Persistent hyperglycemia in severe traumatic brain injury: an independent predictor of outcome

In patients with severe traumatic brain injury (TBI), admission hyperglycemia is associated with poor outcome. The effect of persistent hyperglycemia (PH) on outcome in severe TBI, however, remains unknown. We performed a retrospective review of all blunt trauma patients with severe TBI (head Abbreviated Injury Score > or = 3) admitted to the intensive care unit at a Level I trauma center from January 1998 through December 2005. Admission and daily intensive care unit blood glucose levels up to the end of the first week were measured. PH was defined as an average daily blood glucose > or = 150 mg/dL on all days for the first week of the hospital stay. TBI patients with and without PH were compared with respect to baseline demographics, injury characteristics, and outcomes. Independent risk factors for mortality were identified using logistic regression analysis. One hundred and five (12.6%) out of 834 severe TBI patients had PH. Patients with PH were older, more severely injured, and had worse head injury compared with patients without PH. After adjusting for significant risk factors, PH was identified as an independent risk factor for mortality (odds ratio (OR): 4.91 [95% confidence interval (CI), 2.88-8.56, P < 0.0001]). PH is associated with significantly higher mortality rates in severe TBI patients.

[Assessment of the injury severity score in evaluation of multiple maxillofacial injuries]

OBJECTIVE

To compare the superiority of abbreviated injury scale (AIS) 2005 and AIS 1998 for evaluation of maxillofacial injury severity and major trauma outcome.

METHODS

A total of 450 trauma patients evaluated by AIS 2005 and AIS 1998 from July 2005 to January 2007 were analyzed retrospectively.

RESULTS

The mortality and morbidity of complications in trauma patients were ascending with the increase of injuries severity score (ISS). The ascending tendency in mortality was more notable in injuries severity score (ISS) > 20 in AIS 2005. The mortality in trauma patients in AIS 2005 was significantly lower than those in AIS 1998 in ISS > 15, < 20 (P = 0.001). The ascending tendency to morbidity of complications was more notable in other ISS groups in AIS 2005 than those in AIS 1998.

CONCLUSIONS

The evaluation of injury severity and major trauma outcome by ISS based on AIS 2005 is superior to based on AIS 1998. It is reasonable to definite severe trauma by ISS value greater than 20 in AIS 2005.

Trauma care audit using Srinagarind hospital's audit filter

BACKGROUND

To audit trauma care (including the mortality rate and obstacles faced by the authors) at Srinagarind (University) Hospital using the trauma audit filter.

MATERIAL AND METHOD

Conduct a prospective, descriptive, study of trauma patients who received trauma medical care at Srinagarind Hospital, Khon Kaen University, Thailand, between January and May 2006. Srinagarind Hospitals trauma audit filter was used to audit trauma care. The audit filter comprised 14 criteria (i.e., 1) emergency medical service; 2) accident and emergency out-patient service; 3) in-patient service). Any filter that generated a "Yes" response was investigated to find the reason(s). The obstacles and mortality were also recorded.

RESULTS

The authors enrolled 3209 patients. The mortality rate was 0.5% (95% CI 0.3-0.8). Emergency medical service, accident and emergency out- and in-patient service were rated satisfactorily. The reported obstacles were lack of hospital beds, inappropriate locale for trauma care, financial process, admission process, and lack of equipment.

CONCLUSIONS

Srinagarind Hospital's audit filter had the capability to audit trauma care. Overall trauma care at Srinagarind Hospital was satisfactory albeit improvements are needed.

Aging is not a risk factor for femoral and tibial fractures in motor vehicle crashes

OBJECTIVE

To determine the effect of aging on the occurrence of femoral and tibial fractures during vehicular crashes.

METHODS

The Crash Injury Research and Engineering Network (CIREN), which includes occupants of a vehicle < 8 years old with at least one AIS > or = 3 or two AIS > or = 2 injuries in different body regions, comprised the study population. The occurrence of femoral and tibial fractures during vehicular crashes was analyzed in relation to age and other confounders [gender, BMI, stature, change in velocity (Deltav), restraint use, occupant position (driver vs. passenger) and principal direction of force (PDOF)] using chi2, Mantel-Haenszel chi2 and student t test. Multiple logistic regression (MLR) models were built for the prediction of femoral and tibial fractures with age as the independent variable and possible confounders as co-variates. An alpha = 0.05 was used for all statistics.

