A field evaluation of real-life motor vehicle accidents: presence of unrestrained objects and their association with distribution and severity of patient injuries

A prospective study of children aged <16 years in motor vehicle collisions in Norway: severe injuries are observed predominantly in older children and are associated with restraint misuse

OBJECTIVE

The implementation of the compulsory wearing of seat belts (SBs) for children and improvements in child restraint systems have reduced the number of deaths and severe injuries among children involved in motor vehicle (MV) collisions (MVCs). Establishing the characteristics predictive of such injuries may provide the basis for targeted safety campaigns and lead to a further reduction in mortality and morbidity among children involved in MVCs. This study performed a multidisciplinary investigation among child occupants involved in MVCs to elucidate injury mechanisms, evaluate the safety measures used and determine the characteristics that are predictive of injury.

METHODS

A prospective study was conducted of all child occupants aged <16 years involved in severe MVCs in south-eastern Norway during 2009-2013. The exterior and interior of the MVs were investigated and the injured children were medically examined. Supplementary information was obtained from witnesses, the crash victims, police reports, medical records and reconstructions. Each case was reviewed by a multidisciplinary team to assess the mechanism of injury.

RESULTS

In total, 158 child occupants involved in 100 MVCs were investigated, of which 27 (17%) exhibited Abbreviated Injury Scale (AIS) scores of 2+ injuries and 15 (9%) exhibited AIS 3+ injuries. None of the children died. Of those with AIS 2+ injuries (n=27), 89% (n=24) were involved in frontal impact collisions and 11% (3/27) were involved in side impacts. Multivariate analysis revealed that restraint misuse, age, the prevailing lighting conditions and ΔV were all independently correlated with AIS 2+ injuries. Safety errors were found in 74% (20/27) of those with AIS 2+ injuries and 93% (14/15) of those with AIS 3+ injuries. The most common safety error was misuse of restraints, and in particular loose and/or improperly positioned SBs.

CONCLUSION

The risk of injury among child occupants is significantly higher when the child occupants are exposed to safety errors within the interior of the vehicle. Future campaigns should focus on the prevention of restraint misuse and unsecured objects in the passenger compartment or boot.

Physiologic, demographic and mechanistic factors predicting New Injury Severity Score (NISS) in motor vehicle accident victims

BACKGROUND

Current literature on motor vehicle accidents (MVAs) has few reports regarding field factors that predict the degree of injury. Also, studies of mechanistic factors rarely consider concurrent predictive effects of on-scene patient physiology. The New Injury Severity Score (NISS) has previously been found to correlate with mortality, need for ICU admission, length of hospital stay, and functional recovery after trauma. To potentially increase future precision of trauma triage, we assessed how the NISS is associated with physiologic, demographic and mechanistic variables from the accident site.

METHODS

Using mixed-model linear regression analyses, we explored the association between NISS and pre-hospital Glasgow Coma Scale (GCS) score, Revised Trauma Score (RTS) categories of respiratory rate (RR) and systolic blood pressure (SBP), gender, age, subject position in the vehicle, seatbelt use, airbag deployment, and the estimated squared change in vehicle velocity on impact ((Δv)(2)). Missing values were handled with multiple imputation.

RESULTS

We included 190 accidents with 353 dead or injured subjects (mean NISS 17, median NISS 8, IQR 1-27). For the 307 subjects in front-impact MVAs, the mean increase in NISS was -2.58 per GCS point, -2.52 per RR category level, -2.77 per SBP category level, -1.08 for male gender, 0.18 per year of age, 4.98 for driver vs. rear passengers, 4.83 for no seatbelt use, 13.52 for indeterminable seatbelt use, 5.07 for no airbag deployment, and 0.0003 per (km/h)(2) velocity change (all p<0.002).

CONCLUSION

This study in victims of MVAs demonstrated that injury severity (NISS) was concurrently and independently predicted by poor pre-hospital physiologic status, increasing age and female gender, and several mechanistic measures of localised and generalised trauma energy. Our findings underscore the need for precise information from the site of trauma, to reduce undertriage, target diagnostic efforts, and anticipate need for high-level care and rehabilitative resources.

Observational study of child restraining practice on Norwegian high-speed roads: restraint misuse poses a major threat to child passenger safety

OBJECTIVE

Restraint misuse and other occupant safety errors are the major cause of fatal and, severe injuries among child passengers in motor vehicle collisions. The main objectives of the present, study were to provide estimates of restraining practice among children younger than 16 years, traveling on Norwegian high-speed roads, and to uncover the high-risk groups associated with, restraint misuse and other safety errors.

METHODS

A cross-sectional observational study was performed in conjunction with regular traffic, control posts on high-speed roads. The seating and restraining of child occupants younger than 16, years were observed, the interior environment of the vehicles was examined, and a structured, interview of the driver was conducted according to a specific protocol.

RESULTS

In total, 1260 child occupants aged 0-15 years were included in the study. Misuse of restraints, was observed in 38% of cases, with this being severe or critical in 24%. The presence of restraint, misuse varied significantly with age (p<0.001), with the frequency being highest among child, occupants in the age group 4-7 years. The most common error in this group was improperly routed, seat belts. The highest frequency of severe and critical errors was observed among child occupants in, the age group 0-3 years. The most common errors were loose or improperly routed harness straps and, incorrect installations of the child restraint system. Moreover, 24% of the children were seated in, vehicles with heavy, unsecured objects in the passenger compartment and/or the trunk that were, likely to move into the compartment upon impact and cause injury. No totally unrestrained children, were observed.

CONCLUSIONS

This study provides a detailed description of the characteristics of restraint misuse and, the occupant's exposure to unsecured objects. Future education and awareness campaigns should, focus on children aged <8 years. The main challenges are to ensure correct routing and tightness of, harness straps and seat belts, correct installation of child restraints, and avoidance of premature, graduation from child restraints to seat belts only. Information campaigns should also advocate the use, of chest clips and address the potential risks of hard, heavy objects in the passenger compartment and, the importance of the placement and strapping of heavy objects in the trunk.