We investigated whether DA-CPR would have the same effect as spontaneously-delivered bystander CPR.

A total of 37,899 witnessed cardiogenic out of hospital cardiac arrest (OHCA) selected from a nationwide Utstein-Japanese database between 2008 and 2012. Patients were divided into four groups as follows: CPR initiated with dispatcher assistance (DA-CPR; n=10,424), no CPR provided with dispatcher assistance (DA-No CPR; n=4658), spontaneously-delivered bystander CPR provided without DA (BCPR; n=6630), and both BCPR and dispatcher assistance was not provided (No BCPR-No DA; n=16,187). The primary endpoint was rate of shockable rhythm on the initial ECG, return of spontaneous circulation (ROSC) on the field. A multivariable logistic regression analysis was used. Adjusted odds ratios (AOR) are presented as 95% confidence intervals (95% CIs) among the groups.

The rate of DA-CPR implementation has gradually increased since 2005. In comparison with DA-No CPR, both spontaneously-delivered BCPR and DA-CPR were significantly associated with the following factors: increased rate of shockable rhythm on the initial ECG (AOR, 1.75 and 1.72; 95% CI, 1.67 to 1.85 and 1.63 to 1.83),improved field ROSC (AOR, 1.42 and 1.40; 95% CI, 1.33 to 1.52 and 1.30 to 1.51) and 1-month favorable neurological outcomes (AOR, 1.72 and 1.80; 95% CI, 1.59 to 1.88 and 1.64 to 1.97), respectively.

We found that the spontaneously delivered BCPR group showed favorable results. In comparison to the DA-No BCPR group, DA-CPR group resulted in the nearly equivalent effect as spontaneously-delivered BCPR group. Further standard dispatcher education is indicated.