RESULTS

The incidence of femoral and tibial fractures in the study population (N=1,418) was 23% and 27%, respectively. Univariate analyses revealed a negative association between increasing age and femoral fractures and no association between age and tibial fractures. MLR models revealed no clear effect of increasing age on the occurrence of either femoral or tibial fractures. Obesity, frontal PDOF, and high Deltav affected the occurrence of femoral fractures. Tibial fractures were influenced by occupant position (driver), frontal PDOF, high Deltav and shorter stature.

CONCLUSION

Despite the known changes in bone composition and strength with aging, elderly vehicular occupants do not experience higher odds of incurring femoral and tibial fractures during crashes.

Injury risk for children in rear impacts: role of the front seat occupant

As more children move to the rear rows, there is a need to understand the rear impact environment for children to guide future regulatory and due care activities in this impact direction. A probability sample of 1,035 restrained child occupants, aged 0-12 years, seated in a second row outboard position in rear impact tow-away crashes, weighted to represent 10,079 children, was collected from an on-going child specific crash surveillance system between 3/1/00 and 12/31/06. These data were analyzed to quantify the overall injury risk and the influence of both front seat occupant presence and reported front seat back deformation on injury risk. Overall risk of AIS 2+ injury for restrained child occupants seated in the rear row outboard position in rear impact crashes was 2.3%. Occupants were seated in front of these children in 71% of cases and deformation of the front seat back into the child's space was reported in 8% of cases. For those children with seatback deformation occurring directly in front of them, there was a doubling of the injury risk (4.8% vs. 2.1%, adjusted OR=2.4, 95% CI=1.2-4.8). This paper provides the first population-based estimates of the injury risk of rear row-seated children in rear impact crash events and points to the importance of understanding the role of front seat back design on rear impact injury risk for both the front seat and rear seat occupants.

Risk of permanent medical impairment (RPMI) in road traffic accidents

In addition to investigating risk of death due to road traffic injuries, there is a need to better describe the risk of serious consequences. This study assessed risk of permanent medical impairment based on road traffic injuries classified according to AIS-2005. Injured car occupants were followed for at least 5 years to assess permanent medical impairment. After an initial injury, the risk of permanent impairment was established for injuries to different body regions and AIS levels. Degree of impairment was assessed according to a manual used by all Swedish insurance companies. Those included in the study were 20,484 car occupants injured in crashes that occurred between 1995 and 2001. Three risk levels of sustaining a permanent medical impairment (RPMI) were made. It was concluded that almost 10% of all car occupants with AIS1 injuries sustained a permanent medical impairment. It is therefore important to include minor injuries leading to impairment when measuring loss of health due to road traffic crashes. Furthermore the highest risk of sustaining a permanent medical impairment from an AIS1 injury was associated with injuries to the cervical spine and upper and lower extremities. One third of AIS3 head and cervical spine injuries led to the highest RPMI level of impairment. Injuries to the thorax and abdomen gave the lowest risk of permanent medical impairment on all AIS levels and all impairment levels. The result can be used for road transport system strategies, and for making priority decisions in vehicle design.

Minor crashes and 'whiplash' in the United States

In the United States there is currently a paucity of available real world minor rear crash data with struck vehicle delta-V, or speed change, less than or equal to 15 kilometers per hour. These data are essential as researchers attempt to define 'whiplash' injury risk potential in these minor crashes. This study analyzed a new set of 105 U.S. minor rear aligned crashes between passenger vehicles. Mean struck vehicle delta-V and acceleration were 6.3 km/h (s.d. = 2.1 km/h) and 1.4 g (s.d. = 0.5 g), respectively. A total of 113 struck vehicle occupants were diagnosed within five weeks post-crash with 761 ICD-9-CM complaints and 427 AIS injuries (99.5% AIS1) attributed to the crashes. No striking vehicle occupants reported complaints. The main ICD-9-CM diagnoses were 40.6% cervical, 22.5% lumbar/sacral and 10.2% thoracic and the main AIS1 diagnoses were 29.7% cervical, 23.2% lumbar/sacral and 14.3% thoracic. The diagnosis disparity was mainly due to coding for pre-existing degenerative diagnosis in ICD-9-CM. Degenerative spine conditions were not significant for increased AIS1 injury risk. Surprisingly, many non-'whiplash' diagnoses were found. The AIS injury diagnosis distribution and frequency in these minor delta-V crashes did not correspond with previous minor rear crash studies. A prospectively collected and unbiased minor rear crash databank in the model of CIREN or NASS is highly desirable to verify or refute these results for the U.S. population since the current study cohort may have been influenced by litigation.

