New cars on the highways: Trends in injuries and outcomes following ejection.

Background: Although ejections from motor vehicles are considered a marker of a significant mechanism and a predictor of severe injuries and mortality, scant recent data exist to validate these outcomes. This study investigates whether ejections increase the mortality risk following a motor vehicle crash using data that reflect the introduction of new vehicles to the streets of a large city in the United States.

Methods: The Trauma and Emergency Medicine Information System of Los Angeles County was queried for patients ≥ 16 years old admitted following a motor vehicle crash between 2002 and 2012. Ejected patients were compared to nonejected. Primary outcome was mortality. A logistic regression model was used to identify predictors of mortality and severe trauma.

Results: A total of 9,742 (6.8%) met inclusion criteria. Of these, 449 (4.6%) were ejected; 368 (82.0%) were passengers and 81 (18.0%) were drivers. The rate of ejection decreased linearly (6.1% in 2002 to 3.4% in 2012). Compared to nonejected patients, ejected patients were more likely to require intensive care unit admission (43.7% vs 22.1%,  < .01), have critical injuries (Injury Severity Score > 25) (24.2% vs 7.3%,  <.01), require emergent surgery (16.3% vs 8.0%,  <.01), and expire in the emergency department (3.6% vs 1.2%,  <.01). Overall mortality was 3.6%: 9.6% for ejected and 3.3% for nonejected patients ( <.01). In a logistic regression model, ejection and extrication both predicted mortality (adjusted odds ratio: 1.83,  <.01 and 1.87,  <.01, respectively). Ejection also predicted critical injuries (Injury Severity Score > 25) with adjusted odds ratio of 2.48 ( <.01).

Conclusion: Ejections following motor vehicle crash have decreased throughout the years; however, they remain a marker of critical injuries and predictive of mortality.