The Effect of Witness` Behavior on the Collapse to ED time Interval in out-of-hospital Cardiac Arrest

Purpose: The collapse-to-advanced life support (ALS) time interval is the most important factor for the survival of and the prognosis for patients suffering from out-of-hospital cardiac arrest. A witness is the key person who decides first response, the mode of transportation, and the activation of the emergency medical service (EMS). Accordingly, the time interval to ED arrival and ALS is mostly influenced by the witness factor. We analyzed the influence of the witness factor and examined how to reduce the collapse-to-ED time interval for cases of out-of-hospital cardiac arrest. Methods: We retrospectively reviewed 174 out-of-hospital cardiac arrest cases that occurred during a 1-year period. Then, we compared the time to call the EMS and the time to the ED arrival according to the witness’ type, the first response, the first place called and the mode of transportation to the ED. Results: The median time to call the EMS and time to ED arrival were 5 (0~30) and 55 (28~120) minutes, respectively. There was a statistically significant correlation between the time to call the EMS and the time to ED arrival. Family/Cohabitant comprised most (80.5%) of the witness and they had a statistically significant delay in the time to call the EMS and the time to ED arrival than other groups. The time to ED arrival was significantly longer for the group who contacted relatives as the first response than it was for other groups who called the EMS or directly transported the victim to the hospital. Among the first places called, the time to call the EMS and the time to ED arrival were significantly shorter for the witness group who called 119 first. As for the mode of transportation, the private ambulance group showed a significant delay in time to ED arrival compared to the 119 ambulance group and other groups. The victims who underwent CPR in the ED had significantly shorter times to call the EMS and to ED arrival than the other victims. Conclusion: The collapse-to-ED time interval was influenced mainly by the witness. The type of witness, the first response, and the first place called were significant factors that influenced the time to call the EMS and time to ED arrival. To improve the survival rate and the prognosis for out-of-hospital cardiac arrest victims, we need more education for people who might be witnesses of such an event.ope