A field data analysis of risk factors affecting the injury risks in vehicle-to-pedestrian crashes

The head, torso, and lower extremity are the most commonly injured body regions during vehicle-to-pedestrian crashes. A total of 312 cases were selected from the National Automotive Sampling System (NASS) Pedestrian Crash Data Study (PCDS) database to investigate factors affecting the likelihood of sustaining MAIS 3+, AIS 3+ head, AIS 3+ torso, and AIS 2+ lower extremity injuries during vehicle-to-pedestrian frontal crashes. The inclusion criteria were pedestrians: (a) aged 14 years or older, (b) with a height of 1.5 m and taller, and (c) who were injured in an upright standing position via vehicle frontal collision. The injury odds ratios (ORs) calculated from logistic regression analyses were used to evaluate the association between selected injury predictors and the odds of sustaining pedestrian head, torso, and lower extremity injuries. These predictors included a crash factor (impact speed), pedestrian factors (age, gender, height, and weight), and vehicle factors (front bumper central height, front bumper lead, ground to front/top transition point height (FTTPH), and rear hood opening distance (RHOD)). Results showed that impact speed was a statistically significant predictor for head, torso, and lower extremity injury odds, as expected. Comparison of people 65 years of age and older to young adults aged 14 to 64 showed that age was also a significant predictor for torso (p<0.001, OR=23.8) and lower extremity (p=0.020, OR=2.44) injury odds, but not for head injuries (p=0.661). Vehicles with higher FTTPH and more vertical frontal structures were aggressive to pedestrians, especially regarding injuries to the torso. A very short RHOD would be more likely to lead the pedestrian to impact the windshield and windshield frame, thus increasing the head injury risk.

Fatality risk and the presence of rib fractures

Rib fractures may be dismissed as clinically insignificant, or of secondary importance in a patient presenting with other serious injuries, especially if the patient is young. This study assesses the effect of concomitant rib injuries on fatality risk following a car crash, and compares the effect as a function of patient age. The National Trauma Databank was sampled to identify 181,331 adults that were in motor vehicle crashes and had complete data available. Characteristics among several populations were compared, including the association between rib fractures and fatality risk in two age groups (18 to 45 years old and over 64 years old). Descriptive statistics were compiled to contrast the injury patterns and outcomes. Propensity scores were then generated using logistic regression, where the "treatment group" was those patients with rib fractures of at least an abbreviated injury scale (AIS) 3. Covariates for generating the propensity score included gender and the presence or absence of AIS 3, 4 or greater injuries to the head, abdomen or pelvis. Matching was performed using calipers on the propensity scores for all patients within the two age groups. Odds ratios for the outcome death were calculated for the matched datasets and compared between the two age groups. The probability that an adult with automotive blunt trauma had a rib injury as the maximum AIS (MAIS) increased significantly (p<0.001) with age. Furthermore, the probability of the patient having an MAIS defined by rib fractures increased significantly with age for adults who died with a thoracic MAIS: from 30.4% at age 21 to 51.3% at age 65. Rib fractures defined the MAIS for 55.9% of all patients over age 60 who died with a thoracic MAIS. In other words, over 55% of patients over 60 who died of a chest injury had no injury worse than rib injuries. The odds ratio for death for younger patients (aged 18-45) was 1.4 (95% CI 1.3-1.6) if rib fractures of at least AIS 3 or greater were present. For older patients (over 64 years) the odds ratio was 2.5 (95% CI 2.3-2.8). In other words, regardless of the presence or absence of concomitant trauma, crash-injured patients with rib fractures of at least AIS 3 have a significantly increased risk of in-hospital mortality, and of two patients having similar non-rib trauma, one with AIS 3+ rib fractures has a substantially higher expected risk of death than one without. This effect is more dramatic for older patients.

Injury mechanisms and severity in narrow offset frontal impacts

Current standard frontal crash tests include full frontal or 40% offset. Frontal impacts with offsets less than 40% and corner impacts have received little attention. Because of the limited engagement of vehicle structures that would permit less energy dissipation, these crashes have the potential for severe trauma to the near-side occupant. Narrow offset and corner-impact crashes under a frontal impact classification were analyzed using data obtained from the United States Department of Transportation National Highway Traffic Safety Administration crash databases: Crash Injury Research and Engineering Network (CIREN) and the National Automotive Sampling System (NASS) 2000-2006. A subset of crashes that could be defined clearly as narrow offset crashes were then examined. The Collision Damage Classification (CDC) classification was used to obtain only crashes with a "FLEE" code for drivers and a "FREE" code for right front passengers. These codes were used to separate out crashes that had bumper and lower vehicle engagement and less than 41 cm of front vehicle damage. The NASS data indicated that corner impacts ("Y" and "Z" type) and narrow overlap ("L" and "R" type) constitute 26 % each of all frontal impacts. When occupants were severely injured in frontal crashes 20 % of the occupants were in "L" and "R" type crashes and 31 % were in "Y" and "Z" type crashes. The percentage of near side "FLEE" and "FREE" crash occupants with severe injuries by body region demonstrated that head, thorax, upper, and lower extremity injuries dominate the data set. For the 71 CIREN cases, lower extremity injuries dominated. The injury severity score did not correlate well with assumed severity parameters like extent of crush and delta-V, however, crashes with extent zones 2-5 had a greater percentage of occupants with chest and spine injuries than crashes with extent zones 6-9. Vehicle rotation after front impact in extent zone 2-5 crashes may be influential in airbag effectiveness.

