Abstract
Background
Motor vehicle collisions (MVCs) are a leading cause of injury in the US. While the probability of collision with a pedestrian (PMVC) has declined in recent years, the probability of a pedestrian fatality has risen. Our objective was to determine whether older age impacts potential outcomes in patients involved in low-velocity PMVCs.
Materials and methods
We performed a retrospective-cohort study of adult patients aged >14 years involved in low-velocity pedestrian–MVCs (<15 miles per hour [24.14 km/h]), presenting to an urban level I trauma center from January to November 2013. Subjects were identified via trauma registry and stratified: ages 15–49 years and ≥50 years. Electronic medical records were reviewed for demographics, vital signs, and laboratory results on initial presentation, presence or absence of systemic inflammatory response syndrome (SIRS), shock index (SI), injury-severity score (ISS), length of stay (LOS), and survival to discharge. For statistical analysis, χ2 or Student’s t-tests were utilized.
Results
Our study included 145 patients (77 female) with a mean age of 41.9±3 years; 95 patients were aged 15–49 years (mean 31.9±2.2 years), and 50 patients were aged ≥50 years or older (mean 62.44±2.9 years). Mean ISS was 10.05±1.95, mean SI was 0.68±0.03, and mean LOS was 3.67±0.57 days. A total of 41 patients met SIRS criteria on arrival, and nine patients expired (6.2%). Mean ISS (15.64±4.42 vs 7.1±1.64, P<0.001) and mean SI (0.75±0.07 vs 0.65±0.03, P=0.002) were higher in patients aged ≥50 years. Mean LOS was longer in older patients (5.22±1.14 vs 2.85±0.58 days, P<0.001). Older age was associated with SIRS on arrival (P=0.023) and associated with mortality (P=0.004).
Conclusion
Age ≥50 years is associated with greater severity of injury and poor outcomes for patients involved in low-velocity PMVCs. Increased clinical attention and resource allocation should be directed toward older patients after low-velocity PMVCs.
Acknowledgments
A version of this work was presented at the American College of Chest Physicians Meeting in Austin, TX on October 29, 2014.Citation24
Author contributions
All authors contributed toward data analysis, drafting and revising the paper and agree to be accountable for all aspects of the work.
Disclosure
The authors report no conflicts of interest in this work.