoretical risk of serious or even life threatening head injury from this projectile in certain circumstances. However, in this first survey of its usage, 50% of the injuries presenting to hospital were to the face, neck, head or chest. This injury pattern was more in keeping with older plastic baton rounds than with the L21A1.

Long-Term Survival of Medicare Patients With Head Injury

BACKGROUND

An increasing number of older patients are being hospitalized with traumatic brain injury (TBI). Knowledge of their expected long-term survival may be useful in making clinical decisions.

METHODS

Patients age 65 or older admitted for the first time with head injury (ICD-9 800-804 or 850-854) during 1999 were identified in a complete national sample of fee-for-service Medicare hospitalization and denominator data. Cases were categorized by age, sex, maximum Abbreviated Injury Score (AISmax), and Charlson comorbidity score. Survival was determined at hospital discharge, and (using the denominator file) at 1, 6, 12, and 24 months after the initial hospital admission.

RESULTS

For all cases (n = 30,684), the hospital mortality was 14.3%, but was cumulatively 19.75%, 30.5%, 36.1%, and 44.9% at successive times up to 24 months. Long-term mortality was higher with increased age, comorbidity, or AISmax, and higher in men. These effects persisted with multivariate logistic regression analysis and were used to construct a simplified prediction score for clinical use.

CONCLUSIONS

The mortality for older patients with TBI is much higher than for an uninjured control population. The relative risk for death remains elevated after hospital discharge and for at least 2 years. Awareness of the expected prognosis may help family members and health care providers make appropriate clinical decisions during acute hospitalization.

Head-Injured Patients Who “Talk and Die”: The San Diego Perspective

BACKGROUND

Head-injured patients who "talk and die" are potentially salvageable, making their early identification important. This study uses a large, comprehensive database to explore risk factors for head-injured patients who deteriorate after their initial presentation.

METHODS

Patients with a head Abbreviated Injury Score (AIS) score of 3+ and a preadmission verbal Glasgow Coma Scale (GCS) score of 3+ were identified from our county trauma registry during a 16-year period. Survivors and nonsurvivors were compared with regard to demographics, initial clinical presentation, and various risk factors. Logistic regression was used to explore the impact of multiple factors on outcome, including the significance of a change in GCS score from field to arrival. In addition, patients were stratified by injury severity and hospital day of death to further define the relationship between outcome and multiple clinical variables.

RESULTS

A total of 7,443 patients were identified with head AIS 3+ and verbal GCS score 3+. Overall mortality was 6.1%. About one-third of deaths occurred on the first hospital day, with more than one-third occurring after hospital day 5. Logistic regression revealed an association between mortality and older age, more violent mechanisms of injury (fall, gunshot wound, pedestrian versus automobile), greater injury severity (higher head AIS and Injury Severity Score), lower GCS score, and hypotension. In addition, mortality was associated with a decrease in GCS score from field to arrival, the use of anticoagulants, and a diagnosis of pulmonary embolus. Two important groups of "talk-and-die" patients were identified. Early deaths occurred in younger patients with more critical extracranial injuries. Anticoagulant use was also an independent risk factor in these early deaths. Later deaths occurred in older patients with less significant extracranial injuries. Pulmonary embolus also appeared to be an important contributor to late mortality.

CONCLUSIONS

More severe injuries and use of anticoagulants are independent risk factors for early death in potentially salvageable traumatic brain injury patients, whereas older age and pulmonary embolus are associated with later deaths.

Differences in pain patterns for infected and noninfected patients with burn injuries

The management of pain is a primary issue in burn care. Patients hospitalized for burn injuries experience severe pain on a daily basis, immediately after the injury and during the healing of the burn wound. Our clinical experience is that the intensity of pain is increased by wound infection. The purpose of this study was to investigate retrospectively whether patients experience increased pain intensity in conjunction with wound infection. A total of 165 patients with burn injuries were included, 60 of whom were diagnosed with infection. The results of this study showed a significant increase in pain intensity in association with infection. An increase in pain is one of the factors to be considered among the many assessments, tests, and treatments for patients with burn injuries.

Kinematics of belted fatalities in frontal collisions: A new approach in deep studies of injury mechanisms

BACKGROUND

More than half of car crash fatalities are belted occupants, and the majority of these occur as a consequence of frontal crashes. In an earlier study of crash configuration characteristics, we have shown that 48% of fatalities occurred in frontal small overlap (SO) crashes in which less than 30% of the vehicle front was engaged. Only 23% of fatalities occurred in large overlap (LO) crashes engaging the drive train, similar to most barrier front crash testing procedures. The main purpose of this study was to analyze the characteristics of injury mechanisms and injuries in fatal SO and LO car crashes in Sweden.