Age thresholds for increased mortality of three predominant crash induced head injuries

Trauma in the US's increasingly aged population will pose medical, engineering, and legislative challenges in the coming decade. This study sought to identify the age threshold of maximal risk for patients with the three most common isolated types of head injuries from motor vehicle crashes (MVCs). Receiver-operator characteristic analysis was used to identify the quantitative age threshold associated with increased mortality for the three most common MVC-induced types of head injuries. For each injury, an algorithm using multivariable logistic regression modeling was implemented to examine mortality as a function of age, adjusted for the GCS motor score and patient gender. The age threshold that maximized the area under the receiver operator characteristic curve (AUROC) was identified and the curve examined. The increased adjusted odds ratio (AOR) for death associated with each threshold was estimated along with 95% confidence intervals. Data used was from the American College of Surgeons National Trauma Data Bank (NTDB) version 7, Motor Vehicle Crash cases from Jan 1, 2001 to Dec 31, 2006. Three types of head injuries were of a sufficiently high incidence and severity level to be included in the study; the AIS 140684.3 (Cerebrum, Subarachnoid Hemorrhage, n=499), AIS 140650.4 (Cerebrum, Subdural Hematoma NFS, n=273), and AIS 140629.4 (Hematoma/Hemorrhage, Not Further Specified, n=123). The age thresholds are 58 (AOR=4.12, 95% CI 1.21-14.07, p=0.024), 54 (AOR=4.71, 95% CI 1.08-20.46, p=0.039) and 47 (AOR=15.44, 95% CI 2.94-81.2, p=0.001), respectively. Maximal AUROC values ranged from 0.89-0.93. This data along with data on injury mechanism has been used to provide information on the ideal 'threshold' beyond which age becomes an important factor for these three types of head injuries. This is the first study to quantitatively estimate the mortality threshold age for common isolated head injuries. This study has potential implications in the arena of safety design for the elderly, automated crash notification, and auto safety legislation.

Injury reduction opportunities of far side impact countermeasures

Over 17,000 non-struck or far side occupants in side and rollover crashes are seriously or fatally injured annually in the US. Although no legal or rating tests exist for far side crashes, test methods including appropriate dummies as well as countermeasures have been recently suggested. The aim of this study was to establish the incidence and risk of injury / fatality as a function of vehicle change in velocity (Deltav) for the most frequent injuries of belted, far side occupants in side impacts. The study was based upon the NASS/CDS 1995-2006 records of 5,653 occupants exposed to a far side crash. 401 of these were seriously or fatally injured. Combining this data with new and previously published crash test results, the potential opportunities of various concepts of far side countermeasures were evaluated. Head/thorax injuries caused by interaction with the struck side interior were found to dominate. Countermeasures such as side support airbags and altered three-point belt geometry (e.g. four-point belts) are relevant for Deltav of at least 20-30 km/h. The opportunity for mitigating AIS3+ injuries in these severity ranges was found to be 19%- 57%. Countermeasures such as struck-side curtains are able to provide cushioning at Deltav 30 to 50 km/h, which would cover almost a third of all fatalities.

[Injuries due to parachute jumping]

BACKGROUND

Parachuting is performed for sportive and occupational purposes and demands a high level of controlled physical performance. In conjunction with the growing interest in parachuting, injury rates in the emergency departments are also increasing. We thus aimed to evaluate the mechanism and characteristics of injuries due to parachuting.

METHODS

Parameters of the patients injured and presenting to the emergency department, including mean age, body area exposed to injury, definite diagnosis, applied treatment modalities, and admission to/discharge from the hospital, were all recorded in a previously prepared form and analyzed. Degree of injury was detected by calculating the Injury Severity Score (ISS) using the Abbreviated Injury Scale (AIS).

