The impact of safety belt use on liver injuries in motor vehicle crashes: The importance of motor vehicle safety systems

One of the most common and serious motor vehicle crash (MVC) consequences is liver injury (LI). Based on clinical suspicion, early LI detection in the unstable patient will improve care and outcome of acute trauma. Identifying occupant and crash scene risk factors for LI from MVCs were the analysis' specific objectives. Intrusion, vehicle crush, principal direction of force, delta V (change in velocity), air bag deployment, safety belt use, sex, and age were identified, through network data, as LI risk factors. Four control groups without LI were compared to occupants with LI for: abdominal (ABD) Abbreviated Injury Scale score of 3 or more (ABD_3+); ABD Abbreviated Injury Scale score of 1 to 2 (ABD_1-2); any ABD (ANY_ABD); and no ABD injury (NO_ABD). LI risk odds ratio was computed after each control group was compared with LI occupants. Crash Injury Research and Engineering Network subjects with LI who were 5 years of age or more numbered 311. There was a 37.6 total mean Injury Severity Score. Safety belt restraint use without air bag deployment showed a strong and significant association with LI in comparison with each control group: liver injury - restrained + air bag not deployed versus ABD_3+, N = 217; OR = 2.4 (p < 0.001); ABD_1 to 2, N = 155; OR = 3.1; ANY_ABD, N = 317; OR = 2.6; NO_ABD, N = 1,519; OR = 4.4. This association was independent of principal force direction and passenger or driver status. There was also a strong and significant association between LIs and greater vehicle interior intrusion. During MVCs, there was a strong association between safety belt restraint use with LIs in the absence of air bag deployment. The trauma surgeon may find this data to have profound importance during resuscitation as an early LI indicator. There may also be important implications in these findings for future research efforts for motor vehicle safety system improvement and mortality and morbidity reduction related to United States MVCs.