Characteristics and Outcomes of Out-of-Hospital Cardiac Arrest Occurring While in a Motor Vehicle

This study aimed to investigate the incidence, patient characteristics, and outcomes of out-of-hospital cardiac arrest (OHCA) occurring while in a motor vehicle in Osaka City, Japan (with a population of 2.6 million), from 2009 to 2015. The OHCA data used in this study were obtained from the population-based Utstein-style registry in Osaka City. Patients who had OHCA occurring while in a motor vehicle were included. The primary end point was 1-month survival with favorable neurologic outcome after OHCA. During the study period, 18,458 OHCAs were observed, and 264 of them (1.4%) occurred while on or in a motor vehicle (drivers, n = 179; nondrivers, n = 85). The overall incidence rate of OHCAs occurring while in a motor vehicle was 14.0 per million population per year (drivers, 9.5; nondrivers, 4.5). In the drivers with OHCAs, 78 (43.6%) and 101 (56.4%) cases were of medical origin and traffic injuries, respectively. Approximately half of OHCAs with a medical origin in drivers presumably occurred while driving (46.2%, 36 of 78). The overall proportion of 1-month survival with favorable neurologic outcome after OHCA was 6.4% (17 of 264). In the drivers, the proportion of OHCAs with a medical origin and because of traffic injuries were 11.5% (9 of 78) and 2.0% (2 of 101) (p = 0.008), respectively. In conclusion, although OHCAs occurring while in a motor vehicle represented a small subset of the overall OHCA burden, a relatively large number of cardiac arrests with a medical origin occurred in drivers.