RESULTS

Mean ISS of the patients was 8.15+/-4.29. The most commonly affected body sites were the extremities. Of the extremity injuries, 13 (81%) involved lower extremities and 3 (19%) involved upper extremities. The most commonly affected site in the lower extremities was the ankle (47%). Head injuries followed extremity injuries as the second most affected site.

CONCLUSION

Injuries from parachute jumping mostly occur during landing due to loss of balance. Loss of balance was seen to result from change in wind direction and personal factors. When jumpers acquire adequate knowledge about phases of parachute jumping and landing, probability of injury will decrease.

Injury risks between first- and second-generation airbags in frontal motor vehicle collisions

BACKGROUND

Airbags in vehicles manufactured after 1997 were depowered to decrease injury risks for infants/children and small adults. It is possible that compared to earlier airbags second-generation airbags provide less injury protection due to their depowered nature.

METHODS

A cohort study was conducted using 1995-2004 national data. Risk ratios (RRs) and 95% confidence intervals (CIs) compared injury risks for occupants involved in frontal collisions in vehicles wherein a first- or second-generation airbag deployed by body region and injury severity using the Abbreviated Injury Scale (AIS). Associations were adjusted for crash severity, seatbelt use, seat position, occupant location, and vehicle curb weight.

RESULTS

For upper extremity injuries reduced RRs were observed for AIS 1 or greater (RR=0.76, CI 0.67-0.86), AIS 2 or greater (RR=0.76, CI 0.58-1.00) and AIS 3 (RR=0.81, CI 0.64-1.03). Elevated risks were observed for AIS 5 thoracic injuries (RR=1.46, CI 1.04-2.07) but were made null when differences in age and gender were adjusted for.

CONCLUSIONS

Vehicles equipped with first- and second-generation airbags appear to offer similar protection for front-seated occupants. The observed decreased risks for upper extremity injury and increased risks for severe thoracic injuries warrant further attention.

Disparities in work-related injuries associated with worker compensation coverage status

BACKGROUND

This exploratory study addresses patterns of injury in an emerging population of contingent workers who are not covered by either worker's compensation (WC) or health insurance. The primary purpose is to improve the information base regarding the entire population of uninsured, injured workers. Because Latino workers are over-represented in the uninsured group, we include additional characterization of their patterns of injury. Recent studies have found that worker compensation claims and reports address a shrinking proportion of occupational injury and exposure, and about two-thirds of occupational injuries are not captured in the U.S. national surveillance system.

METHODS

Following the NEISS methodology, a work-relatedness indicator was retrieved for emergency department (ED) visits to an academic health center in fiscal year 2005.

RESULTS

Twenty percent of self-declared work-related injuries were not associated with self-reported WC coverage. Parametric and non-parametric statistical analysis found several significant disparities in workers without WC. These disparities included a higher proportion of Latinos, workers under age 25, and construction workers. In the uninsured group, Latino workers had a higher proportion of moderate and severe injuries. Nearly all (92 percent) workers without WC also lacked health insurance. Injured low-income workers who lack access to both WC and employer-sponsored health insurance comprise an increasing percentage of the occupationally injured. Our exploratory study found this to be particularly true in high-risk populations.

CONCLUSIONS

Work-relatedness indicators collected routinely in ED and outpatient settings should be incorporated into standard reporting systems to facilitate more accurate and comprehensive surveillance and better-targeted interventions.

Maxillofacial trauma in major trauma patients

BACKGROUND

Trauma has been identified as a major public health problem in Australia. Maxillofacial trauma constitutes a significant proportion of trauma, although epidemiological studies in Australia are few. The purpose of this study was to assess the prevalence and the epidemiological pattern of maxillofacial trauma occurring in major trauma patients.

METHODS

Data were obtained from the Victorian State Trauma Registry, which included all major trauma patients in Victoria. All data relating to maxillofacial trauma defined according to Abbreviated Injury Scale and International Classification of Diseases codes from 1 July 2001 to 30 June 2004 were selected. Data collected included demographic and injury details, and operative procedures carried out.

RESULTS

Sixteen per cent of major trauma patients sustained maxillofacial trauma. The highest frequency of injuries occurred in the 15-24 years age group. More males were affected than females (3:1). The majority of injuries were due to transportrelated causes (69 per cent) and occurred mostly on roads, streets or highways (70 per cent). Falls were the cause of 15 per cent of injuries, 10.5 per cent of these injuries were fatal while 20.7 per cent needed rehabilitation. The most common type of bony injury was a fractured maxilla.

CONCLUSION

The need for preventive strategies to be reinforced has been highlighted as transport-related injuries remain high especially in the younger age groups.

