An analysis of 174,160 patients in 165 trauma centres in the United States was undertaken to determine the mortality of head injuries (HI) in vehicular crashes. In this series, 59,713 patients incurred an injury to the brain or skull of which 39,738 (66.6%) were due to vehicular crashes. Of these vehicular causes, 73.2% were vehicle occupants (VO), 15.3% were pedestrians (PED) and 11.5% were motorcyclists (MC). The overall mortality for patients with vehicular HI was 13.3%, but was lower in VO (11.5%) than in MC (15.3%) or PED (20.7%). In all cases, mortality of HI was higher than if no head injury (NHI) occurred; overall mortality for vehicular NHI=5.2%, VO=4.9%, MC=4.2%, PED =7.3%. Injury severity measured by Abbreviated Injury Scale (AIS)-85 had, as expected, a profound influence on mortality of both HI and NHI groups. For HI patients with no to moderate additional extracranial injury (AIS (sub extracranial injury) = 0-2), a linear relationship was found for HI with severity AIS (sub HI) = 2-5, approximated by MORTALITY (sub ECI = 0-2) = 13.6 x AIS (sub HI = 2-5) - 28.7. For more severe ECI of AIS = 3-5, for AIS (sub HI) = 2-5 mortality was approximated as expressed by MORTALITY (sub ECI = 3-5) = 13 x AIS (sub HI = 2-5) - 19.2. By combining mortality with frequency, mortality indices are derived that can serve as targets for prevention strategies. These data support the proposition that head injuries are the most important single cause of vehicular fatality in patients who survive sufficiently long to reach medical care.
Abstract