Increasing the shockable rhythm and survival rate by dispatcher-assisted cardiopulmonary resuscitation in Japan

PURPOSE: This study aimed to examine the effectiveness of cardiopulmonary resuscitation (CPR) directions by dispatchers. We analysed the relationship of dispatcher-assisted bystander cardiopulmonary resuscitation (DA-BCPR) with favourable cerebral function, shockable rhythm rate, and emergency medical service (EMS) arrival time. METHODS: This nationwide study was based on CPR statistical data of out-of-hospital cardiac arrest (OHCA) patients (n = 629,471) from 1 January 2011 to 31 December 2015, and included 107,669 patients with bystander-witnessed cardiogenic cardiac arrest. The primary outcome was good brain function prognosis after 1 month, while the secondary outcome was the rate of shockable rhythm on ECG at the time of EMS arrival. EMS arrival time at the site was stratified into 7 min, 8−10 min, and 11−20 min using tertiles. Adjusted odds ratios (AORs) and 95% confidence intervals (95% CIs) were estimated using multivariate logistic regression analysis to assess the association between DA-BCPR and outcomes in each tertile. RESULTS: There were 37,269 (35%), 18,109 (17%), and 52,291 (49%) patients in the DA-BCPR, Only-BCPR, and no-BCPR groups, respectively. Compared to No-BCPR, DA-BCPR was associated with favourable neurological outcomes regardless of the time from 119 call to EMS contact (AOR, 1.56, 2.01, 1.82; 95% CI, 1.43−1.71, 1.80–2.24, 1.52−2.19; ≤7 min, 8–10 min, and 11–20 min, respectively). DA-BCPR showed association with the shockable rhythm rate upon EMS arrival regardless of the time 119 call to EMS contact (AOR, 1.30, 1.60, 1.90; 95% CI, 1.23−1.38, 1.51−1.70, 1.75–2.06; ≤7 min, 8–10 min, and 11–20 min, respectively). CONCLUSION: Providing dispatcher assistance with CPR to 119 callers improves the long-term outcome regardless of the patient’s age and EMS response time. Thus, encouraging dispatchers to promote BCPR is important for increasing the shockable rhythm rate and improving the brain function prognosis.