Passenger car collision fatalities--with special emphasis on collisions with heavy vehicles

Between 1995 and 2004, 293 passenger car occupants died in collisions with other vehicles in northern Sweden (annual incidence: 3.3 per 100,000 inhabitants, 6.9 per 100,000 cars, or 4.8 per 10(9)km driven); half of these deaths involved heavy vehicles. The annual number of passenger car occupant deaths per 100,000 cars in car-truck/bus collisions has remained unchanged since the 1980s, but in car-car collisions it has decreased to one third of its former level. As crash objects, trucks and buses killed five times as many car occupants per truck/bus kilometer driven as did cars. The collisions were characterized by crashes in the oncoming vehicle's lane, under icy, snowy, or wet conditions; crashes into heavy vehicles generally occurred in daylight, on workdays, in winter, and on 90 and 70 km/h two-lane roads. Head and chest injuries accounted for most of the fatal injuries. Multiple fatal injuries and critical and deadly head injuries characterized the deaths in collisions with heavy vehicles. An indication of suicide was present in 4% of the deaths; for those who crashed into trucks, this percentage was doubled. Among the driver victims, 4% had blood alcohol levels above the legal limit of 0.2g/L. Frontal collision risks might be reduced by a mid-barrier, by building less injurious fronts on trucks and buses, by efficient skid prevention, and by use of flexible speed limits varying with road and light conditions.

Rollover injury: effects of near- and far-seating position, belt use, and number of quarter rolls

PURPOSE

Vehicle and occupant responses in rollovers are complex since many factors influence both. This study analyzes the following factors: 1) belt use, 2) seated position with respect to the lead side in the rollover, 3) another front occupant in the crash, and 4) number of quarter rolls. The aim was to improve our understanding of rollover injury mechanisms.

METHOD

Rollover accidents were analyzed using 1992-2004 NASS-CDS data. The sample included adult drivers and right-front passengers. All occupants were evaluated and then a subset of non-ejected occupants was analyzed. Using roll direction and seating position, the sample was divided into near- and far-seated occupants. Injury and fatality risks were determined by seatbelt use, occupancy, rollover direction, and number of quarter rolls. Risk was defined as the number of injured (e.g., MAIS 3+) divided by the number of exposed occupants (MAIS 0-6). Significance in differences was determined. A matched-pair analysis was used to determine the risk of serious injury for near- and far-seated occupants who were either belted or unbelted in the same crash.

RESULTS

For all occupants, serious injury risks were highest for far-seated, unbelted occupants at 18.1% +/- 4.8%, followed by near-seated unbelted occupants at 12.0% +/- 3.5%. However, the difference was not statistically significant. Belted near- and far-seated occupants had a similar injury risk of 4.3% +/- 1.2% and 4.0% +/- 1.2%, respectively. For non-ejected occupants, serious injury risk was 9.5% +/- 3.2% for far-seated unbelted occupants and 4.9% +/- 2.1% for near-seated unbelted occupants, not a statistically significant difference. Serious injury risk was similar for belted near- and far-seated non-ejected occupants, at 3.6% +/- 1.1%. Seatbelts were 64.2%-77.9% effective in preventing serious injury for all occupants and 62.1%-26.5% for far- and near-seated, non-ejected occupants, respectively. Based on the matched pairs, seatbelts were less effective for near-seated (5.0%) compared to far-seated (2.8%) occupant MAIS 3+F risks. This was similar for non-ejected occupants. An unbelted near-seated occupant increased the risk for a belted far-seated occupant by 2.2 times, whereas an unbelted far-seated occupant increased the risk for a belted near-seated occupant by 10.2 times. For all occupants, the risk of serious injury increased with the number of quarter rolls, irrespective of seated position. For near-seated occupants, seatbelt effectiveness was higher in < or =1 roll than 1+ roll, at 72.3% compared to 28.3%. For far-seated occupants, seatbelt effectiveness was similar in < or =1 and 1+ roll samples at 78.3% and 76.8%, respectively. Near-seated occupants had the lowest serious injury risk when they were the sole occupant in the vehicle. This was also true for non-ejected occupants. However, far-seated occupants had a lower injury risk when another occupant was involved in the crash.

CONCLUSIONS

The effect of carrying another occupant appears to reduce the risk of serious injury to far-seated occupants. However, near-seated occupants are better off being the sole occupant in the vehicle. Seatbelt effectiveness was lowest at 28.3% for non-ejected, near-seated occupants in 1+ rolls. This finding deserves further evaluation in an effort to improve seatbelt effectiveness in rollovers. For belted drivers alone in a rollover, fatality risks are 2.24 times higher for the far- versus near-seated position. Analysis of rollovers by quarter turns indicates that occupants are both far-side and near-side in rollovers. The extent to which this confounds the relationship between roll direction, seating position, and injury risk is unknown.

