Objective: To analyze the longitudinal changes in the treatment of out-of-hospital cardiac arrests. These analyses have focused on the time interval from the receipt of call until defibrillation of patients with ventricular fibrillation.
Design: Population-based, prospective longitudinal study according to the Utstein style.
Setting: Osaka Prefecture (population 8, 800, 000), served by 36 municipal fire and emergency departments.
Patients: Consecutive, out-of-hospital cardiac arrests occurring between May 1998 and April 2001.
Main outcome measures: Change in the interval to defibrillation, and one-year survival from cardiac arrest.
Results: Of the 15,211 cases of confirmed cardiac arrests during the three years, resuscitation was attempted in 14,609 subjects. Of the 2957 cases of cardiac origin and witnessed by bystanders, 90 cases (3.0%) were alive 1 year following the episode. In 383 cases of defibrillation, the interval from receipt of call to defibrillation was evaluated annually. This interval decreased significantly during the three year course (14.5, 13.0, and 11.5 min expressed by the median), suggesting that this project to report the data of out-of-hospital arrests was an effective campaign for EMT. However, the outcome did not improve significantly during this period (3.0%, 2.6%, and 3.6% alive 1 year in witnessed arrests with cardiac etiology). This may be because the third year median duration of 11.5 min, is still insufficient to indicate a significant improvement in the outcome.
Conclusions: This project to report the data of out-of-hospital cardiac arrest might have contributed to the reduction of the interval for defibrillation, as a campaign for the EMTs; although the decrease in this interval was still insufficient to result in a significant increase in the number of cases who are alive one year later.