METHOD

Retrospective examination and analysis of 61 fatally injured occupants from 53 car crashes within a sample area covering 40% of the population of Sweden was conducted.

RESULTS

A clear difference in injury mechanisms and injuries was found between SO and LO crashes. The major injury mechanisms in SO crashes are explained by an oblique torso movement and rotation toward the outboard side, which causes a high proportion of serious lateral chest and head injuries. In contrast, LO crashes were generally characterized by serious anterior chest injuries in elderly occupants (> or =60 years).

CONCLUSION

Current government and consumer barrier crash test procedures are not designed to estimate the performance of cars and restraint systems for the type of crashes which caused the majority of occupant fatalities in this data set.

An evaluation of the EuroNCAP crash test safety ratings in the real world

We investigated whether the rating obtained in the EuroNCAP test procedures correlates with injury protection to vehicle occupants in real crashes using data in the UK Cooperative Crash Injury Study (CCIS) database from 1996 to 2005. Multivariate Poisson regression models were developed, using the Abbreviated Injury Scale (AIS) score by body region as the dependent variable and the EuroNCAP score for that particular body region, seat belt use, mass ratio and Equivalent Test Speed (ETS) as independent variables. Our models identified statistically significant relationships between injury severity and safety belt use, mass ratio and ETS. We could not identify any statistically significant relationships between the EuroNCAP body region scores and real injury outcome except for the protection to pelvis-femur-knee in frontal impacts where scoring "green" is significantly better than scoring "yellow" or "red".

Scoring of anatomic injury after trauma: AIS 98 versus AIS 90--do the changes affect overall severity assessment?

BACKGROUND

Although several changes were implemented in the 1998 update of the abbreviated injury scale (AIS 98) versus the previous AIS 90, both are still used worldwide for coding of anatomic injury in trauma. This could possibly invalidate comparisons between systems using different AIS versions. Our aim was to evaluate whether the use of different coding dictionaries affected estimation of Injury Severity Score (ISS), New Injury Severity Score (NISS) and probability of survival (Ps) according to TRISS in a hospital-based trauma registry.

MATERIALS AND METHODS

In a prospective study including 1654 patients from Ulleval University Hospital, a Norwegian trauma referral centre, patients were coded according to both AIS 98 and AIS 90. Agreement between the classifications of ISS, NISS and Ps according to TRISS methodology was estimated using intraclass correlation coefficients (ICC) with 95% CI.

RESULTS

ISS changed for 378 of 1654 patients analysed (22.9%). One hundred and forty seven (8.9%) were coded differently due to different injury descriptions and 369 patients (22.3%) had a change in ISS value in one or more regions due to the different scoring algorithm for skin injuries introduced in AIS 98. This gave a minimal change in mean ISS (14.74 versus 14.54). An ICC value of 0.997 (95% CI 0.9968-0.9974) for ISS indicates excellent agreement between the scoring systems. There were no significant changes in NISS and Ps.

CONCLUSIONS

There was excellent agreement for the overall population between ISS, NISS and Ps values obtained using AIS 90 and AIS 98 for injury coding. Injury descriptions for hypothermia were re-introduced in the recently published AIS 2005. We support this change as coding differences due to hypothermia were encountered in 4.3% of patients in the present study.

The association between age, injury, and survival to hospital among a cohort of injured motorcyclists

Despite the significant increase in mortality among older motorcyclists during the past decade, few studies have addressed specific injuries or mortality rates among all those injured. The purpose of this study is to describe the crash and injury characteristics among a cohort of motorcyclists injured in Maryland, and to determine the influence of age and crash type on mortality, injury patterns, and place of death (scene vs. hospital). Possible biases introduced by studying only those hospitalized are described. Based on the findings, specific injury prevention strategies for older vs. younger riders are proposed.

Causes of death in US Special Operations Forces in the global war on terrorism: 2001-2004

INTRODUCTION

Effective combat trauma management strategies depend on an understanding of the epidemiology of death on the battlefield, resulting in evidence-based equipment, training, and research requirements.