Intra-osseous access (EZ-IO) for resuscitation: UK military combat experience

Military trauma produces predominantly blast and fragmentation injury, commonly resulting in haemorrhagic shock. Injury patterns to limbs are such that the conventional sites for venous cannulation may be unsuitable. The EZ-IO (Vidacare, San Antonio) system is one of a number of novel products designed for intraosseous (IO) access in adults or children. In three months of combat casualty care in Helmand Province, Afghanistan, the UK Defence Medical Services used EZ-IO for emergency vascular access on 26 patients (16 adults; 10 children). 23/26 patients had IO access obtained in the emergency department; 3/26 had pre-hospital IO access within a tactically flying helicopter. A total of 32 needles were inserted, with 97% effective function. IO needles were used to administer fluid (crystalloid, packed red cells and fresh frozen plasma) and drugs (analgesics, cardiac arrest drugs, antibiotics, drugs for both rapid sequence induction and maintenance of anaesthesia). No complication of infection was noted, but pain was observed in responsive patients with the pain of infusion exceeding that of the underlying injuries in 3 cases.

Comparison of mid-block and intersection-related left turn collisions

OBJECTIVES

To evaluate the factors that might influence an occupant's injury severity during a left turn movement.

METHODS

We used the National Automotive Sampling System Crashworthiness Data System (1995-2005) to compare crash characteristics and injury outcome between intersection and midblock left turn collisions.

RESULTS

A total of 7,396 collisions were evaluated. Traffic control devices were present in 82% of intersection and 10% of mid-block collisions. After adjustment for potential confounding variables, drivers' injury severity was not significantly associated with the crash location. However, front seat passengers in mid-block collisions had 72% higher odds of experiencing an injury with injury severity score > or =9 (odds ratio: 1.72, 95% confidence interval: 1.09-2.69). Our analysis did not show that drivers or passengers in larger vehicles, e.g., sport utility vehicles and mini-vans, were at lower risk of more severe injuries in comparison to the car occupants in sedans.

CONCLUSION

We found that in comparison to intersection-related left turn collisions, mid-block crashes are associated with more severe injuries for front seat passengers. Furthermore, size of the turning vehicle was not significantly associated with injury severity for drivers or front seat passengers.

[Motor vehicle accidents with entrapment. A medical and technical investigation of crash mechanism, injury pattern and severity of entrapment of motor vehicle occupants between 1983 and 2003]

AIM

Crash mechanisms, injury patterns, and severity of injury of entrapped motor vehicle occupants were analysed by the Accident Research Unit's scientific teams between 1983 and 2003.

RESULTS

Of the 1281 vehicle passenger entrapments in our study, 18.3% happened on highways, 25.6% on federal roads, 35.9% on country roads, and 18.3% on city roads. Of those involved, 69.9% were drivers, 19.4% were front passengers, and 8.5% were rear passengers. Coinvolved objects in car collisions were: other cars 30.9%, trucks 50.2%, objects 18.6%, and motorbikes 0.3%. Coinvolved objects in truck collisions were: other trucks 61.8% and objects 38.2%. The mean Delta-V was 42 km/h (cars 46.2, trucks 32.2). Maximum AIS levels were 31% I, 25.2% II, 19.4% III, 7.8% IV, 7.8% V, and 8.6% VI. Of injuries, 68.7% were to the head, 23.5% to the neck, 50.8% to the chest, 43.6% to upper extremities, 15.4% to the abdomen, 16.4% to the pelvis, and 52.9% to lower extremities. The incidence of multiple injuries (ISS>16) was 23.7%, and mortality was 15.9%.

CONCLUSION

Car drivers are more at risk of accidents with entrapment on rural streets, and truck drivers are more at risk on highways. In most cases car occupants crash with trucks or other cars, and truck drivers collide more frequently with other trucks or objects. Besides a high degree of severe single injuries, there is also a high incidence of multiple injury victims and high mortality. Of the fatalities, 74.5% occur during the preclinical course and 24.5% during the clinical course.

Initial presentation of older injured patients to high-volume hospitals is not associated with lower 30-day mortality in Medicare data

OBJECTIVE

To evaluate whether survival of older patients with severe injuries is positively associated with initial presentation to high-volume trauma hospitals.

