Background-Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) attempts to improve the management of out-of-hospital cardiac arrest by laypersons who are unable to recognize cardiac arrest and are unfamiliar with CPR. Therefore, we investigated the sensitivity and specificity of our new DA-CPR protocol for achieving implementation of bystander CPR in out-of-hospital cardiac arrest victims not already receiving bystander CPR. Methods and Results-Since 2007, we have applied a new DA-CPR protocol that uses supplementary key words. Fire departments prospectively collected baseline data on DA-CPR from January 2009 to December 2011. DA-CPR was attempted in 2747 patients; of these, 417 (15.2%) did not experience cardiac arrest. The sensitivity and specificity of the 2007 protocol versus estimated values of the previous standard protocol were 72.9% versus 50.3% and 99.6% versus 99.8%, respectively. We identified key words that may be useful for detecting out-of-hospital cardiac arrest. Multiple logistic regression analysis revealed that the occurrence of cardiac arrest after an emergency call (odds ratio, 16.85) and placing an emergency call away from the scene of the arrest (odds ratio, 11.04) were potentially associated with failure to provide DA-CPR. Furthermore, at-home cardiac arrest (odds ratio, 1.61) and family members as bystanders (odds ratio, 1.55) were associated with bystander noncompliance with DA-CPR. No complications were reported in the 417 patients who received DA-CPR but did not have cardiac arrest. Conclusions-Our 2007 protocol is safe and highly specific and may be more sensitive than the standard protocol.Understanding the factors associated with failure of bystanders to provide DA-CPR and implementing public education are necessary to increase the benefit of DA-CPR. (Circulation. 2014;129:1751-1760.)

Review: An increased number of rescuers may improve the survival rate from out-of-hospital cardiac arrests (OHCAs). The majority of OHCAs occur at home and are handled by family members.Materials and Methods: Data from 5,078 OHCAs that were witnessed by citizens and unwitnessed by citizens or emergency medical technicians from January 2004 to March 2010 were prospectively collected. The number of rescuers was identified in 4,338OHCAs and was classified into two (single rescuer (N=2,468) and multiple rescuers (N=1870)) or three (single rescuer, two rescuers (N=887) and three or more rescuers (N=983)) groups. The backgrounds, characteristics and outcomes of OHCAs were compared between the two groups and among the three groups.Results: When all OHCAs were collectively analysed, an increased number of rescuers was associated with better outcomes (one-year survival and one-year survival with favourable neurological outcomes were 3.1% and 1.9% for single rescuers, 4.1% and 2.0% for two rescuers, and 6.0% and 4.6% for three or more rescuers, respectively, (p=0.0006 and p<0.0001)). A multiple logistic regression analysis showed that the presence of multiple rescuers is an independent factor that is associated with one-year survival (odds ratio (95% confidence interval): 1.539 (1.088-2.183)). When only OHCAs that occurred at home were analysed (N=2902), the OHCAs that were handled by multiple rescuers were associated with higher incidences of bystander CPR but were not associated with better outcomes.Conclusions: In summary, an increased number of rescuers improves the outcomes of OHCAs. However, this beneficial effect is absent in OHCAs that occur at home. Word count 250