Improved Survival After Out-of-Hospital Cardiac Arrest and Use of Automated External Defibrillators
Background—In recent years, a wider use of automated external defibrillators (AEDs) to treat out-of-hospital cardiac arrest (OHCA) was advocated in The Netherlands. We aimed to establish whether survival with favorable neurologic outcome after OHCA has significantly increased, and if so, if this is attributable to AED-use.
Methods and Results—We performed a population-based cohort study, including patients with OHCA from cardiac causes between 2006 and 2012, excluding EMS-witnessed arrests. We determined survival status at each stage (to emergency room, to admission, to discharge) and examined temporal trends using logistic regression analysis with 'year-of-resuscitation' as independent variable. By adding each co-variable subsequently to the regression model, we investigated their impact on the Odds Ratio (OR) of 'year-of-resuscitation'. Analyses were performed according to initial rhythm (shockable vs. non-shockable), and AED-use. Rates of survival with favorable neurologic outcome after OHCA increased significantly (N=6133, 16.2% to 19.7%; P for trend=0.021), though solely in patients presenting with a shockable initial rhythm (N=2823, 29.1% to 41.4%; P for trend<0.001). In this group, survival increased at each stage, but was strongest in the pre-hospital phase (OR 1.11; 95% confidence interval 1.06 to 1.16). Rates of AED-use almost tripled during the study period (21.4 to 59.3%, P for trend <0.001), thereby decreasing time from emergency-call to defibrillation-device connection (median 9.9 to 8.0 min, P<0.001). AED-use statistically explained increased survival with favorable neurologic outcome, by decreasing the OR of 'year-of-resuscitation' to a non-significant 1.04.
Conclusions—Increased AED-use is associated with increased survival in patients with a shockable initial rhythm. We recommend continuous efforts to introduce or extend AED-programs.
- Received May 1, 2014.
- Revision received August 14, 2014.
- Accepted August 25, 2014.