DESIGN

Historical cohort study.

SETTING

We analyzed Medicare fee-for-service records. Cases were classified by maximum Abbreviated Injury Score (AISmax); those with isolated hip fractures or AISmax <3 were excluded. The initial hospital (emergency department or inpatient) for each case was classified by its number of included inpatient cases.

PATIENTS

Patients aged >or=65 with principal injury diagnoses (ICD-9 800-959, excluding 905, 930-939, 958) admitted to hospitals or who died in emergency departments during 1999.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirty-day mortality was determined using Medicare denominator data and modeled as a function of hospital volume, AISmax, age, gender, and comorbidity. We found that 95,867 patients (74,894 AISmax = 3; 17,932 AISmax = 4; 3,041 AISmax = 5) were managed in 4,391 hospitals. More than 90% of the interhospital transfers were from emergency departments, mostly from low-volume to high-volume hospitals, and were more frequent with greater severity. Regression models showed no difference in 30-day survival between patients taken first to low-volume hospitals (and possibly transferred) vs. patients taken directly to high-volume hospitals. Prior studies showing a positive or negative effect of hospital volume on survival of older patients could be replicated but their findings could not be generalized.

CONCLUSIONS

Existing systems of trauma care result in similar survival for older patients with serious injuries seen first at low-volume or high-volume hospitals.

Splenic Trauma in Scotland: Demographics and Outcomes

BACKGROUND

Splenic trauma is a common organ injury following blunt abdominal trauma. In order to establish the contemporary epidemiology of blunt splenic trauma in Scotland and to detect risk factors associated with patient outcomes, analysis of a multi-center database of trauma patients was performed.

METHODS

The study used data from a prospectively collated multicenter trauma database containing the details of 52,215 trauma patients admitted to participating Scottish hospitals over an 11-year period.

RESULTS

672 (1.3%) patients (530 males, 142 females) with splenic trauma were identified; of them, 579 (86.2%) had blunt trauma and 93 (13.8%) had penetrating trauma. The mean age of patients with blunt splenic trauma was 35.7 years (33.8 years for males, 42.0 years for females). Increasing age and female sex was significantly associated with mortality. The most common mechanism for injury was road traffic accidents (71%). In the series, 93.8% of patients had concomitant injuries including head injuries (46.5%), thoracic injuries (37.7%) and liver injuries (30%). A total of 299 (51.6%) patients proceeded to laparotomy, and 256 (44.2%) patients required ICU support. The overall mortality was 33.5%, and the median Injury Severity Score was 48 in patients who died, compared to 22 in those who survived. Increased mortality was associated with concomitant aortic, cardiac, or abdominal injuries. A number of independent risk factors were associated with increased risk of mortality, including concomitant injuries, increased age, and increased Injury Severity Score.

CONCLUSIONS

The incidence of splenic trauma is low, but it accounts for significant mortality. Outcome in the present study was worse in those with advanced age and associated injuries.

The role of early follow-up computed tomography imaging in the management of traumatic brain injury patients with intracranial hemorrhage

BACKGROUND

The purpose of this study was to investigate whether routine follow-up computed tomography (CT) for patients with head injury, in the absence of clinical indications, alters patient management.

METHODS

Nonpenetrating head injury patients admitted to San Francisco General Hospital during an 18-month period were reviewed. Patients not surgically treated at presentation and with a routine follow-up head CT within 24 hours were included. Surgical and nonsurgical interventions after repeat CT were assessed. Clinical and imaging parameters were correlated with progressive hemorrhagic injury (PHI) and with delayed development of surgical lesions.

RESULTS

PHI was identified in 49 (42%) of 116 patients. None of these patients required a nonoperative intervention in response to the PHI. Six of these patients developed a neurologic change concurrent with routine follow-up imaging and required operative intervention. Thus, no patient underwent an intervention in response to a worsening head CT in the absence of clinical findings. Of the six patients who developed a surgical lesion, two had increased intracranial pressure, one had a change in pupillary examination, three had worsening mental status, and one had change in the motor examination. Univariate risk factors for development of a delayed surgical lesion included 5 to 10 mm of midline shift (p = 0.001), basal cistern effacement (p = 0.01), and higher Marshall score (p = 0.01) on initial CT imaging.

CONCLUSIONS

Although PHI is common with head injury, delayed interventions in the absence of clinical indicators are uncommon. Our data suggest that early follow-up CT imaging in the setting of head trauma is not routinely indicated. We suggest that assessment, based on the severity of findings on initial brain imaging and serial clinical examinations, should guide the need for follow-up imaging in the setting of head trauma.