METHODS

All Special Operations Forces (SOF) fatalities (combat and noncombat) in Operation Iraqi Freedom/Operation Enduring Freedom (OEF/OIF) from October 2001 until November 2004 were reviewed. All available autopsy and treatment records and photographs were used. In most cases, the immediate tactical situation was unknown. The review was performed by a multidisciplinary group including forensic pathologists, an SOF combat medic, and trauma surgeons. Fatalities were classified as having wounds that were either nonsurvivable or potentially survivable with existing training, equipment, and expertise on the battlefield. A structured review was performed evaluating the need for new equipment, training, or research requirements. Results were compared to autopsy data from Vietnam and modern civilian trauma center data. The study was approved by the Institutional Review Boards of the Armed Forces Institute of Pathology and the US Army Institute of Surgical Research.

RESULTS

During the study period, 82 SOF fatalities were identified. Autopsies were performed on 77 Soldiers. Five casualties died secondary to aircraft crash, their bodies were not recovered from the ocean. For the purposes of this study they were considered nonsurvivable. Eighty-five percent (n = 70) of the fatalities sustained wounds that were nonsurvivable, while the remaining 15% (n = 12) had wounds that were potentially survivable. Injury Severity Score (ISS) was higher in the nonsurvivable group (p < 0.05). Truncal hemorrhage accounted for 47% of deaths while extremity hemorrhage accounted for 33%. One casualty was noted at autopsy to have a tension pneumothorax as well as multiple sources of internal hemorrhage, one suffered an airway death, while another died of sepsis 56 days after injury. Of those casualties deemed to be nonsurvivable, there were 31 patients with 40 Abbreviated Injury Score (AIS) 6 injuries (p = .0011), and 53 patients with 104 AIS 5 injuries. Among the 12 deaths deemed to be potentially survivable, there were only 8 AIS 5 injuries. Deaths were largely caused by explosions (n = 35), gunshot wounds (n = 23), and aircraft accidents (n = 19). No new training or equipment needs were identified for 53% of the potentially survivable deaths while improved methods of truncal hemorrhage control need to be developed for the remainder. The review panel concluded that 85% of the deaths would not have been prevented at a civilian Level I facility. Available records, in most cases, did not contain information about the use of body armor, time to death after injury, or the ongoing tactical situation.

CONCLUSIONS

The majority of deaths on the modern battlefield are nonsurvivable. Current results are not different from previous conflicts. In Vietnam, reported potentially preventable death rates range from 5% to 35% and civilian data reports potentially preventable death rates ranging from 12% to 22%. Military munitions cause multiple lethal injuries. Current trauma training and equipment is sufficient to care for 53% of the potentially survivable deaths. Improved methods of intravenous or intracavitary noncompressible hemostasis combined with rapid surgery are required for the remaining 47% of the decedents.

Which of the Abbreviated Burn Severity Index Variables Are Having Impact on the Hospital Length of Stay?

Quality control is an important tool ensuring continuous medical efficacy. Outcome scores, however, are unfavorable from a statistical point of view, are not meaningful for less severely injured patients, and may put the treating physicians under pressure to limit therapeutic efforts. In this study the variables of the abbreviated burn severity index (ABSI), primarily an outcome score, were used to predict length of hospital stay (HLS), a continuous quantitative variable reflecting treatment costs and incidence of complications even in less severely injured patients. For 365 patients a multiple linear regression analysis was used to evaluate the influence of the ABSI variables on HLS. Among survivors, age and total body surface area burned (TBSA) contributed significantly to HLS, whereas for nonsurvivors only TBSA significantly influenced HLS. Neither gender nor presence of full-thickness burn or inhalation injury showed a significant influence on HLS. The impact of age and TBSA on HLS might be used as a benchmarking system to evaluate quality of care. However, although HLS is probably widely dependent on regional health care systems, TBSA and age proved to be the only variables of the ABSI to correlate with HLS.

