Splenic injury in side impact motor vehicle collisions: effect of occupant restraints.

BACKGROUND: Side impact motor vehicle collisions (MVCs) are associated with higher morbidity and mortality compared with other types of MVCs. The stiffness of the lateral aspect of the vehicle and restraint use may play a role. The purpose of this study was to evaluate the role of restraint use, vehicle size, and compartment intrusion on the incidence of splenic injury in side impact MVCs. METHODS: The National Automotive Sampling System was used to identify drivers involved in side impact collisions for the years 1996 to 1998. The incidence of splenic injury in these collisions was compared according to restraint use, vehicle size, and magnitude of vehicle crush. Information on the perceived cause of splenic injuries sustained in the MVC was also obtained from National Automotive Sampling System investigator records. RESULTS: Overall, among drivers involved in side impact MVCs, restraint use was associated with a significantly reduced rate of mortality (odds ratio [OR], 0.40; p < 0.0001) and splenic injury (OR, 0.76; p < 0.0001). Restrained drivers of small vehicles (<2,500 lb), however, had a higher incidence of splenic injury in both minimal (lateral intrusion < 30 cm) (OR, 60.1; p < 0.0001) and severe (lateral intrusion > 30 cm) (OR, 4.0; p < 0.0001) magnitudes of vehicle crush on the driver's side of the vehicle. For both midsize (2,500-3,000 lb) and large (>3,000 lb) vehicles, restraint use was associated with a lower risk of splenic injury regardless of the magnitude of crush. In nearly all cases of splenic injury, the left vehicle interior was the source of injury. CONCLUSION: Overall, restraint use is associated with lower rates of splenic injury and mortality in side impacts. Despite this fact, restrained drivers of small vehicles have a higher risk of splenic injury after lateral impact MVCs when compared with unrestrained drivers. Evaluation of the combined role of restraint use, crash, and injury patterns may provide novel insight regarding vehicle safety design features.

Acidic fibroblast growth factor attenuates the cytotoxic effects of peroxynitrite in primary human osteoblast precursors.

BACKGROUND: Skeletal injury and associated ischemia and inflammation induce the generation of pro-oxidants such as peroxynitrite (ONOO-), which has been demonstrated to induce apoptosis in several cell lines. Fibroblast growth factor (FGF-1) is important for coordinating osteogenesis and angiogenesis of osseous repair. In vitro studies were performed examining the effect of FGF-1 on human osteoblast progenitor stromal stem (HSS) cell proliferation, differentiation, and response to ONOO-. METHODS: HSS cells were isolated and growth kinetics determined in the presence and absence of FGF-1. The effect of FGF-1 on HSS cell expression of osteoblast-specific osteopontin and osteocalcin mRNA and protein was examined by reverse transcriptase polymerase chain reaction and Western blot techniques. To determine the sensitivity of HSS cells to ONOO- in the absence and presence of FGF-1 pretreatment, cells were exposed to varying concentrations of the oxidant and examined for cell death using quantitative fluorescence staining with fluorescein diacetate and propidium diacetate. RESULTS: Treatment of HSS cells with FGF-1 significantly enhanced cellular growth rates by 5 days (4.6 x 105 cells/mL vs. 3.1 x 105 cells/mL) and induced expression of both osteopontin and osteocalcin mRNA and protein. Exposure of HSS cells to ONOO- resulted in a dose- and time-dependent delayed cell death that was more characteristic of apoptosis than necrosis. Pretreatment of HSS cells with FGF-1 prevented ONOO- mediated apoptosis. CONCLUSION: In vitro, treatment of HSS cells with FGF-1 stimulates cell growth and induces expression of differentiation markers specific to osteoblasts. FGF-1 treatment renders osteoblast precursors resistant to the cytotoxic effects of ONOO-. These results suggest that FGF-1 promotes the progression of bone repair mechanisms by increasing the population of osteoblasts and imparting protection to the cell line from the hostile inflammatory environment.

Recurrent trauma in elderly patients.

HYPOTHESIS: Older patients (those aged > or = 70 years) who have experienced trauma have an increased risk of recurrent trauma. Demographic, medical, and functional factors are potential contributors to the risk of subsequent trauma among injured elderly patients. DESIGN: Retrospective follow-up study. PARTICIPANTS: Study participants were derived from the Longitudinal Study of Aging, an extension of the 1984 National Health Interview Survey focusing on persons who were aged 70 years and older in 1984. A cohort of elderly patients participating in the Longitudinal Study of Aging and hospitalized for injury in 1985 (n = 100) was identified using Medicare hospital discharge data. An uninjured cohort (n = 401) was also identified from the Longitudinal Study of Aging and matched for age (1 year) and sex. MAIN OUTCOME MEASURES: Risk of admission for trauma among the injured cohort compared with the uninjured cohort and associations between demographic, medical, and functional characteristics and trauma recurrence. RESULTS: Following adjustment for potential confounding factors, the injured cohort was 3.25 times more likely (95% confidence interval, 1.99-5.31) to be hospitalized for injury during the follow-up period compared with the uninjured cohort. Among the injured cohort, those at greatest risk of subsequent trauma included women and those with chronic medical conditions or functional impairments, the latter being the only factor independently associated with recurrence. CONCLUSIONS: Elderly patients who have experienced trauma are at increased risk of subsequent injury. Interventions to reduce the likelihood of trauma recurrence should focus on those with chronic illnesses and functional impairments.

The association between body habitus, restraint use, and fatality in motor vehicle collisions.

UNLABELLED: The purpose of this study was to determine if there is an association between body habitus, restraint use, and risk of death in motor vehicle collisions (MVC). METHODS: The 1995-1999 National Automotive Sampling System Crashworthiness Data System was utilized. RESULTS: Body habitus, when described by height and weight, is associated with fatality rates in restrained drivers. Body mass index as a descriptor of body habitus was not associated with fatality rates. CONCLUSIONS: The 50th percentile male Hybrid III Crash Dummy plays a major role in vehicular cabin interior design and crash testing. For drivers with a dissimilar body habitus, the vehicle cabin/body fit changes and the safety features perform differently which may account for these observations.