A population-based comparison of CIREN and NASS cases using similarity scoring

The Crash Injury Research and Engineering Network (CIREN) provides significant details on injuries, and data on patient outcomes that is unavailable in the National Automotive Sampling System (NASS). However, CIREN cases are selected from specific Level I trauma centers with different inclusion criteria than those used for NASS, and the assertion that a given case is similar to the population of NASS cases is often made qualitatively. A robust, quantitative method is needed to compare CIREN to weighted NASS populations. This would greatly improve the usefulness and applicability of research conducted with data from the CIREN database. Our objective is to outline and demonstrate the utility of such a system to compare CIREN and NASS cases. This study applies the Mahalanobis distance metric methodology to determine similarity between CIREN and NASS/CDS cases. The Mahalanobis distance method is a multivariate technique for population comparison. Independent variables considered were total delta V, age, weight, height, maximum AIS, ISS, model year, gender, maximum intrusion, number of lower and upper extremity injuries, and number of head and chest injuries. The technique provides a unit-independent quantitative score which can be used to identify similarity of CIREN and NASS cases. Weighted NASS data and CIREN data were obtained for the years 2001-2005. NASS cases with Maximum AIS 3 resulted in a subset of 1,869 NASS cases, and 2,819 CIREN cases.

Major trauma and the injury severity score--where should we set the bar?

Major trauma is commonly defined using an Injury Severity Score (ISS) threshold of 15. Since this threshold was formulated, there have been significant developments in both the Abbreviated Injury Scale underlying the ISS, and trauma management techniques, both in the preventive and acute-care phases of trauma management. This study assesses whether this ISS threshold is appropriate when evaluating both mortality, and hospital-based indicators of morbidity, in a paediatric population using a large hospital trauma registry. Other registries and datasets using ISS >15 as an inclusion criterion may exclude a substantial body of data relating to significantly morbid trauma patients.

Pediatric material properties: a review of human child and animal surrogates

Because pediatric tissue is difficult for researchers to obtain, the biomechanical responses of adult humans have been studied much more extensively than those of children. Piglets, chimpanzees, and other animals have been used as child surrogates, but the tissue properties and responses to impact forces obtained from these animals may not directly correlate with the human child, and this correlation is not well understood. Consequently, only a handful of human pediatric tissue properties are known. Child anthropomorphic test devices employed in automotive safety have been developed largely by scaling data obtained from adult human cadaveric tests, where various scaling methods have been used to account for differences in geometry, material properties, or a combination of these two parameters. Similar scaling techniques have also been implemented to develop injury assessment reference values for child anthropomorphic test devices. Nevertheless, these scaling techniques have not yet proven to be accurate, in part because of the lack of pediatric data. In this review, the properties of pediatric human and animal surrogate tissue that have been mechanically tested are evaluated. It was found that most of the pediatric tissue that has previously been tested pertains to the head, neck, cervical spine, and extremities. It is evident that some body regions, such as the head and neck, have been tested to some extent since injuries to these regions are critical from an injury perspective. On the other hand, there is limited pediatric data available for the thorax, abdomen, thoracic and lumbar spines and fetal-related tissue. This review presents the pediatric data available in the literature and highlights the body regions where further testing is needed.

Onset and maintenance of psychiatric disorders after serious accidents

The purpose of this study was to prospectively investigate the onset, course, and remission of psychiatric disorders in the first 6 months after a serious accident for consecutive patients in a hospital emergency department. Participants were 58 patients aged 18-65 who were assessed shortly after attending a hospital emergency department and were followed up 6 months afterwards. Patients were interviewed with regard to past and current psychiatric history using different instruments (e.g. SCID for DSM-IV). Prior to their accidents, 35% of all subjects had experienced one or more psychiatric disorders (lifetime prevalence). Shortly after the accident, the incidence of Acute Stress Disorder (7%), subsyndromal Acute Stress Disorder (12%), and adjustment disorder (1.5%) was increased as a reaction to the accident. At this time, 29% of all patients suffered from an acute psychiatric disorder. Six-months after the accident, 10% of the subjects met criteria for Major Depression, 6% for PTSD, 4% for subsyndromal PTSD, and 1.5% for Specific Phobia as newly developed disorders. The course of the psychiatric disorders shows that those patients who met criteria for any psychiatric diagnosis shortly after the accident ran a much higher risk for developing new or comorbid psychiatric disorders in the future.

AIS 2005: a contemporary injury scale

To determine and to quantify outcome from injury demands that multiple factors be universally applied so that there is uniform understanding that the same outcome is understood for the same injury. It is thus important to define the variables used in any outcome assessment. Critical to defining outcomes is the need for a universal language that defines individual injuries. The abbreviated injury scale (AIS) is the only dictionary specifically designed as a system to define the severity of injuries throughout the body. In addition to a universal injury language, it provides measures of injury severity that can be used to stratify and classify injury severity in all body regions. Its revision, AIS 2005 will be discussed here.